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Introduction: Pleuropulmonary blastoma (PPB) is a rare, aggressive, primary intrathoracic malignancy typically seen in infancy and early childhood. Accurate distinction from congenital cystic lung lesions is crucial due to significant prognostic and therapeutic differences. Cytologic features have rarely been described. Establishing a cytodiagnosis is challenging owing to its rarity, lack of awareness, and multiple morphologic mimics., Materials and Methods: This was a retrospective study conducted over 8 years. The histopathology and cytopathology databases were searched for all pediatric PPB cases. The corresponding cytologic samples were reviewed to identify characteristic features that can help distinguish PPB from its mimics., Results: There was a total of six cases of pediatric PPB reported during the study period. Of these, four (66.7%) presented as intrathoracic, and two (33.3%) as pleural-based masses. Cytology smears showed discretely scattered and perivascular arrangements of round-oval tumor cells with background eosinophilic stromal material. The tumor cells were mildly pleomorphic (n = 3) with round nuclei, fine chromatin, inconspicuous nucleoli, and scanty cytoplasm; however, three cases showed marked anaplasia, and one each showed necrosis and rhabdoid differentiation. On immunocytochemistry (4/6), these were positive for vimentin and desmin and negative for WT1, chromogranin, SALL4, cytokeratin, CD45, and CD99. FISH (1/6) did not show N-Myc amplification., Conclusions: Knowledge of the characteristic cytomorphological and immunocytochemical features of PPB is vital to establish a prompt and accurate cytodiagnosis with appropriate clinicoradiologic correlation., (© 2023 Wiley Periodicals LLC.)

Objectives: Pleural metastasis has extremely poor prognosis. Resection of pleural implants with infusion of intrathoracic hyperthermic chemotherapy may offer a survival advantage in selected patients. We evaluated the safety and efficacy of hyperthermic intrathoracic extracorporeal chemotherapy (HITEC) in patients who underwent pleurectomy/decortication (P/D) for secondary malignant pleural disease (SPD)., Methods: A total of 101 patients were evaluated over 72 months, with 35 patients electing to proceed with P/D and 60 minutes of HITEC with cisplatin at 42°C. Inclusion criteria were adults 18-79 years with unilateral pleural dissemination. Exclusion criteria were patients without control of primary site, extrathoracic metastatic disease, significant comorbidities, and a history of adverse reaction to cisplatin., Results: Median age was 56 years (36-73); 60% were women. SPD was thymoma in 13, breast cancer in 9, lung cancer in 6, colon cancer in 2, renal cell in 2, and esophageal, anal, and thymic cancers in one each. There was no operative mortality. Postoperative complications occurred in 18 patients (51%). No patient developed renal failure. Median follow-up was 24 months (4-60). The overall survival rate was 61%; 17 patients (49%) developed recurrent disease at a median of 12 months (6-36). There were no recurrences after 36 months Eleven patients (31%) died of metastatic disease at a median of 17 months (7-25)., Conclusions: Surgical cytoreduction of SPD followed by HITEC with cisplatin was well tolerated. No patient developed cisplatin-related toxicities. Long-term follow-up is warranted to determine survival advantage and refinement of inclusion criteria., (© 2023 Wiley Periodicals LLC.)

Immunotherapy with anti-PD1/PD-L1 is effective in only a subgroup of patients with malignant pleural mesothelioma (MPM). We investigated the efficacy of a combination of anti-PD1/PD-L1 and dendritic cell (DC) therapy to optimally induce effective anti-tumor immunity in MPM in both humans and mice. Data of nine MPM patients treated with DC therapy and sequential anti-PD1 treatment were collected and analyzed for progression-free survival (PFS) and overall survival (OS). Survival and T-cell responses were monitored in AC29 mesothelioma-bearing mice treated concurrently with the combination therapy; additionally, the role of the tumor-draining lymph node (TDLN) was investigated. The combination therapy resulted in a median OS and PFS of 17.7 and 8.0 months, respectively. Grade 3 to 4 treatment-related adverse events had not been reported. Survival of the mesothelioma-bearing mice treated with the combination therapy was longer than that of untreated mice, and coincided with improved T-cell activation in peripheral blood and less T-cell exhaustion in end stage tumors. Comparable results were obtained when solely the TDLN was targeted. We concluded that this combination therapy is safe and shows promising OS and PFS. The murine data support that PD-L1 treatment may reinvigorate the T-cell responses induced by DC therapy, which may primarily be the result of TDLN targeting., (© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer mainly caused by asbestos exposure. Specific and sensitive noninvasive biomarkers may facilitate and enhance screening programs for the early detection of cancer. We investigated DNA methylation (DNAm) profiles in MPM prediagnostic blood samples in a case-control study nested in the European Prospective Investigation into Cancer and nutrition (EPIC) cohort, aiming to characterise DNAm biomarkers associated with MPM. From the EPIC cohort, we included samples from 135 participants who developed MPM during 20 years of follow-up and from 135 matched, cancer-free, controls. For the discovery phase we selected EPIC participants who developed MPM within 5 years from enrolment (n = 36) with matched controls. We identified nine differentially methylated CpGs, selected by 10-fold cross-validation and correlation analyses: cg25755428 (MRI1), cg20389709 (KLF11), cg23870316, cg13862711 (LHX6), cg06417478 (HOOK2), cg00667948, cg01879420 (AMD1), cg25317025 (RPL17) and cg06205333 (RAP1A). Receiver operating characteristic (ROC) analysis showed that the model including baseline characteristics (age, sex and PC1wbc) along with the nine MPM-related CpGs has a better predictive value for MPM occurrence than the baseline model alone, maintaining some performance also at more than 5 years before diagnosis (area under the curve [AUC] < 5 years = 0.89; AUC 5-10 years = 0.80; AUC >10 years = 0.75; baseline AUC range = 0.63-0.67). DNAm changes as noninvasive biomarkers in prediagnostic blood samples of MPM cases were investigated for the first time. Their application can improve the identification of asbestos-exposed individuals at higher MPM risk to possibly adopt more intensive monitoring for early disease identification., (© 2022 UICC.)

