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BACKGROUND Inconclusive cytomorphology often results due to failure to distinguish between adenocarcinoma cells from benign, reactive, atypical mesothelial cells in effusion specimens. To resolve such dilemmas, auxiliary techniques like immunohistochemistry were utilised to reach a definitive diagnosis for better treatment and management of patients. We wanted to compare cytodiagnosis achieved on cell block preparations with the cytodiagnosis on conventional smear and perform immunohistochemistry for epithelial membrane antigen (EMA), calretinin, desmin, vimentin and E-cadherin on cell block preparation of the fluids in cases of indistinguishable cytomorphology of adenocarcinoma and reactive, atypical, and benign mesothelial hyperplasia. METHODS The immunohistochemical markers namely EMA, calretinin, vimentin, desmin and Ecadherin were applied on cell blocks employing streptavidin-biotin method. Immunohistochemistry was interpreted by giving scores to the percentage of stained cells. RESULTS EMA and E-cadherin had 100 % sensitivity in diagnosing adenocarcinoma whereas calretinin, vimentin and desmin were 100 % sensitive in diagnosing reactive, atypical mesothelial carcinoma on the cell block preparations. CONCLUSIONS Immunocytochemistry of fluid should be carried out on the cell block preparation where cytological diagnosis on conventional smear and cell block fails to detect malignant cells in the preparation. KEY WORDS Cell Block, Adenocarcinoma, Mesothelial Cells, Immunohistochemistry, EMA, Calretinin, Vimentin, Desmin, E-Cadherin

Background: Programmed death ligand-1 (PD-L1) assessed by immunohistochemistry (IHC) is used as biomarker for pembrolizumab therapy in advanced stage lung cancer patients. However, data permitting direct performance comparison between cytology and surgical specimen types are limited since both specimens from a single tumor site are infrequently available. In addition, alcohol fixation used with cytology specimens requires technical validation of the PD-L1 IHC assay before clinical use. We here report our experience with implementation of the PD-L1 22C3 IHC pharmDxTM assay for cytologic samples at a large tertiary cancer center. Study Design: Archival formalin-fixed (FF), paraffin-embedded cell blocks (CBs) and subsequent lung tumor resections (LTRs) from the same anatomical site were used for a direct comparison of PD-L1 tumor proportion scores (TPSs). TPS values were independently determined by one surgical lung pathologist and two cytopathologists blinded to the specimen pairs. An interim analysis was performed to facilitate the pooling of expertise among observers. After PD-L1 22C3 IHC pharmDxTM implementation for FF cytology specimens, dual-processed samples were used for a prospective technical validation of CytoLyt® prefixation (CF). Digital image analysis was performed for a subset of dual-processed specimens. Results: Eighty-one CBs and LTRs were included for comparison of the specimen types. PD-L1 assessment in CBs had an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 88.9/72.8, 66.7/73.5, 95.2/72.3, 80.0/65.8, and 90.9/79.1% for the ≥50/≥1% cutoff, respectively. The intraclass correlation coefficient was 0.84 (95% confidence interval [CI]: 0.76, 0.90), and it improved after interim analysis (before: 0.79 and after: 0.92). The overall concordance between CF and FF for the categories defined by the ≥50/≥1% cutoff values was 90.4% (95% CI: 79.0, 96.8). Similar assay performance was confirmed by digital analysis. Conclusions: PD-L1 22C3 IHC pharmDxTM shows good reliability if used with CB preparations. CF does not impact assay results significantly. Clinical validation with outcome data is needed, and digital methods of assessment should be further investigated.

Objective Primary retroperitoneal involvement of lymphoproliferative disorders is rare. Diffuse large B cell lymphoma (DLBCL) in the retroperitoneum has been scarcely reported and the diagnostic workup is challenging due to difficulties in access for tissue acquisition. Materials and methods A 73-year-old female presented with epigastric pain and nausea. A computed tomography scan revealed retroperitoneal lymphadenopathy. An EUS-FNA was performed and a cytological diagnosis of lymphomatous disorder was made on direct smears .A panel of immunocytochemical markers was applied on cell block preparations and revealed a EBV related DLBCL (CD20 positive, PAX-5 positive, CD3 negative, MUM-1 positive, BCL-2 positive, BCL-6 positive, CD10 positive, MIB-1 positive, and LMP-1 positive). Conclusion Our case illustrates the utility of EUS-FNA in the work-up of retroperitoneal lymphadenopathy and the importance of cell block processing in the diagnostic approach of EBV related DLBCL.

Background The identification of BRAF mutations in thyroid cancer has prognostic and therapeutic implications. Although the gold standard for identifying BRAF mutations is molecular testing, the ability to perform BRAF p.V600E immunostaining on fine-needle aspiration (FNA) samples can facilitate the rapid triaging of patients to treatment options. Methods A total of 50 thyroid carcinoma FNA samples, including papillary (29 samples), poorly differentiated (10 samples), anaplastic (9 samples), and Hurthle cell (2 samples) carcinomas, with a known BRAF p.V600E mutation status were selected for the current study. Immunostaining was performed on smears and cell block sections using an anti-BRAF p.V600E antibody (clone VE1). The results were compared with the known mutation status obtained by molecular testing and/or immunostaining of surgical pathology material from the same patient. Results Of the total of 50 cases, 26 cases had smears available for the evaluation of BRAF p.V600E immunostaining; positive immunostaining was noted in 16 samples and negative immunostaining was noted in 4 samples, whereas 6 cases were equivocal. Of the 34 cases for which cell blocks were available for evaluation, BRAF p.V600E immunostaining was positive in 17 cases, negative in 16 cases, and equivocal in 1 case. The overall sensitivity and specificity of BRAF p.V600E immunostaining on the cell block preparation was 94.4% and 100%, respectively, whereas for the smears it was 80% and 63.6%, respectively. Conclusions BRAF p.V600E immunostaining can be performed reliably on thyroid FNA cell block preparations. However, false-positive results on direct smears limit their utility and therefore need to be interpreted with caution. Cancer Cytopathol 2018;126:406-13. © 2018 American Cancer Society.

Objective Atypical squamous cells of undetermined significance (ASCUS) and atypical glandular cells (AGC) reflect cellular abnormalities insufficient for clear diagnosis. We used cell pellets obtained from liquid-based cytology (LBC) to prepare cell blocks (CB) and clarify the initial diagnosis of ASCUS and AGC. Study Design A total of 393 CBs with initial diagnosis of ASCUS or AGC were processed. Of those, 305 of the ASCUS and 20 of the AGC had adequate specimens. We compared results of CBs prepared from ASCUS and AGC to determine which had higher frequencies of higher-grade lesions. Results A majority of specimens (83%) were adequate for evaluation. Compared with the initial diagnosis, 14% (42/305) of ASCUS were diagnosed with low-grade squamous intraepithelial lesion (LSIL) in CB, while 10% (2/20) of AGC were diagnosed with LSIL or adenocarcinoma. No statistical relationship between the initial diagnosis of ASCUS and AGC and results of higher-grade lesions in CB is evident as determined by p value greater than 0.05 (p = 0.228). Conclusions CBs prepared from Liqui-PREP cell pellets are, in most cases, assessable and can be useful as an adjunctive test to help clarify the initial diagnosis of ASCUS and AGC. Diagn. Cytopathol. 2017;45:520–525. © 2017 Wiley Periodicals, Inc.

Myofibroblastoma (MFB) is a benign tumor of the mammary stroma with predominant myofibroblastic differention. The cytologic reports of MFB are very few in the available literature. From the cytodiagnostic point of view about 21 cases of MFB with cytological evaluation by fine-needle aspiration cytology (FNAC) have been encountered in the English-language literature: A 35-year-old woman presented with lump in the left breast. FNAC showed mild degree of pleomorphism with occasional groups with fibrous stroma and tumoral cells. A few benign epithelial cell groups were seen. Hematoxylin-eosin-stained sections of cell block preparation from the aspirate showed fascicles of spindle cells forming whorl structures. Three months later, excision biopsy was performed. The diagnosis was a classic variant of MFB. On immunohistochemical examination, sections were found to be highly positive for vimentin, CD34, and bcl- 2. In light of these findings, cell block material was retrospectively reviewed both morphologically and immunhistochemically. The findings of resection and cell block material were found to be very similar. MFB may cause a potential diagnostic pitfall while interpreting FNAC due to its wide differential diagnosis spectrum. We concluded that cytology and cell block findings complement each other. Diagn. Cytopathol. 2016;44:1064-1069. © 2016 Wiley Periodicals, Inc.

Objectives Programmed death-ligand 1 (PD-L1) is an emerging molecular target in anticancer therapy, most notably non–small cell lung cancers. PD-L1 expression in pancreatic adenocarcinomas (PDAs) on surgical specimens is highly variable, with 10% to 60% of tumors showing expression. PD-L1 expression in PDA on endoscopic ultrasound-guided fine needle aspirations (EUS-FNAs) has been rarely studied. Methods Formalin-fixed, paraffin embedded (FFPE) cell blocks (CBs) from 65 EUS-FNA samples of 55 patients, with a diagnosis of PDA, with at least 20% tumor cellularity were retrieved. The cell blocks were originally fixed in CytoRich fixative. Immunohistochemical staining (IHC) for PD-L1 was performed using the M365329-1 (22C3) clone according to the manufacturer’s approved protocol and optimized for the fixation method using appropriate controls. A combined positive score (CPS) defined per CAP guidelines as the total number of positive tumor cells and inflammatory cells as a percentage of the total number of tumor cells was assessed for each case and was grouped as 20. Results Twenty-five samples (38%) from 21 patients showed immunoreactivity to PD-L1, with 21 (32%) having a CPS of Conclusion Immunohistochemical analysis for PD-L1 is feasible on EUS-FNA CB samples when optimized and validated for the fixation method using appropriate controls. PD-L1 expression is seen in only a minority of PDAs, albeit with a very low CPS. The potential role of PD-L1 as a prognostic marker for disease progression needs further exploration.

Objectives: HER2 status of breast carcinoma is a powerful prognostic and predictive biomarker-particularly in the metastatic setting. Limited data is available regarding assessment of HER2 on cell block preparations (CBP). The primary objective of this study was to assess correlation between HER2 results obtained via immunohistochemistry (IHC) and fluorescence in-situ hybridization (FISH) in cases of metastatic breast carcinoma (MBC) on CBP. Secondary objectives included study of inter-observer variability in interpretation of HER2 on IHC, and concordance between HER2 results on CBP and formalin-fixed paraffin embedded material (FFPEM). Materials and Methods: Cases of MBC diagnosed on fine needle aspirates (FNA) with HER2 testing performed via IHC and FISH on CBP over 5 years (2010-2015) were reviewed. CBP material was fixed in an ethanol-based fixative (CytoRich Red Fixative system, BD). HER2 IHC was performed using polyclonal antibodies against Cerb-2 (Dako 0485). HER2 FISH testing was performed using the LSI HER2/neu/CEP17 probes (Vysis/Abbott Molecular Inc., Des Plaines, IL). Results: Seventeen cases (all female, median age: 59) were analyzed. 41% of CBP were products of bone FNA (7/17). Other sites included lymph node (3), lung (2), pleural fluid (2), liver (1), skeletal muscle (1) and mesentery (1). Median interval between diagnosis of primary carcinoma and FNA of metastasis was 5 years (range: 10 months-32 years). FISH was inconclusive due to suboptimal specimen quality in 2 cases. Correlation between IHC and FISH results was as follows: IHC 0/1+ (0/2; 0% amplification), IHC 2+ (2/12; 16.7% amplification) and IHC 3+ (0/1; 0% amplification). Inter-observer agreement of IHC scoring between 2 pathologists who independently reviewed IHC slides was fair (66.7% agreement, κ = 0.31). Comparison of HER2 results on CBP with FFPEM (primary carcinoma or metastasis) showed a high discordance and slight agreement (discordance rate = 37.5%; κ = 0.02). Conclusions: In this study, (a) 16.7% of MBC cases that scored 2+ on IHC showed amplification on FISH, (b) there was poor inter-observer agreement in HER2 scoring of IHC on CBP, and (c) there was high discordance between HER2 results obtained on CBP and FFPEM. Our results indicate that HER2 testing of MBC on CBP may be unreliable.

Evaluation of ER, PR and Her 2 are routinely performed on breast carcinomas. For accurate detection of these markers, compliance with the ASCO/CAP guidelines is recommended. Our previous study showed that alcohol fixation did not affect ER results when alcohol-fixed cell block (CB) sections were compared to formalin-fixed tissue sections, while PR and Her2 showed less concordance. The aim of this study was to evaluate and to compare ER, PR and Her2 IHC results on formalin-fixed CB sections to those observed on subsequent surgical (needle core or resection) specimens (SS). Fifty cases of formalin fixed CB samples obtained from primary (18%) and metastatic (82%) breast carcinomas were studied, all of which had subsequent SS available. ER, PR, and Her2 IHC studies were done on all samples and results were compared. ER results on formalin-fixed CB samples showed excellent correlation with SS (correlation coefficient cc = 0.82). While there was minimal improvement in PR results (cc = 0.433), Her2 detection did not improve by formalin fixation (cc = 0.439). Formalin fixation for CB preparations does not significantly improve the already good detection of ER positive breast tumors. The concordance rate in PR and IHC results between formalin-fixed CB and SS samples showed improvement as compared with the alcohol-fixed CB results. However, there was no improvement in detection of Her2 overexpression by using formalin fixation on cytology specimens.

BACKGROUND Cell block (CB) preparation during the endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS-TBNA) procedure plays an important role in the diagnosis of lung cancer and recovery of cellular material for molecular characterization of the tumor. However, the efficiency of the conventional method of CB preparation is suboptimal.

Objective Recent studies have validated the use of cytologic materials to determine HER-2/neu status. Good concordance has been shown between results obtained by immunocytochemistry (ICC), immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) on cytologic and surgical specimens. However, the utility of cytologic cell block material in determining HER-2/neu status has not been reported and is the subject of this study. Study Design HER-2/neu status was determined in 25 cases of primary or metastatic breast carcinoma by IHC and FISH. All cases were formalin-fixed, paraffin-embedded (FPPE) cell block preparations. ICC was performed using monoclonal antibodies TAB250 (Zymed) and CB11 (Novacastra Laboratories). FISH analysis was performed using the PathVysion HER-2 probe kit (Vysis, Inc.). Results of ICC and FISH were compared in each case. Results Of 25 cases studied, 17 showed no protein overexpression or amplification. Five cases showed protein overexpression and amplification. The remaining 3 cases showed 2+ staining intensity by ICC in 10, 20, and 50% of carcinoma cells, respectively, and all demonstrated lack of amplification. Conclusion Immunocytochemistry performed on FFPE cell block material is a reliable method for determining HER-2/neu status in cytologic specimens. We recommend routine preparation of FFPE cell block material in instances of suspected primary of metastatic breast carcinoma.

BACKGROUND Calretinin (CR) is a valuable marker in the immunohistochemical distinction between malignant mesothelioma (MM) and adenocarcinoma (ACA) in tissue sections. However, there is limited and conflicting data regarding the utility of CR in this differential diagnosis on cytologic material, especially cell block preparations. Also, the possible role of CR in the distinction of papillary serous borderline tumor (SBT) cells from reactive mesothelial cells in peritoneal washings has not been examined. METHODS Formalin-fixed paraffin-embedded cell block specimens of cytologic fluids, washings, and aspirates with a suspicious or positive cytologic diagnosis and a confirmed diagnosis of MM (29 cases), ACA (39 cases), and SBT (10 cases) were used for CR immunohistochemistry (IHC). RESULTS Moderate to strong staining in > 50% of tumor cells was noted in 26 of 29 (90%) MMs but in only 3 of 39 (8%) ACAs and 1 of 10 (10%) SBTs. Admixed reactive mesothelial cells (when present) were strongly positive in all fluid specimens, but the staining pattern of benign non-reactive mesothelial cells in washing specimens was less reliable. CONCLUSIONS CR is both a sensitive and specific marker of reactive and neoplastic mesothelial cells in cytologic cell block preparations and is thus useful in the differential diagnosis of MM and metastatic ACA in malignant effusions. However, CR IHC does not appear to allow definitive identification of SBT in peritoneal washings. Cancer (Cancer Cytopathol) 2000;90:312–9. © 2000 American Cancer Society.