Malignant pleural mesothelioma (MPM) is a rare but aggressive malignancy with a poor prognosis. Because of this tumor rarity and overlapping histologic features with other malignancy types, the histopathological findings and diagnostic immunohistochemical workup are essential in establishing the final diagnosis of MPMs. We aimed to review the diagnostic criteria, WHO tumor classification updates, and immunohistochemical staining markers diagnostic value to achieve an appropriate clinical diagnosis., (© 2022 The Authors. Diagnostic Cytopathology published by Wiley Periodicals LLC.)

The Hippo pathway effector YAP is dysregulated in malignant pleural mesothelioma (MPM). YAP's target genes include the secreted growth factor amphiregulin (AREG), which is overexpressed in a wide range of epithelial cancers and plays an elusive role in MPM. We assayed the expression of YAP and AREG in MPM pathology samples and that of AREG additionally in plasma samples of patients from the randomized phase 3 IFCT-0701 Mesothelioma Avastin Cisplatin Pemetrexed Study (MAPS) using immunohistochemistry and ELISA assays, respectively. MPM patients frequently presented high levels of tumor AREG (64.3%), a high cytosolic AREG expression being predictive of a better prognosis with longer median overall and progression-free survival. Surprisingly, tumor AREG cytosolic expression was not correlated with secreted plasma AREG. By investigating the AREG metabolism and function in MPM cell lines H2452, H2052, MSTO-211H and H28, in comparison with the T47D ER+ breast cancer cell line used as a positive control, we confirm that AREG is important for cell invasion, growth without anchorage, proliferation and apoptosis in mesothelioma cells. Yet, most of these MPM cell lines failed to correctly execute AREG posttranslational processing by metalloprotease ADAM17/tumor necrosis factor-alpha-converting enzyme (TACE) and extracell secretion. The favorable prognostic value of high cytosolic AREG expression in MPM patients could therefore be sustained by default AREG posttranslational processing and release. Thus, the determination of mesothelioma cell AREG content could be further investigated as a prognostic marker for MPM patients and used as a stratification factor in future clinical trials., (© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Embryonal rhabdomyosarcoma (ERMS) is a malignant small blue round cell tumor which is commonly seen in head and neck region. Breast and pleural involvement are uncommon. Rhabdomyosarcoma has been rarely reported in the body fluids like ascitic, pleural, and cerebrospinal fluid. In this article, we report an interesting case of ERMS which had deceptive small blue round cells in pleural fluid. The cytomorphological features along with a panel of immunocytochemical markers helped in arriving at the definite diagnosis. Later, biopsy from the breast lump and retroperitoneal mass also revealed the same tumor. This case is reported since it is rare to find sarcoma cells in pleural fluid and highlight the diagnostic difficulties faced during interpretation., (© 2020 Wiley Periodicals LLC.)