OBJECTIVE: To evaluate the utility of immunohistochemical stains for desmin in discriminating mesothelial cells from adenocarcinoma in serous fluid cell block preparations. STUDY DESIGN: Cell block preparations from 22 cases (representing 18 patients) that were positive for carcinoma and 5 cases that were negative for malignancy were immunostained with an antibody to desmin. Positive staining was evaluated and scored semiquantitatively in both tumor cells and background mesothelial cells in the malignant cases and mesothelial cells in the negative controls. Staining was evaluated with a score of 0-3 for intensity and 0-5 for distribution. The sum of the two scores was recorded as the total score (TS). RESULTS: Mesothelial cells from all the carcinoma and benign cases stained with desmin (median TS = 5.5, range 4-8), typically strong in intensity and widespread in distribution. Positivity was observed in carcinoma cells in all cases, typically weak and focal (range 2-4). Using a total score of 4 as a cutoff for definitively positive staining, desmin staining was positive in mesothelial cells in 25/25 cases and carcinoma cells in 1/22 cases (P

Objective: Cervical cancer is one of the most common malignancies worldwide, yet it is preventable by population screening. In a previous study, we confirmed the feasibility of utilizing whole slide imaging (WSI) of cell block (CB) preparations to overcome the limitations of digitizing cytologic samples. In this study, we evaluated the accuracy of WSI in identifying various organisms and nonneoplastic findings. Study Design: A total of 335 WS images from Pap CB preparations were analyzed using the Aperio system. The test performance characteristics of ThinPrep (TP) and WSI samples were compared for adequacy, for the presence of bacterial vaginosis (BV), fungi, Trichomonas vaginalis (TV) and herpes simplex virus (HSV) and for nonneoplastic findings. Results: The WSI samples contained optimal material from all preparations. BV was diagnosed in 33 WSI versus 36 TP samples. Budding yeasts and/or pseudohyphal forms were noted in 18 WSI versus 19 TP samples. TV organisms (10 of 11 samples) and 1 HSV case were accurately identified in the WSI and TP samples. Squamous metaplasia, keratosis and reactive/reparative and inflammatory changes were easily identified by WSI. Conclusions: The concept of WSI from Pap CB preparations is potentially feasible for adoption. Digital remote web-based technology eliminates the need for an individual on site, saving time and resources.

Objective To evaluate the utility of CD10 immunostaining on cell block preparations from pelvic washing cytology material obtained during laparoscopy in cases of pelvic endometriosis (PE). Study design Six premenopausal women presenting with ovarian masses underwent a laparoscopic procedure. In addition to routine cytospin preparations, cell blocks were prepared using the formalin-fixed, paraffin-embedded method from the pelvic washings in each case. Immunocytochemistry using monoclonal antibodies for cytokeratin (CK) 7, CK20, CD10, estrogen receptor (ER), progesterone receptor (PR) and CA125 was performed on sections from cell blocks using the streptavidin-biotin peroxidase complex. Results Clusters of epithelial cells (3 cases) and stromal cells (2 cases) were seen in a background rich in hemosiderin-laden macrophages and poorly preserved mesothelial cells on cytospin smears. CD10 and CK7 were consistently positive in the stromal and epithelial components, respectively, in all cases on cell block sections. Variable staining reactions were noted for ER, PR and CA125. Conclusion CD10 immunostaining is a useful ancillary method in the diagnosis of endometriosis. Its routine use on cell block preparations from pelvic washings in women undergoing a laparoscopic procedure is recommended.

Endobronchial ultrasound-guided transbronchial needle aspiration has demonstrated its accuracy in the diagnostic workup of enlarged mediastinal lymph nodes. In addition to conventional smears, the use of liquid-based cytology (LBC) and cell block preparations (CBP) has been introduced more recently. The aim of our study was to determine the performance of each of the different techniques, separately and combined, in terms of diagnostic yield and sensitivity. A total of 290 consecutive patients were included. The pathological examination was based on smear cytology, LBC, and CBP. Adequate sampling was defined by the presence of pathological material or lymphocytes. The global diagnostic yield was 82.7 % and the sensitivity was 89.1 %. The diagnostic yield was 72.8 % for smears, 78.8 % for LBC, and 69.9 % for CBP. The combination of smears with CBP significantly increased diagnostic yield (p = 0.01) and sensitivity (p = 0.006), but not the combination of smears with LBC (yield: p = 0.07; sensitivity: p = 0.13). The combination of the three techniques further increased yield (p = 0.007) and sensitivity (p = 0.006), compared with smears alone. CBP were more sensitive than smears for both diagnoses of carcinoma (p = 0.01) and granulomatous inflammation (p = 0.048). Conversely, LBC was less sensitive than smears for granulomatous inflammation (p = 0.004), but the difference was not significant for carcinoma (p = 0.42). CBP, as a complement to smears, increases diagnostic yield and sensitivity for both diagnoses of carcinoma and granulomatous inflammation. LBC, if used alone, increases the risk of a false-negative result.

Objective: To determine the value of calretinin and cytokeratin (CK) 5/6 in discriminating mesothelioma from adenocarcinoma in serous effusion specimens. Methods: A total of 101 recent, histologically or clinically confirmed malignant effusions with immunostained cell block preparations were reviewed. The cases consisted of 34 mesotheliomas and 67 adenocarcinomas. This included 17 ascitic fluid and 84 pleural fluid samples. The adenocarcinomas included metastatic carcinomas from the breast (12), lung (19), stomach (3), colon (1), pancreas (2), ovary (6) endometrium (1) and 23 histologically confirmed metastases from unknown primary sites. The cases were assessed as negative or positive (>5% of cells stained). The staining pattern was recorded as cytoplasmic, cell membrane, nuclear or cytoplasmic and nuclear staining. Results: Calretinin staining was present in 97% (33/34) of the mesothelioma cases with a majority of them showing both cytoplasmic and nuclear staining (29/33). Only 3% (2/67) of adenocarcinomas were positive for calretinin, one being a lung adenocarcinoma and the other an adenocarcinoma of unknown primary site in an ascitic fluid. Cytokeratin 5/6 staining was also present in 33/34 (97%) of mesothelioma cases. Six (9%) adenocarcinomas were positive, including metastases from the lung (1), breast (1), ovary (2) and unknown primary site (2). Four of the six adenocarcinoma cases positive for CK5/6 were in ascitic fluids. No cases of mesothelioma were negative for both calretinin and CK5/6. Only one adenocarcinoma case, (which was from unknown primary site in an ascitic fluid sample), was positive for both markers. Conclusions: The results confirm that calretinin and CK 5/6 are useful markers for mesothelioma in effusion specimens. CK5/6 staining may be less useful for peritoneal fluid specimens where metastatic adenocarcinomas may be more likely to express the antigen. Further study of ascitic/peritoneal specimens is warranted. However, positive staining, particularly for both antigens, is highly indicative of a mesothelial origin for cells. The two markers make a useful addition to EMA and the panel of adenocarcinoma markers routinely applied to effusion specimens.

Serous tumors of low malignant potential are uncommon in women under 30-years-old peritoneal washings play an important role in the diagnosis and prognosis of ovarian neoplasms. Accurate diagnosis of peritoneal washings is important in determining therapeutic regimens and in determining patient prognosis. In peritoneal washings, these tumors can be difficult to distinguish from reactive benign mesothelial cells. The cases of four women with borderline serous ovarian tumors, all of whom were under the age of 25, and had peritoneal washings which were positive for papillary tumors were reviewed.

AIMS: To review consecutive cell block preparations of cytological specimens in a large general hospital. METHODS: 50 cell blocks were made over an 18 month period in which about 1900 fine needle aspirations (FNAs) were performed. The aspirator was a cytologist or, for image guided FNAs, a radiologist with a cytologist at hand to collect the specimen. Forty eight cell blocks were from FNAs and two were from serous fluids. RESULTS: The cellularity of the cell blocks was inadequate in only four preparations. The main motive for making cell blocks was to obtain tissue for immunohistochemistry. This was performed on 28 cases and a total of 107 immunostained sections were produced. The most common diagnostic dilemma was between carcinoma and melanoma, and the second most common between carcinoma and lymphoma. Consequently cytokeratin, S-100, and LCA were the most frequently used antibodies. At least one of these three antibodies was positive in 17 cases. Five cases were immunostained only for prognostic breast markers. CONCLUSIONS: The use of cell block immunohistochemistry is a reliable and technically unsophisticated aid in the cytological examination of tumours other than lymphomas. Success depends on having highly experienced aspirators that reliably obtain sufficiently cellular material.