Malignant mesothelioma, a neoplasm arising within the serosal surfaces, has been linked closely to asbestos exposure. We present a case of 72-year-old male with a 27 year work-related history of asbestos exposure who presented with dyspnea. Chest computed tomography scan showed a large, right pleural effusion with compressive right lung atelectasis. Biopsies, subsequent pleurectomy and lung wedge resections revealed epithelioid malignant mesothelioma with associated focal non-keratinizing squamous-cell carcinoma, supported by extensive immunohistochemical stains and molecular studies. The patient was treated with 6 cycles of carboplatin/pemetrexed, showing no new metastases. Seven months post-treatment, the patient presented with progressive dyspnea and large pleural effusions. Bilateral pleural fluid was collected and showed malignant epithelioid cells, morphologically similar to the patient's pleural neoplastic cells. However, the tumor was positive for squamous cells markers and showed BAP1 loss, while negative for mesothelial markers. The findings support the diagnosis of squamous-cell carcinoma and were consistent with the patient's previously diagnosed pleural neoplastic origin. A malignant mesothelioma associated with squamous-cell carcinoma is a rare phenonmenon. To our knowledge, only two case reports are available in current literature. This unique case shows a single pleura tumor differentiating as both malignant mesothelioma and squamous-cell carcinoma. Squamous-cell carcinoma is the predominating malignancy seen within the bilateral pleural effusions, a potential pitfall for cytology specimen diagnosis., (© 2020 Wiley Periodicals LLC.)

Erythroblastic sarcoma (ES) is an extremely rare extramedullary solid tumor of immature erythroid cells, with around a dozen human cases to our knowledge presented so far in the english literature, none of the cases presenting as pleural effusion. Here we describe a case of ES in a thoracic wall diagnosed by cytological examination of pleural effusion with histologic correlation in a 53-year-old patient with a 10-month history of myelodysplastic syndrome/myeloproliferative neoplasm with grade III reticulin myelofibrosis., (© 2020 Wiley Periodicals LLC.)

Malignant pleural mesothelioma (MPM) is a tumor with high chemoresistance and poor prognosis. MPM-initiating cells (ICs) are known to be drug resistant, but it is unknown if and how stemness-related pathways determine chemoresistance. Moreover, there are no predictive markers of IC-associated chemoresistance. Aim of this work is to clarify if and by which mechanisms the chemoresistant phenotype of MPM IC was due to specific stemness-related pathways. We generated MPM IC from primary MPM samples and compared the gene expression and chemo-sensitivity profile of IC and differentiated/adherent cells (AC) of the same patient. Compared to AC, IC had upregulated the drug efflux transporter ABCB5 that determined resistance to cisplatin and pemetrexed. ABCB5-knocked-out (KO) IC clones were resensitized to the drugs in vitro and in patient-derived xenografts. ABCB5 was transcriptionally activated by the Wnt/GSK3β/β-catenin/c-myc axis that also increased IL-8 and IL-1β production. IL-8 and IL-1β-KO IC clones reduced the c-myc-driven transcription of ABCB5 and reacquired chemosensitivity. ABCB5-KO clones had lower IL-8 and IL-1β secretion, and c-myc transcriptional activity, suggesting that either Wnt/GSK3β/β-catenin and IL-8/IL-1β signaling drive c-myc-mediated transcription of ABCB5. ABCB5 correlated with lower time-to-progression and overall survival in MPM patients treated with cisplatin and pemetrexed. Our work identified multiple autocrine loops linking stemness pathways and resistance to cisplatin and pemetrexed in MPM IC. ABCB5 may represent a new target to chemosensitize MPM IC and a potential biomarker to predict the response to the first-line chemotherapy in MPM patients., (© 2019 UICC.)

Background and Objectives: Hyperthermic intrathoracic chemotherapy (HITOC) is used for the treatment of malignant pleural tumors. Although HITOC proved to be safe, postoperative renal failure due to nephrotoxicity of intrapleural cisplatin remains a concern., Methods: This single-center study was performed retrospectively in patients who underwent pleural tumor resection and HITOC between September 2008 and December 2018., Results: A total of 84 patients (female n = 33; 39.3%) with malignant pleural tumors underwent surgical cytoreduction with subsequent HITOC (60 minutes; 42°C). During the study period, we gradually increased the dosage of cisplatin (100-150 mg/m 2 BSA n = 36; 175 mg/m 2 BSA n = 2) and finally added doxorubicin (cisplatin 175 mg/m 2 BSA/doxorubicin 65 mg; n = 46). All patients had perioperative fluid balancing. The last 54 (64.3%) patients also received perioperative cytoprotection. Overall 29 patients (34.5%) experienced renal insufficiency. Despite higher cisplatin concentrations, patients with cytoprotection showed significantly lower postoperative serum creatinine levels after 1 week (P = .006) and at discharge (P = .020). Also, they showed less intermediate and severe renal insufficiencies (5.6% vs 13.3%)., Conclusions: Adequate perioperative fluid management and cytoprotection seem to be effective in protecting renal function. This allows the administration of higher intracavitary cisplatin doses without raising the rate of renal insufficiencies., (© 2019 Wiley Periodicals, Inc.)

Brahma (BRM), of the SWI/SNF complex, has two 6 to 7 bp insertion promoter polymorphisms (BRM-741/BRM-1321) that cause epigenetic BRM suppression, and are associated with risk of multiple cancers. BRM polymorphisms were genotyped in malignant pleural mesothelioma (MPM) cases and asbestos-exposed controls. Multivariable logistic regression (risk) and Cox regression (prognosis) were performed, including stratified analyses by smoking status to investigate the effect of polymorphisms on MPM risk and prognosis. Although there was no significant association overall between BRM-741/BRM-1321 and risk in patients with MPM, a differential effect by smoking status was observed (P-interaction < .001), where homozygous variants were protective (aOR of 0.18-0.28) in ever smokers, while never smokers had increased risk when carrying homozygous variants (aOR of 2.7-4.4). While there was no association between BRM polymorphisms and OS in ever-smokers, the aHR of carrying homozygous-variants of BRM-741, BRM-1321 or both were 4.0 to 8.6 in never-smokers when compared to wild-type carriers. Mechanistically, lower mRNA expression of BRM was associated with poorer general cancer prognosis. Electrophoretic mobility shift assays and chromatin immunoprecipitation experiments (ChIP) revealed high BRM insertion variant homology to MEF2 regulatory binding sites. ChIP experimentation confirmed MEF2 binding only occurs in the presence of insertion variants. DNA-affinity purification assays revealed YWHA scaffold proteins as vital to BRM mRNA expression. Never-smokers who carry BRM homozygous variants have an increased chance of developing MPM, which results in worse prognosis. In contrast, in ever-smokers, there may be a protective effect, with no difference in overall survival. Mechanisms for the interaction between BRM and smoking require further study., (© 2019 Wiley Periodicals, Inc.)

Objectives: Gold standard therapy for solitary fibrous tumour of the pleura is complete surgical resection. Aims of this retrospective study are to evaluate oncological and surgical outcomes and to verify the clinical reliability of prognostic scores presented in literature., Methods: Study population: 107 patients surgically treated between 1972 and 2018. Male/female ratio: 1/2.45; median age at surgery: 60 years (range, 19-80); peduncle lesions 69.8%; visceral pleura origin 72.9%; benign histology 73.8%; median diameter 8 cm (range 1 to 35, 27 cases giant [≥15 cm])., Results: After a median follow up of 7 years, 12 patients had recurrence. By multivariate analysis, malignant histology (P = .03; HR, 4.17; 95% CI, 1.15-15.06), origin from parietal pleura (P  = .03; HR, 3.90; 95% CI, 1.08-14.09), England (P = .002; HR, 1.98; 95% CI, 1.28-3.07), Diebold (P = .008; HR, 1.96; 95% CI, 1.20-3.22) and Tapias (P = .003; HR, 1.75; 95% CI, 1.20-2.53) scores were found independent significant predictors of relapse. Giant tumours were associated with open surgery (P = .003), origin from parietal pleura (P = .011) and intraoperative bleeding (P > .001). Overall 10-year disease-free survival (DFS) rate was 81%. Predictors of worst DFS were parietal pleura origin (P = .002), malignant histology (P = .006) and all the prognostic scores., Conclusions: Malignant histology and origin from parietal pleura were significant predictors of tumour recurrence and worst DFS. The use of current scoring systems can help to predict clinical behaviour. Patients with higher risk of relapse can benefit from closer follow up, prolonged over 10 years., (© 2019 Wiley Periodicals, Inc.)

Vascular-targeted low-dose photodynamic therapy (L-PDT) was shown to improve chemotherapy distribution in malignant pleural tumors such as malignant pleural mesothelioma (MPM). However, the mechanisms triggered by L-PDT on the tumor vasculature are still debated. In pericyte and endothelial cell co-cultures, we show that pericytes exhibit enhanced sensitivity towards L-PDT compared to endothelial cells, displaying actin stress fibers and cellular contraction via Rho/ROCK kinase signaling myosin light chain and focal adhesion kinase phosphorylation (MLC-P, FAK-P). We then confirm, in two separate MPM models, in mice the phosphorylation of the MLC in pericytes specifically following L-PDT. Furthermore, while L-PDT does not affect tumor vascular density or diameter, we show that it enhances tumor vascular pericyte coverage, leads to a drop in tumor interstitial fluid pressure and enhances the transport of FITC-dextran throughout tumors. In conclusion, L-PDT has the potential to stabilize the tumor vascular bed which improves vascular transport. The mechanism described in the present study may help translate and optimize this approach in patients. Lasers Surg. Med. 51:550-561, 2019. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