Background The development of high-throughput drug screening (HTS) using primary cultures provides a promising, clinically translatable approach to tailoring treatment strategies for patients with cancer. However, this has been challenging for solid tumors because of often limited amounts of tissue available. In most cases, in vitro expansion is required before HTS, which may lead to overgrowth and contamination by non-neoplastic cells. Methods In this study, hematoxylin and eosin staining and immunohistochemical staining were performed on 129 cytopathology cases from 95 patients. These cytopathology cases comprised cell block preparations derived from primary tumor specimens or patient-derived xenografts as part of a pediatric precision oncology trial. Cytopathology cases were compared with the morphology and immunohistochemical staining profile of the original tumor. Cases were reported as tumor cells present, equivocal, or tumor cells absent. The HTS results from cytopathologically validated cultures were incorporated into a multidisciplinary tumor board report issued to the treating clinician to guide clinical decision making. Results On cytopathologic examination, tumor cells were present in 77 of 129 cases (60%) and were absent in 38 of 129 cases (29%), whereas 14 of 129 cases (11%) were equivocal. Cultures that contained tumor cells resembled the tumors from which they were derived. Conclusions Cytopathologic examination of tumor cell block preparations is feasible and provides detailed morphologic characterization. Cytopathologic examination is essential for ensuring that samples submitted for HTS contain representative tumor cells and that in vitro drug sensitivity data are clinically translatable.

Pleural fluid is a liquid located in the pleural cavity, between the pleural visceral and pleural parietal. Analysis of pleural fluid is mandatory in all cases of diseases that give rise to pleural effusion. Cytopathological test gives the first indication of malignancy in malignant effusion, one of which is by making cell block. The stages of making cell block begin with fixation to maintain the cell component and its state is close to the original. The purpose of this study was to determine the comparison of the quality of the cytopathological examination results from the manufacture of cell block using a fixative solution of Nathan Alcohol Formalin Substitute (NAFS) and alcohol 96% -NBF 10% in pleural fluid samples. Experimental research with cross-sectional research design. The results showed that 13 samples of pleural fluid preparations in cell block preparations with NAFS fixative solution and cell block preparations with 96%-NBF 10% alcohol fixative solution there was no significant difference in the morphological figure of the cells, the number of cells produced, the number of malignant cells analyzed, the absorption of staining and cytodiagnosis sensitivity. Based on the results of this study, it can be concluded that alcohol 96% -NBF 10% can be used as an alternative solution to fixative for pleural fluid samples.

BACKGROUND: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract, and the majority contain KIT or PDGFRA activating mutations. Fine-needle aspiration biopsy (FNAB) is a valuable technique in the diagnosis of GIST and may allow for preoperative therapy with tyrosine kinase inhibitors (TKI). Because of the morphologic diversity of these tumors, routine diagnosis of GIST often relies on C-Kit immunohistochemical staining in addition to morphologic findings. However, up to 15% of GISTs are C-Kit negative. Antibodies with increased sensitivity and specificity for detection of C-Kit–negative GIST cases may be of value, especially because some of these cases may also benefit from TKI therapy. METHODS: Immunohistochemical staining for DOG-1, C-Kit (CD117) and protein kinase C theta (PKCθ) was performed on FNA cell-block preparations representing 30 GISTs, 17 leiomyosarcomas, 16 melanomas, 16 schwannomas, 11 adenoid cystic carcinomas, and 8 leiomyomas. RESULTS: DOG-1 was found to have 100% sensitivity and 100% specificity in diagnosis of GIST. C-Kit demonstrated 70% sensitivity and 76% specificity, and PKCθ showed 40% sensitivity and 86% specificity. When only spindle-cell neoplasms were considered (adenoid cystic carcinomas excluded), the specificity of C-Kit increased to 89%. Of interest, all C-Kit–negative cases showed DOG-1 positivity. CONCLUSIONS: DOG-1 was the most sensitive and specific of the 3 markers for the diagnosis of GIST in cell-block preparations and may be of particular use in the diagnosis of C-Kit–negative GIST. Cancer (Cancer Cytopathol) 2011;. © 2011 American Cancer Society

Background The optimal volume of pleural fluid to diagnose a malignant effusion is unknown. Our study was designed to demonstrate if a minimum pleural fluid volume (10 mL) is equivalent to a large volume thoracentesis to make a cytopathologic diagnosis of malignancy. Methods A total of 121 thoracentesis samples were obtained from 102 patients with suspected or known malignant effusions. Pleural fluid was collected in three aliquots for cytologic examination (10 mL, 60 mL, ≥ 150 mL). The pathologist was blinded to patient identifiers and aliquot volume. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated for each volume for the diagnosis of malignancy. Results Pleural malignancy was diagnosed in 90 patient encounters (74.4%). For direct smear/cytospin, there was increased sensitivity and NPV for 60 mL ( P = .0058 and P = .045, respectively) and for ≥ 150 mL ( P P = .009, respectively) compared with 10 mL. For combined direct smear/cytospin and cell block preparations, statistical significance for sensitivity and NPV existed only between the 10 mL and ≥ 150 mL specimens ( P = .0099 and P = .033, respectively). No statistical difference existed for specificity or PPV for any aliquot volume. Conclusions The sensitivity for diagnosis of pleural malignancy is dependent on the pleural fluid volume extracted during thoracentesis. Volumes of 10 mL do not perform as well as larger volumes. When both direct smear/cytospin and cell block preparations are used, we recommend ≥ 150 mL, whereas when only direct smear/cytospin is used, 60 mL is adequate for the diagnosis a malignant pleural effusion.

Objective: To assess the diagnostic value of clot examination for satisfactory processing and confirmation of malignancy in serous effusions in routine cytological evaluation and compare the results with those of conventional smear and cell block preparations. Methodology: Body cavity fluids (n = 600) received in our laboratory were processed according to a pre-designed protocol for the study as follows: Day1: on receipt of the specimen, smears were made and a cell block was prepared from the sediment. Day2: after overnight sample storage of the remaining specimen at 2–8 °C all fluids were examined for the presence of a clot at the bottom of the container. Fluids in which clot had formed were fixed in formalin. The clot was then placed on a lens paper, wrapped and processed routinely. Diagnostic yields were compared. Results: In this study, we included 600 cases of serous fluids from pleural, pericardial and peritoneal effusions. In 73% (n = 437) of samples, clot formation was seen, while in 27%, (n = 163) no clot had formed. Routine smear and cell block preparations showed malignant cells in 9.6% (n = 42). However, with the addition of the clot preparation, the number of cases in which atypical/malignant cells were seen increased from 42 to 85 (19.4%), with a P

Context.—Immunohistochemical staining for cytokeratin 19 (CK-19) is a useful ancillary technique for diagnosing papillary thyroid carcinoma (papillary carcinoma) in histologic specimens. Although similar results have been obtained on aspirate smears, to our knowledge the utility of CK-19 immunolocalization in cell block preparations as an adjunct to fine-needle aspiration diagnosis of papillary carcinoma has not been examined. Objective.—The purpose of this study was to determine whether CK-19 immunostaining of cell block preparations of thyroid aspirates is a useful ancillary technique for diagnosing papillary carcinoma. Materials and Methods.—Using a monoclonal antibody to CK-19 and a standard avidin-biotin complex technique, immunostaining was performed on paraffin-embedded cell blocks of 57 cases with the following cytologic diagnoses: (a) papillary carcinoma (20 cases); (b) atypical cytology, cannot exclude papillary carcinoma (19 cases); and (c) nonneoplastic thyroid (18 cases). The staining reaction in each case was graded on the basis of percentage of epithelial cells stained (1+, 50). Tissue follow-up was available in all cases. Results.—Nineteen (95%) of 20 cases with an unequivocal diagnosis of papillary carcinoma were positive for CK-19 (3+). Tissue follow-up confirmed papillary carcinoma in all 20 cases. Of the 19 cases with a diagnosis of atypical cytology, cannot exclude papillary carcinoma, 7 (37%) cases displayed 3+ immunostaining and subsequent excision confirmed papillary carcinoma in all 7 cases. The remaining 12 cases with 1+ immunostaining included surgically confirmed goiter (6 cases), adenoma (2 cases), lymphocytic thyroiditis (3 cases), and papillary carcinoma (1 case). The follicular cells in 18 cases with a cytologic diagnosis of nonneoplastic thyroid showed 1+ immunostaining. Histologic follow-up of these cases confirmed the nonneoplastic cytologic diagnoses. Conclusions.—Cytokeratin 19 immunostaining of cell block preparations of thyroid aspirates serves as a useful tool for the diagnosis of papillary carcinoma. Strong immunostaining (3+) for CK-19 aids in accurate diagnosis of malignancy in cytomorphologically equivocal cases of papillary carcinoma.