Image cytometry enables quantitative cell characterization with preserved tissue architecture; thus, it has been highlighted in the advancement of multiplex immunohistochemistry (IHC) and digital image analysis in the context of immune-based biomarker monitoring associated with cancer immunotherapy. However, one of the challenges in the current image cytometry methodology is a technical limitation in the segmentation of nuclei and cellular components particularly in heterogeneously stained cancer tissue images. To improve the detection and specificity of single-cell segmentation in hematoxylin-stained images (which can be utilized for recently reported 12-biomarker chromogenic sequential multiplex IHC), we adapted a segmentation algorithm previously developed for hematoxlin and eosin-stained images, where morphological features are extracted based on Gabor-filtering, followed by stacking of image pixels into n-dimensional feature space and unsupervised clustering of individual pixels. Our proposed method showed improved sensitivity and specificity in comparison with standard segmentation methods. Replacing previously proposed methods with our method in multiplex IHC/image cytometry analysis, we observed higher detection of cell lineages including relatively rare T H 17 cells, further enabling sub-population analysis into T H 1-like and T H 2-like phenotypes based on T-bet and GATA3 expression. Interestingly, predominance of T H 2-like T H 17 cells was associated with human papilloma virus (HPV)-negative status of oropharyngeal squamous cell carcinoma of head and neck, known as a poor-prognostic subtype in comparison with HPV-positive status. Furthermore, T H 2-like T H 17 cells in HPV-negative head and neck cancer tissues were spatiotemporally correlated with CD66b + granulocytes, presumably associated with an immunosuppressive microenvironment. Our cell segmentation method for multiplex IHC/image cytometry potentially contributes to in-depth immune profiling and spatial association, leading to further tissue-based biomarker exploration. © 2019 International Society for Advancement of Cytometry., (© 2019 International Society for Advancement of Cytometry.)

Malignant mesothelioma (MM) is a therapy-resistant cancer arising primarily from the lining of the pleural and peritoneal cavities. The most frequently altered genes in human MM are cyclin-dependent kinase inhibitor 2A (CDKN2A), which encodes components of the p53 (p14ARF) and RB (p16INK4A) pathways, BRCA1-associated protein 1 (BAP1), and neurofibromatosis 2 (NF2). Furthermore, the p53 gene (TP53) itself is mutated in ~15% of MMs. In many MMs, the PI3K-PTEN-AKT-mTOR signaling node is hyperactivated, which contributes to tumor cell survival and therapeutic resistance. Here, we demonstrate that the inactivation of both Tp53 and Pten in the mouse mesothelium is sufficient to rapidly drive aggressive MMs. Pten L/L ;Tp53 L/L mice injected intraperitoneally or intrapleurally with adenovirus-expressing Cre recombinase developed high rates of peritoneal and pleural MMs (92% of mice with a median latency of 9.4 weeks and 56% of mice with a median latency of 19.3 weeks, respectively). MM cells from these mice showed consistent activation of Akt-mTor signaling, chromosome breakage or aneuploidy, and upregulation of Myc; occasional downregulation of Bap1 was also observed. Collectively, these findings suggest that when Pten and Tp53 are lost in combination in mesothelial cells, DNA damage is not adequately repaired and genomic instability is widespread, whereas the activation of Akt due to Pten loss protects genomically damaged cells from apoptosis, thereby increasing the likelihood of tumor formation. Additionally, the mining of an online dataset (The Cancer Genome Atlas) revealed codeletions of PTEN and TP53 and/or CDKN2A/p14ARF in ~25% of human MMs, indicating that cooperative losses of these genes contribute to the development of a significant proportion of these aggressive neoplasms and suggesting key target pathways for therapeutic intervention., (© 2018 Wiley Periodicals, Inc.)