BACKGROUND It has been shown that detection of the Wilms tumor susceptibility gene 1 protein (WT1) has diagnostic utility in the distinction of mesothelioma from adenocarcinoma in tissue sections of pleural tumors. This immunohistochemical study evaluates the effectiveness of WT1 as a marker for malignant mesothelioma in paraffin sections of cell block preparations derived from effusion specimens. METHODS The authors evaluated 111 cell blocks for WT1 immunoreactivity, including 14 mesotheliomas and 97 metastatic adenocarcinomas from various sites. RESULTS Nuclear reactivity for WT1 was observed in all samples of mesothelioma. However, only 22 of 97 samples (23%) of metastatic adenocarcinoma, nearly all of which were of ovarian origin (91%), exhibited nuclear reactivity for WT1. In 14 other samples (most of pulmonary derivation), WT1 staining restricted to the cytoplasm was observed for some tumor cells and was regarded as nonspecific. CONCLUSIONS Based on this staining profile, WT1 represents an effective marker for mesotheliomas in cell block preparations and can aid in its distinction from pulmonary adenocarcinoma. In assessment of effusion specimens with metastatic carcinoma, nuclear reactivity for WT1 is highly suggestive of an ovary primary tumor. Cancer (Cancer Cytopathol) 2002;96:000–000. © 2002 American Cancer Society.

Background Palpable thyroid nodules are present in 4-7% of general population and Fine Needle Aspiration (FNA) is now accepted by endocrinologists and thyroid surgeons as a safe, simple and cost effective procedure for evaluating a thyroid nodule. The obtained sample can be spread directly on slides, processed as cell block preparations or prepared as liquid base smears. Liquid base method has been recently accepted due to its shorter preparation time and better preservation of nuclear details. The aim of this study is to compare the diagnostic results of two commonly used methods: Liquid Base Preparation and Cell Block Preparation in evaluation of thyroid nodules. Methods The samples were taken from 100 patients with a solitary nodule or a prominent nodule on a multinodular goiter background (excluding hot nodules). The obtained samples were used to prepare conventional smears (CS), Cell Block Preparations (CBP) and Liquid Base Preparations (LBP). The slides were studied by two pathologists, considering the following parameters: Cellularity, Colloid, Lymphocytes/Plasma cells and Macrophages. Results 87% of cases revealed informative results in LBP method while in the same group of patients only 69% of samples were informative after processing by CBP method. Sensitivity and specificity of both methods compared with the conventional smears and with each other and it is concluded that LBP is a reliable method for evaluating of a thyroid nodule. Other studies also show the same results. Conclusion The liquid base method should be trusted due to its easier procedure, cleaner slide background, its higher specificity and higher diagnostic yields. It can be used instead of CBP and in association with CS to increase the accuracy of evaluation of thyroid nodules.

Background: Amyloidosis is menacingly increasing medical problem in aging population across globe. Its clinical presentation is varied. Its laboratory diagnosis often requires biopsy material. The fine needle aspiration cytology (FNAC, FNAB) offers dependable diagnostic alternative to cumbersome biopsy. Present protocol describes the FNAC of abdominal pad of fat as surrogate site for diagnosis of senile systemic amyloidosis avoiding biopsy other known sites. Aim: To study diagnostic accuracy of subcutaneous abdominal fat tissue fine needle aspiration cytology/biopsy for detecting systemic (senile) amyloidosis and its utility in clinical practice. Objectives: To diagnose systemic amyloidosis (senile) by fine needle aspiration cytology/biopsy of abdominal fat pad on crush smears of aspirates and cell blocks. To correlate the diagnosis of deposits of amyloid with the clinical manifestations in specific and non specific clinical manifestations of amyloidosis. To know the sensitivity and specificity of the diagnosis of amyloid deposition on fine needle aspiration cytology/biopsy of abdominal fat pad in comparison to the results of cell block preparations. Methodology: A prospective study carried out to compare results of FNAC of abdominal pad of fat with paraffin embedded cell block in diagnosis of amyloidosis in suspected cases of cases of senile systemic amyloidosis. Technical adopted methods to be used are regular tissue stains, congo red stain and polarized microscopy. Expected Results: It is expected that results of study will establish FNAC of abdominal pad of fat as dependable office diagnostic procedure that would avoid complicated biopsy procedures of gastrointestinal tissue, skin, bone marrow and others for senile systemic amyloidosis.

BACKGROUND: Fine needle aspiration biopsy (FNAB) affords a less expensive, less morbid approach to masses within the complex anatomy of the mediastinum as opposed to surgical biopsy. Given the current state of computed tomography guidance and the available cell block preparations and ancillary studies, definitive diagnosis of mediastinal tumors is possible. CASE: A 19-year-old male presented with weight loss and muscle weakness. Computed tomography revealed an anterior superior mediastinal mass with attachment to the posterior sternum and anterior aorta. FNAB yielded hyperchromatic cells with densely clumped chromatin and prominent nucleoli. These were present as single cells and clusters. Cell block preparations were studied with immunoperoxidase methods and were strongly positive for chromogranin and glucagon, supporting the diagnosis of carcinoid tumor. Surgical excision yielded a 7-cm, unencapsulated, red-brown tumor with medium-sized cells with oval to round nuclei, scant and granular cytoplasm and coarse salt and pepper chromatin with prominent nucleoli. The cells were arranged in islands and bands and were associated with prominent capillaries and dense, collagenous septae. Immunoperoxidase and electron microscopy demonstrated numerous intracytoplasmic, nonspecific neuroplasmic, nonspecific neurosecretory granules and positivity for somatostatin, synaptophysin, cytokeratin and chromogranin. CONCLUSION: FNAB affords an accurate and timely diagnosis of an anterior mediastinal tumor without the necessity for open biopsy and also offers accurate surgical planning and decreased morbidity.

Background: Early detection of pancreatic adenocarcinomas is essential for improving survival. In this regard, endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNAC) has established itself as the method of choice for its ability to target lesions smaller than those which could be targeted by the traditional imaging methods like transabdominal ultrasound. Identifying these tumors correctly on FNA may be challenging because pancreatic adenocarcinomas may show a wide range of morphological features and the presence of contaminants from the gastrointestinal tract may show up as potential pitfalls. This study presents detailed cytomorphological analyses of 59 cases reported as pancreatic adenocarcinomas on smears and cell blocks. The clinical and histopathology follow-up data wherever available have also been presented. Materials and Methods: EUS-FNAC smears and cell blocks from cases reported as pancreatic adenocarcinomas were retrospectively evaluated with individual assessments of a range of features related to cellularity, cellular arrangement, cytoplasmic qualities, and nuclear features. Aspirates from peripancreatic lymph nodes, histopathology sections, and clinical records were reviewed wherever available. Results: Nonneoplastic cells like pancreatic ductal cells and acinar cells, duodenal, and gastric epithelia were detected along with neoplastic cells showing a wide range of variations in different cytomorphological characters. Often, a mixture of features was noted in the same case. Cell block preparations served as useful adjuncts since they made it possible to render unequivocal diagnoses of malignancies in cases where smears were hypocellular. Conclusion: The study creates a useful knowledge base of cytomorphological features of pancreatic adenocarcinomas.

CD138 (Syndecan-1) is a transmembrane heparan sulfate proteoglycan present on the surface of plasma cells and epithelial cells. CD138 is also expressed in some hematopoietic neoplasms and has recently been observed in carcinomas. We characterized CD138 expression in cell-block preparations of fluids/effusions, focusing on the distinction between carcinoma and mesothelioma. One hundred formalin-fixed, paraffin-embedded cell-block sections of fluids/effusions consisting of 58 metastatic carcinomas, 24 mesotheliomas, 11 reactive mesothelial cell proliferations, 3 lymphomas, 3 metastatic sarcomas, and 1 metastatic melanoma were stained with a monoclonal antibody against CD138. CD138 staining was observed in 32/58 (55%) metastatic carcinomas and 2/24 (8%) mesotheliomas; all reactive mesothelial cells, lymphomas, sarcomas, and melanoma were negative. CD138 is a highly specific marker in the differential diagnosis of carcinoma vs. mesothelioma. Distinct membranous staining without background staining of most inflammatory cells makes CD138 an ideal marker for cell-block preparations of fluids/effusions. It should be an integral component of the epithelial-mesothelial antibody panel.

Background Acinic cell carcinoma (AcCC) is diagnostically challenging on fine-needle aspiration because it can mimic several other neoplasms or even normal acinar tissue. Immunopositivity for DOG1, especially circumferential membranous staining, can support the diagnosis of AcCC but is not entirely specific, and it is prone to technical and interpretive challenges on small specimens. NR4A3 (nuclear receptor subfamily 4 group A member 3) translocation and nuclear NR4A3 overexpression were recently described in the majority of AcCCs. Here, the authors evaluate the performance of NR4A3 immunohistochemistry (IHC) and NR4A3 break-apart fluorescence in situ hybridization (FISH) on cell block preparations and compare them with DOG1 IHC in distinguishing AcCC from other entities in the differential diagnosis. Methods The authors identified 34 cytology cell blocks with lesional cells, including 11 specimens of AcCC (2 of which derived from 1 patient and showed high-grade transformation) as well as 2 secretory carcinomas, 7 salivary duct carcinomas, 4 mucoepidermoid carcinomas, 3 oncocytomas, 3 renal cell carcinomas, and 6 specimens containing nonneoplastic salivary gland tissue. NR4A3 IHC, DOG1 IHC, and NR4A3 FISH were attempted for all cases. Results NR4A3 IHC had 81.8% sensitivity and 100% specificity for AcCC, whereas NR4A3 FISH had 36.4% sensitivity and 100% specificity, although 4 cases (3 mucoepidermoid carcinomas and 1 salivary gland tissue sample) could not be analyzed because of low cellularity. Notably, no normal acinar tissue specimens showed NR4A3 positivity by IHC or FISH. In addition, DOG1 IHC had 72.7% sensitivity and 92% specificity. Conclusions NR4A3 IHC is highly specific for the diagnosis of AcCC and is more sensitive than DOG1 IHC and NR4A3 FISH. In addition, NR4A3 IHC performance is not improved by the inclusion of DOG1 IHC. Finally, NR4A3 positivity resolves the perennial problem of distinguishing AcCC from normal acinar tissue.

Extramedullary multiple myeloma (EMM) involving the liver as a focal space-occupying lesion is very rare, especially in the patients with cirrhosis. Here, we report a case of EMM in the liver and periportal lymph node, diagnosed by endoscopic ultrasound guided-fine-needle aspiration (EUS-FNA). A 57-year-old male patient, with history of cirrhosis, presented with abdominal pain and pancytopenia. The abdominal magnetic resonance imaging (MRI) demonstrated a 6.5 cm left hepatic mass with a 1.1 cm malignant-appearing periportal lymph node and diffuse osseous lesions. The cytology specimens from the hepatic mass and the periportal lymph node were obtained through EUS-FNA without rapid on-site evaluation (ROSE). The thin-layer preparations (ThinPrep) showed abundant plasmacytoid cells, which were confirmed to be Kappa-restricted neoplastic plasma cells by the cell block preparations. Later, his serum level of Kappa light chain was found significantly elevated by flow cytometry, which was identified as monoclonal IgA Kappa light chain by serum protein electrophoresis (SPEP) with immunofixation. The patient was diagnosed as IgA multiple myeloma with extramedullary involvement of the liver and periportal lymph node. This is the first case showing the ThinPrep cytomorphologic features of EMM in the liver and periportal lymph node. This case highlights the importance of distinguishing plasma cells from being hepatocytes and lymphocytes on the ThinPrep and also emphasizes the utility of the cell block in the diagnosis of plasma cell neoplasm.

Aim To explore the cytological spectrum of the gastrointestinal stromal tumour (GIST) including its metastatic sites. Material and methods A total of 42 patients (45 sites) diagnosed with GIST or its metastases on fine needle aspiration cytology were studied over a period of 5 years. May-Grunwald Giemsa- and haematoxylin and eosin-stained smears were reviewed and analysed for the cytomorphological spectrum of GIST. Results Primary GIST alone was seen in 24 cases, E-GIST in eight cases and metastasis in 11 cases (one patient showing metastasis at two distinct sites), whereas concurrent primary and metastatic lesions were noted in two cases. Amongst primary sites, the most commonly affected location was stomach (n = 22), followed by ileum (n = 2), duodenum (n = 1) and rectum (n = 1). Extra-GIST was seen in retroperitoneum and pelvis (n = 3 each), omentum and mediastinum (n = 1 each). Fine needle aspiration cytology was done from 11 metastatic sites of GIST which included liver, gall bladder fossa, chest wall, and thigh. The classic spindle cell arrangement was the predominant cytological pattern. About 8.8% cases showed predominant epithelioid cell morphology and 15.5% cases had a mixed cytomorphology comprising of both spindle cell and epithelioid cell patterns. Nuclear pseudoinclusions, perinuclear vacuoles and multinucleation were seen in four cases. Immunocytochemistry on cell-block sections for confirmation was performed in 18 cases and all these cases showed strong c-KIT positivity. Conclusion In this largest case series of cytomorphological diagnosis of GIST, we describe the cytomorphology and immunocytochemistry of primary and metastatic GIST. GISTs with predominant epithelioid cell morphology may pose a diagnostic dilemma therefore in all suspected cases of GIST, immunocytochemistry for c-KIT and/or DOG1 should be employed on cell-block preparations to confirm the diagnosis of GIST.

Angiomyolipoma is a benign mesenchymal lesion that occurs most commonly in the kidney. Its occurrence in the liver is relatively rare. We report two cases of hepatic angiomyolipoma diagnosed by ultrasound-guided, needle aspiration biopsy. One of the patients was a previously healthy 62-yr-old woman who presented with a hepatic mass incidentally during a healthy examination. The other patient was a 67-yr-old man, a victim of chronic hepatitis C, who was found to have a hepatic tumor in the right lobe during regular follow-up. Cytologic preparations of the two hepatic masses showed some mature adipocytes admixed with clusters of variable-sized mesenchyme-like cells with fibrillar cytoplasm and indistinct cytoplasmic borders. Some of the cells were round to oval and others were spindle shaped with oval, cigar-shaped or elongated nuclei. The nuclear chromatin was fine and some cells showed round nucleoli. No thick-walled blood vessels were noted in the cytological smears. In the cell block preparations, a mixture of thick-walled blood vessels, mature adipose tissue, and bundles of variable-sized smooth muscle cells were noted. The spindle or epithelioid smooth muscle cells were positive for vimentin, α-smooth muscle actin, and human melanoma black (HMB)-45 but negative for desmin and S100 protein in immunohistochemical stains. The purpose of the current study is to describe cytological features of this lesion with differential diagnosis because pathologists may be called on to render a diagnosis on needle aspiration. HMB-45 has been proved to be a sensitive marker for the smooth muscle component of angiomyolipoma. Cell block preparations assisted with immunohistochemical staining should be emphasized for definite diagnosis. Although a surgical procedure may still be necessary once a diagnosis of angiomyolipoma is made, treatment may be tailored for a less aggressive procedure than for malignant hepatic nodules. Diagn. Cytopathol. 2004;31:263–266. © 2004 Wiley-Liss, Inc.