Because most of malignant pleural mesothelioma (MPM) patients first present with pleural effusion, detection of mesothelioma cells on effusion smears is critical for early diagnosis. Recently, accumulating evidence indicating that the cytological diagnosis of MPM supported by ancillary techniques is as reliable as that based on histopathology has led to new guidelines for the cytopathologic diagnosis of MPM. Based on the guidelines, a combination of cytomorphological criteria and verification by ancillary techniques is required for the cytologic diagnosis of MPM. Detection of p16 homozygous deletion by fluorescence in situ hybridization (FISH) is the most reliable ancillary technique for differentiating MPM from reactive mesothelial cells (RMC) because of its relatively high sensitivity and extremely high specificity. We showed that the p16 deletion status of MPM cells in pleural effusions reflected that of the underlying invasive MPM tissues, indicating the usefulness of p16 FISH in effusion smear cytology for MPM diagnosis. Thus, for differentiating MPM from RMC, we propose to perform p16 FISH as often as possible. A positive p16 homozygous deletion supports the diagnosis of MPM. However, a negative result does not rule out the possibility of MPM. In such cases, a morphological assessment is critical. Therefore, we analyzed the morphological characteristics of p16 deletion-positive mesothelioma cells using a combination of virtual microscopy and p16 FISH, and identified three morphological characteristics useful for the differentiation, including cell-in-cell engulfment with or without hump formation, multinucleate cells, and larger berry-like cell aggregates. Diagn. Cytopathol. 2016;44:774-780. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Malignant melanoma is one of the most aggressive and treatment resistant skin cancers. India enjoys a low incidence of melanoma, and age specific incidence rates for cutaneous malignant melanoma (CMM) are being less than 0.5 per 1,000,000. This could be due to under-reporting of melanoma on account of a low index of suspicion by clinicians and pathologists alike. Most common site for origin of primary melanoma is skin, accounting for about 91.2% of all reported primary malignant melanoma cases. Other primary sites are relatively uncommon. Primary pleural melanoma is a very rare tumor and to the best of our knowledge, only seven cases have been reported so far worldwide. We hereby discuss a new case, only second from India. Our patient also had coexistent congenital hairy nevus, an unusual association also noted in two previously reported cases. Excluding primary cutaneous melanoma with pleural metastasis was a diagnostic challenge in this case but multiple cutaneous biopsies together with clinical and findings helped us arrive at this unusual diagnosis. Unfortunately, the patient succumbed to his illness. Diagn. Cytopathol. 2016;44:648-652. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Background: Mesothelioma patients often present with serosal effusions, which are ideal for cytopathological diagnoses. However, the morphological overlap between malignant and benign mesothelial proliferation can make a conclusive cytological diagnosis of mesothelioma elusive because immunohistochemical staining does not discriminate definitively between the two in this setting. p16 is deleted in up to 80% of pleural mesotheliomas. The aim of this study was to establish the correlation between the p16 deletion status of the cell block with that of its corresponding tumor using fluorescence in situ hybridization (FISH) analysis for individual patient tumors., Methods: Twenty-two biopsies and 24 corresponding cell blocks, containing serosal effusions with atypical mesothelial cells from 22 patients with histologically confirmed pleural mesotheliomas, were analyzed with p16 FISH. Seventeen cell blocks consisting of serosal effusions with reactive mesothelial cells from nonmesothelioma cases were also analyzed. Combined immunofluorescence and FISH were also performed., Results: Seventeen of the 22 mesothelioma patients (77.3%) showed homozygous deletions of p16 in the tumor tissue and in the atypical mesothelial cells from the cell blocks. p16 FISH followed by immunofluorescence with EMA was helpful towards identifying the mesothelioma cells in the cell blocks., Conclusion: We confirmed that the p16 FISH results obtained from the cell blocks are as reliable as those from the tissue sections. Cell block analysis is recommended for patients with serosal effusions of unknown origins with the following methods: immunohistochemistry should be performed to validate the mesothelial origin, and p16 FISH should be performed to confirm malignancy. Diagn. Cytopathol. 2016;44:591-598. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Extramedullary hematopoiesis (EMH) represents the presence of immature hematopoietic elements and their differentiation into mature blood components outside of the medullary bone and may be seen in a variety of circumstances in the postnatal period, but is most strongly associated with disorders of the hematopoietic system. Postnatally, EMH is typically identified at sites of fetal hematopoiesis, the spleen, and liver, but occasional reports have identified it in nearly every tissue of the body. We report a case of EMH presenting as pleural mass, initially suspected to represent a neoplastic process in a patient with multiple comorbidities, including history of carcinoma, but without co-existing hematologic disorder. On-site evaluation of the fine-needle aspiration specimen was initially suspicious for a malignant neoplasm, but further evaluation revealed the lesion to be a mass forming focus of non-hepatosplenic EMH. In the era of increasing utilization of imaging, mass forming EMH is increasingly detected. When unsuspected, EMH may present a diagnostic challenge for the pathologist and may be confused for a neoplastic process., (© 2015 Wiley Periodicals, Inc.)

We report a rare case of a 45-year-old African American woman with Neuroblastoma-like Schwannoma (Neurilemmoma) occurring in the posterior mediastinum as a pleural-based mass noted on computed tomography (CT) scan. A CT-guided core biopsy of the mass was performed and core biopsy imprints were prepared during the procedure. A Diff-Quik stain was performed for on-site evaluation of specimen adequacy. The hematoxylin and eosin (H&E) staining was evaluated subsequently. Immunohistochemistry panels were applied to the same specimen. The cytologic findings of the core biopsy imprints showed hypercellular smears with a predominance of small cells with atypical features including hyperchromatic, round nuclei and occasional nucleoli. Neurocytic rosettes were particularly appreciated on H&E stain. The immunohistochemical results exhibited strong and diffuse immunoreactivity for S-100 and vimentin. This case enriches the cytopathology literature by providing awareness of this tumor presenting as a posterior mediastinal mass., (© 2015 Wiley Periodicals, Inc.)