BACKGROUND Cell blocks can be prepared from residual thin-layer cervicovaginal (ThinPrep) material and can be used in immunohistochemical staining assays for p16INK4a and Ki-67, which are surrogate markers related to human papillomavirus infection and cell proliferation, respectively. The objectives of the current study were 1) to investigate the feasibility and the role of cell block preparations in identifying significant neoplastic and preneoplastic lesions of the uterine cervix and 2) to assess the feasibility of using p16INK4a and Ki-67 immunohistochemical staining patterns on cell blocks to identify significant preneoplastic cervical lesions. METHODS Cervicovaginal cytology specimens from 85 patients were analyzed. Cytologic diagnoses based on ThinPrep Papanicolaou test results were as follows: squamous cell carcinoma was diagnosed in 3 specimens, high-grade squamous intraepithelial lesions (HSIL) were diagnosed in 27 specimens, low-grade squamous intraepithelial lesions (LSIL) were diagnosed in 20 specimens, and atypical squamous cells of uncertain significance (ASCUS) were diagnosed in 11 specimens. Diagnoses of negativity for intraepithelial lesions or malignancy (NILM) were made in 24 specimens. Cell block sections were stained with hematoxylin and eosin and were immunostained with antibodies against p16INK4a protein and Ki-67 antigen. RESULTS The cytomorphologic diagnoses made using cell block preparations were as follows: SCC in 2 specimens, HSIL in 20 specimens, LSIL in 30 specimens, NILM in 32 specimens, and no diagnosis in 1 specimen. In 62 cases (73%), the diagnoses made using cell block preparations were in agreement with the ThinPrep diagnoses. Immunostaining of cell blocks for p16INK4a and Ki-67 exhibited a statistically significant association (P < 0.05) with the presence of significant lesions on either cell block or ThinPrep analysis. CONCLUSIONS To the authors' knowledge, p16INK4a has not been analyzed previously in ThinPrep cell blocks, and the correlation between Ki-67 expression and cell block diagnoses also has not been reported previously. The current results indicate that cell blocks prepared from residual ThinPrep material represent an additional reliable diagnostic tool in the evaluation of cervical samples. Furthermore, immunohistochemical studies may be helpful in differentiating significant preneoplastic changes from other cervical lesions, such as atrophy. Cancer (Cancer Cytopathol) 2004. © 2004 American Cancer Society.

Mesothelial cell hyperplasia, collagen balls, endometriosis, and endosalpingiosis are diagnostic pitfalls on peritoneal washing cytology in women who present with gynecologic lesions. Over an 8-month period, the peritoneal washings from 10 patients undergoing gynecologic surgery for presumed malignancy showed unusual cytologic findings, several of which posed diagnostic difficulties. The washings from four patients with ovarian carcinomas were cellular and contained clusters and strips of cells with cytologic atypia mimicking malignancy. Confirmation of their benign mesothelial origin was confirmed on immunohistochemistry utilizing cell block preparations. In two cases of endometrial endometrioid carcinoma, the washings contained several clusters of cells surrounding and/or admixed with a globular substance. Due to their similarity to endometrial cells, immunohistochemistry was performed on cell block preparations. The cells were positive for cytokeratin and negative for carcinoembryonic antigen and B72.3, confirming their mesothelial origin. In one case, clinically presumed to be a malignant mass, the washings contained tight clusters of cells with mild cytologic atypia admixed with hemosiderin-laden macrophages. In conjunction with the cell block findings, a diagnosis of endometriosis was made. Extensive endometriosis was found on the surgically resected specimen. In two cases, strips of ciliated epithelial cells resembling tubal epithelium were present on the cytologic and cell block preparations, consistent with endosalpingiosis. The peritoneal washings in one case contained several clusters and balls of atypical cells surrounding microcalcifications on cell block preparation. Since calcification within groups of cells in peritoneal washings always raised the possibility of malignancy, a serous carcinoma of the ovary, particularly of borderline malignancy, would have to be excluded. Fortunately, the resected specimen was free of tumor and showed calcified endosalpingiosis on the ovarian surface. Preparation of cell blocks from peritoneal washings is of value in the work-up and management of patients who present with cytologic mimickers of malignancy on fluid cytology. Diagn. Cytopathol. 2003;28:335–341. © 2003 Wiley-Liss, Inc.

Cytology specimens play an important role in the diagnosis and predictive testing of lung cancer. While morphological characterisation of small cell and non-small cell lung carcinomas (NSCLC) on cytology is possible, further subtyping of NSCLC into adenocarcinoma and squamous cell carcinoma morphology is also mandatory in the current era of personalised medicine. Notably, cytology specimens in different forms (fine needle aspiration, exfoliative, and cell block) with or without immunocytochemistry are reliable sources for accurate diagnosis of adenocarcinoma and squamous cell carcinoma as evidenced by numerous studies present in the literature. However, there are instances where subtyping of NSCLC based on morphology alone is challenging on cytology samples, especially non-cell block preparations. In this paper, we will discuss current concepts, advances, and challenges of subtyping NSCLC in cytology specimens.

Double-hit lymphoma is typically categorized as “high-grade B-cell lymphoma, with MYC and BCL2 and/or BCL6 rearrangements”, but in infrequent cases in which terminal deoxynucleotidyl transferase (TdT) expression is positive, it is categorized as B-lymphoblastic lymphoma (B-LBL). BCL2 rearrangements are usually caused by t(14;18)(q32;q21); variant translocations are very rare. Here, we describe an unusual case of double-hit pancreatic B-LBL with a variant translocation t(2;18)(p11;q21). A 69-year-old man was admitted because of an abdominal mass. Computed tomography scans demonstrated a diffusely enlarged pancreas and massive ascites. Cell block preparations of ascites cells revealed marked proliferation of blastic lymphoid cells positive for CD19, CD10, CD79a, PAX5, and TdT, indicating a diagnosis of B-LBL. G-banding and spectral karyotyping showed 45,XY,+X,t(2;18)(p11;q21),-4,der(5)t(1;5)(q12;p15),der(6)t(6;21)(q21;q?),t(8;14)(q24;q32),-15. Fluorescence in situ hybridization detected split BCL2 and IGH/MYC fusion signals. Almost all ascites cells were diffusely and strongly positive for MYC and BCL2. The patient died of progressive disease 20 days after admission. To our knowledge, this is the first reported case of MYC and BCL2 double-hit B-LBL with t(2;18)(p11;q21). High coexpression of MYC by t(8;14) and BCL2 by t(2;18) may be implicated in the development of B-LBL. Furthermore, double-hit B-LBL may be associated with a less favorable outcome compared with typical B-LBL.

Background: Cytology is rapidly progressing from a primary screening investigation to a definitive diagnostic modality in increasing number of cases. This has been made possible by the use of ancillary tests such as immunochemistry, and molecular techniques. Over the years, the use of immunochemistry has evolved from being just an adjunct to diagnosis, to determining primary site of malignancy and exact typing of malignancies. This study was conducted to find out the impact of immunochemistry performed on cell blocks and smears of varied cytology material including FNAC material and fluids. Methods: It was a retrospective study. All cytology cases including FNAC material and fluids on which immunochemistry had been performed were retrieved from records. Immunochemistry was performed manually on cold acetone fixed smears, and cell-block preparations. Result: A total of 50 cases were evaluated from past two years, including 10 cases of fluids, and 40 cases of FNAC material. Staining was done on cell blocks in 44 cases, and on smears in 6 cases. In 15 cases, immunochemistry was performed to find out the site of primary malignancy, of which in 11 cases, it was positively contributory in giving a list of possible primaries and in 4 cases, single definitive diagnosis was provided. In 27 cases, it helped in typing of malignancies, and providing additional information. It was non-contributory in 8 cases. Conclusion: Immunochemistry, on smears as well as cell blocks is a useful adjunctive tool in cytology, therefore, it is advised to perform immunochemistry wherever possible.

Purpose To report pathologic evaluation and diagnostic yield of an aspiration cutter-assisted biopsy of anterior segment tumors. Design Retrospective, consecutive, interventional case series. Methods Fifty-five eyes of 55 patients with iris and iridociliary tumors underwent an aspiration cutter-assisted biopsy at a single institution. Cytospin and cell-block preparations were performed on all biopsy samples. Bleached preparations and a panel of immunohistochemical stains were performed in selected cases. Cytologic diagnosis was correlated with clinical diagnosis and with histopathologic diagnosis, when available. Main outcome measures were (1) specimen cellularity, (2) diagnostic studies performed, (3) cytopathologic diagnosis, and (4) concordance with histopathologic diagnosis. Results Specimen cellularity was adequate for cytopathologic interpretation of cytospin preparations in 55 (98.2%) of 56 biopsies. Twenty-three (41%) of 56 biopsy samples had diagnostic material in cell-block preparations. The most common cytopathologic diagnoses were melanoma (n = 39/56; 69.6%), melanocytoma (n = 4/56; 7.1%), nevus (n = 4/56; 7.1%), lymphoma (n = 2/56; 3.6%), and epithelial implantation cyst (n = 2/56; 3.6%). One biopsy sample (1.8%) yielded nondiagnostic material. Wide incisional or excisional biopsy confirmation was available in 13 (23.2%) of 56 aspiration cutter-assisted biopsy cases. Cytopathologic diagnoses were consistent with histopathologic diagnosis in 12 (92.3%) of 13 cases. Conclusions Although specialized pathologic techniques were necessary to maximize material available for diagnosis, all biopsies yielded cellular material and 41% yielded diagnostic tissue in cell block preparation. Although lower than the yield of wide incisional or excisional biopsy, aspiration cutter-assisted biopsy of anterior segment tumors achieved a diagnostic yield of 98.2%.