Malignant mesothelioma (MM) is an aggressive cancer of mesothelial cells of pleural and peritoneal cavities. In 85% of cases both pleural and peritoneal MM is caused by asbestos exposure. Although both are asbestos-induced cancers, the incidence of pleural MM is significantly higher (85%) than peritoneal MM (15%). It has been proposed that carcinogenesis is a result of asbestos-induced inflammation but it is not clear what contributes to the differences observed between incidences of these two cancers. We hypothesize that the observed differences in incidences of pleural and peritoneal MM are the result of differences in the direct response of these cell types to asbestos rather than to differences mediated by the in vivo microenvironment. To test this hypothesis we characterized cellular responses to asbestos in a controlled environment. We found significantly greater changes in genome-wide expression in response to asbestos exposure in pleural mesothelial cells as compared to peritoneal mesothelial cells. In particular, a greater response in many common genes (IL-8, ATF3, CXCL2, CXCL3, IL-6, GOS2) was seen in pleural mesothelial cells as compared to peritoneal mesothelial cells. Unique genes expressed in pleural mesothelial cells were mainly pro-inflammatory (G-CSF, IL-1β, IL-1α, GREM1) and have previously been shown to be involved in development of MM. Our results are consistent with the hypothesis that differences in incidences of pleural and peritoneal MM upon exposure to asbestos are the result of differences in mesothelial cell physiology that lead to differences in the inflammatory response, which leads to cancer., (© 2015 Wiley Periodicals, Inc.)

We report a very unusual cytologic feature, intranuclear inclusion bodies, in mesothelioma of a predominantly adenomatoid type. The patient, a 57-year-old woman, was presented with dyspnea and right pleural effusion. Pleural aspiration cytology revealed many cohesive ball-like clusters, with a tubular pattern, composed of small atypical cells displaying a high-nuclear-cytoplasmic ratio. They had a nuclear groove and irregular intranuclear inclusion bodies. Right lung partial resection with thoracoscopy revealed that a white tumor had proliferated along the pleural surface at S(8) . Histology revealed nodular tumor cells forming dilated structures mixed with small tubular or glandular structures similar to those seen in benign adenomatoid tumors. These tumor cells had invaded peripheral lung tissues. Such inclusion bodies have not been reported earlier in mesothelioma. On the basis of this observation, we propose that the adenomatoid type of malignant mesothelioma be added to the differential diagnosis of malignant effusions when tumor cells with nuclear grooves and intranuclear inclusions are found in pleural aspiration cytology., (Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.)

Malignant mesothelioma (MM) are highly aggressive asbestos-related neoplasms, which show strong chemotherapy resistance, and there is no effective cure for MM so far. Calretinin (CR) is widely used as a diagnostic marker for epithelioid and mixed (biphasic) mesothelioma; however, little is known about CR's putative functions in tumorigenesis. CR protects against asbestos-induced acute cytotoxicity mediated by the AKT/PI3K pathway, and furthermore, SV40 early region genes are able to upregulate CR in mesothelial cells. However, the precise role of CR in mesothelioma is still unknown. Downregulation of CR via lentiviral-mediated short-hairpin RNA significantly decreased the viability and proliferation of mesothelioma cells in vitro. The effect was strong in epithelioid-dominated cell lines (ZL55 and MSTO-211H). A weaker and delayed effect was observed in mesothelioma cells with prevalent sarcomatoid morphology (SPC111, SPC212 and ZL34). The specificity of the effect was confirmed by stable enhanced green fluorescent protein-CR expression in mesothelioma cell lines and subsequent downregulation. Depletion of CR led these cancer cell lines to enter apoptosis within 72 hr postinfection via strong activation of the intrinsic caspase 9-dependent pathway. Downregulation of CR in immortalized mesothelial cells LP9/TERT-1 strongly blocked proliferation and caused a G1 block without decreasing viability or activating apoptosis pathways. These results demonstrate that downregulation of CR had a strong effect on the viability of MM cells and that CR is essential for cells derived from MM. The authors anticipate these findings to reveal CR as a highly interesting new putative therapeutic target for mesothelioma treatment of especially the epithelioid, as well as of the mixed and sarcomatoid type., (© 2013 UICC.)