The presence of Paracoccidioides brasiliensis was determined in sputum samples from 50 patients with paracoccidioidomycosis using four different techniques: (a) cell-block preparations stained with silver methenamine, (b) direct microbiologie examination, (c) smears stained with Shorr, and (d) smears stained with silver methenamine. Overall, cell-block preparations and smears stained with silver methenamine proved to be the most sensitive techniques, followed by smears stained with Shorr and direct microbiologic examination in decreasing order of sensitivity. Sputum cytology tended to be less positive in patients with interstitial pulmonary lesions as determined by chest X-ray than in patients with alveolar lesions. In addition to its high sensitivity, cell-block preparation technique allows storage of blocks and slides for further studies.

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors that can affect any part of the body. They can be sporadic or arise in the setting of tuberous sclerosis (TSC). In this article, we report a series of three hepatic and two pancreatic PEComas diagnosed preoperatively with ultrasound-guided fine needle aspiration (FNA). All patients were female (age range 28-70), had no personal history of TSC and presented with a single, localized painless mass. Rapid on-site evaluation (ROSE) of cytologic samples was performed for all cases to evaluate for cellular content and adequacy of specimens. Direct smears and cell block preparations revealed a proliferation of medium to large polygonal epithelioid cells, with abundant eosinophilic and vacuolated cytoplasm, arranged in sheets and nests. On immunohistochemistry (IHC), neoplastic cells showed co-expression of melanocytic and smooth muscle markers and a diagnosis of PEComa was rendered. PEComas of the pancreas and liver are rare neoplasms, but should always be considered when examining "clear cell" neoplasms, especially in young female patients. If good quality cytologic samples are obtained by FNA, a correct diagnosis can be achieved with the help of IHC. This is of particular importance in order to plan adequate surgical strategy and to avoid overtreatment.

Background To report two cases with idiopathic unilateral diffuse opacification of the posterior hyaloid membrane (PHM) completely separated from the retina, the mechanism of which is possibly due to glial cell proliferation and migration. Case presentation Two Japanese women at age 75 and 84 with no systemic or ocular history developed diffuse opacification in one eye resembling a ground glass sheet almost all over the surface of the PHM, but not within the vitreous gel or fluid. The retinas were funduscopically normal; however, optical coherence tomography demonstrated hyperreflective icicle-like anterior protrusions from the surface of the fovea. The patients received pars plana vitrectomy, resulting in visual improvement. Cell block preparations of the vitreous in one case revealed a cluster of cells immunoreactive for glial fibrillary acidic protein in consistence with gliosis, while denying vitreoretinal lymphoma from lack of atypical cells and vitreous amyloidosis due to no staining for Congo red or direct fast scarlet. The lesions did not recur during follow-up with no new funduscopic abnormalities. Conclusions To our knowledge, this is the first to demonstrate such peculiar cases of vitreous opacity with idiopathic and unilateral onset. Histological assessments revealed the possible pathogenesis of gliotic opaque PHM separation to cause its ground-glass-sheet appearance.

Background The success of cell block preparation is crucial for ancillary diagnostic tests in cytology. However, achieving an optimal cell block can be challenging. The current study describes a self-clotting-based technique for fine-needle aspiration (FNA) cell block preparations and evaluates its usefulness in comparison with the conventional needle wash technique. Methods The clinical data, FNA procedure, and cellularity of cell blocks of the self-clotting group (37 cases) and the conventional needle wash group (33 cases) were compared. The cellularity was evaluated using a scoring system (0 indicated acellular, 1 indicated 1-50 cells, and 2 indicated >50 cells). Results Approximately 76% of cases in the self-clotting group received a score of 2 versus 36% in the conventional needle wash group. Approximately 14% received a score of 1 in the self-clotting group compared with 9% in the conventional needle wash group, whereas 11% in the self-clotting group received a score of 0 versus 55% in the conventional needle wash group. The differences between the 2 methods were statistically significant. Conclusions The results of the current study demonstrate that the self-clotting method is superior to the conventional needle wash method for FNA samples. Cancer Cytopathol 2018;126:190-9. © 2017 American Cancer Society.

Intraocular lymphoma is a rare neoplasm that occurs only in the eyes and/or central nervous system. Diagnosis of intraocular lymphoma is difficult because its clinical manifestations mimic chronic uveitis. Pathological examination of the vitreous is one of the main diagnostic tools for intraocular lymphoma, but this is challenging due to the sparse cellularity and specimen degeneration. Here, we reviewed 33 cell block preparations from vitreous perfusion fluid in order to examine the significance of cytopathological findings for differential diagnosis using vitreous samples. The cases comprised 12 intraocular lymphomas and 21 non-lymphomatous diseases. Cytologically, vitreous samples from non-lymphoma cases showed lower cellularity than the lymphoma cases. Whereas vitreous material from cases with infectious endophthalmitis showed prominent neutrophilic infiltration, material from sarcoidosis cases showed infiltration of small lymphoid cells, especially CD4-positive T cells. On the other hand, lymphoma cases showed higher cellularity, with large, irregular and atypical lymphoid cells, frequent necrotic cells in the background, and less pronounced neutrophil infiltration. Immunocytochemically, 11 of the 12 lymphoma cases were of the B-cell phenotype and the remaining case was of the T/NK-cell phenotype. In conclusion, careful cytopathological examination or immunocytochemistry of vitreous material facilitates appropriate diagnosis of intraocular lymphoma.

AimsThe cell block technique for assessing endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) specimens from pancreatic mucinous cystic lesions (MCLs) was systematically evaluated for the first time, including comparisons with three traditional methods of assessing such specimens.MethodsThe prospective arm comprised EUS-FNA specimens from EUS-suspected pancreatic MCLs. The retrospective arm comprised EUS-FNA specimens from pancreatic MCLs surgically resected before the study start. For each specimen, these data points were collected: macroscopic likelihood of mucin, cyst fluid carcinoembryonic antigen (CEA) level and presence of mucin in air-dried, direct smears and in cell block preparations.ResultsThe prospective and retrospective arms of the study comprised 80 and 30 EUS-FNA specimens, respectively. Seven prospective cases led to surgical resections during the study, and therefore, 37 EUS-FNA specimens were confirmed to have originated from MCLs. In the prospective arm, macroscopic mucin was suspected, cyst fluid CEA level exceeded 192 ng/mL, mucin was detected in direct smears and cell block preparations in 78%, 30%, 39% and 73% of cases, respectively. Of the 37 specimens confirmed to originate from MCLs, macroscopic mucin assessment, cyst fluid CEA level, direct smear mucin assessment and cell block mucin assessment had sensitivities for diagnosing MCL of 87%, 45%, 45% and 81%, respectively.ConclusionsCell block preparations are as likely to identify mucin from pancreatic MCLs as macroscopic assessment but are twice as likely to diagnose MCL than direct smears and fluid CEA biochemistry. The cell block technique is easy for sample collection and processing especially because these are identical for solid and cystic pancreatic lesions.

Serous cystadenoma (SCA) is an uncommon benign pancreatic neoplasm that is most often managed conservatively with follow-up rather than surgical excision. Therefore, to avoid the serious complications of pancreatic surgery, SCA should be diagnosed accurately at the preoperative level. Preoperative SCA diagnosis requires a multimodal diagnostic approach that includes imaging, cystic fluid biochemical analysis and/or endoscopic ultrasound fine-needle aspiration (EUS-FNA). In this brief report, we describe six EUS-FNA cases from five patients that were reported as "benign, consistent with serous cystadenoma". Samples were hypocellular, composed of loose clusters and single cuboidal, bland-looking cells among epithelial sheets representing gastrointestinal contamination. Cell blocks were prepared and all six FNA cases revealed cuboidal cells with a positive α-inhibin immunophenotype, consistent with a diagnosis of SCA. As EUS-FNAs of SCA commonly result in non-diagnostic interpretations, cell block preparations with subsequent immunochemistry can increase their diagnostic accuracy and guide patient management.