Occupational asbestos exposure is believed to be the primary etiologic link to mesothelioma. However, in the evaluation of familial mesothelioma, it is important to consider the possibility of household exposure to asbestos. In this study, we report a family in which the father with prolonged occupational asbestos exposure developed malignant pleural mesothelioma and his daughter 14 years later mesothelioma in situ with focally early invasion. Several reports of familial aggregations of mesothelioma strongly support that genetic factors in collaboration with environmental exposure may contribute etiologically to an as yet unknown fraction of occurrence of this disease., (Copyright © 2012 Wiley Periodicals, Inc.)

Lymphohistiocytoid malignant mesothelioma is an infrequent variant of sarcomatoid mesothelioma representing approximately 0.5-3.3% of malignant mesotheliomas. It has been related to asbestos exposure. The tumor is characterized by a diffuse large histiocyte-like cells proliferation mixed with an inflammatory infiltrate of lymphocytes and plasma cells. Its cytological diagnosis is difficult. We present a case of a 67-year-old female with lymphohistiocytoid mesothelioma involving the left pleura. The cytological, histological, and immunohistochemical features are discussed., (Copyright © 2011 Wiley Periodicals, Inc.)

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis for which an effective therapy remains to be established. This study investigated the therapeutic potential of gene delivery using suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of intracellular signaling pathways, for the treatment of MPM. We infected MPM cells (MESO-4, H28 and H226) with adenovirus-expressing SOCS-1 vector to examine the effect of SOCS-1 overexpression on MPM cells. We evaluated the antitumor effect of SOCS-1 gene delivery combined with cisplatin plus pemetrexed by cell proliferation, apoptosis and invasion assay. We also investigated the regulation of NF-κB and STAT3 signaling related to apoptotic pathways. Furthermore, we evaluated the inhibition of tumor growth by SOCS-1 gene delivery combined with cisplatin plus pemetrexed in vivo. SOCS-1 gene delivery cooperated with cisplatin plus pemetrexed to inhibit cell proliferation, invasiveness and induction of apoptosis in MPM cells. SOCS-1 regulated NF-κB and STAT3 signaling to induce apoptosis in MESO-4 and H226 cells. Furthermore, SOCS-1 gene delivery cooperated with cisplatin plus pemetrexed to regulate NF-κB signaling and significantly inhibit tumor growth of MPM in vivo. These results suggest that SOCS-1 gene delivery has a potent antitumor effect against MPM and a potential for clinical use in combination with cisplatin plus pemetrexed., (Copyright © 2012 UICC.)

Malignant pleural mesothelioma (MPM) is a highly aggressive neoplasm arising from the mesothelial cells lining the parietal pleura and it exhibits poor prognosis. Although there has been significant progress in MPM treatment, development of more efficient therapeutic approaches is needed. BMAL1 is a core component of the circadian clock machinery and its constitutive overexpression in MPM has been reported. Here, we demonstrate that BMAL1 may serve as a molecular target for MPM. The majority of MPM cell lines and a subset of MPM clinical specimens expressed higher levels of BMAL1 compared to a nontumorigenic mesothelial cell line (MeT-5A) and normal parietal pleural specimens, respectively. A serum shock induced a rhythmical BMAL1 expression change in MeT-5A but not in ACC-MESO-1, suggesting that the circadian rhythm pathway is deregulated in MPM cells. BMAL1 knockdown suppressed proliferation and anchorage-dependent and independent clonal growth in two MPM cell lines (ACC-MESO-1 and H290) but not in MeT-5A. Notably, BMAL1 depletion resulted in cell cycle disruption with a substantial increase in apoptotic and polyploidy cell population in association with downregulation of Wee1, cyclin B and p21(WAF1/CIP1) and upregulation of cyclin E expression. BMAL1 knockdown induced mitotic catastrophe as denoted by disruption of cell cycle regulators and induction of drastic morphological changes including micronucleation and multiple nuclei in ACC-MESO-1 cells that expressed the highest level of BMAL1. Taken together, these findings indicate that BMAL1 has a critical role in MPM and could serve as an attractive therapeutic target for MPM., (Copyright © 2012 UICC.)

Ovarian tumors of sex-cord stromal derivation rarely exfoliate malignant cells in serous effusions. Adult granulosa cell tumor (AGCT) often presents as a stage I disease and association with ascites is about 10%. AGCT is rarely known to exfoliate tumor cells in the ascitic fluid. Exfoliation of malignant cells in the pleural fluid is rarer and has not been described previously in literature to the best of our knowledge. We report a case of AGCT presenting as stage IV disease with exfoliation of malignant cells in the pleural and ascitic fluid with exudative effusions. We wish to emphasize on cytomorphologic features of AGCT to differentiate the same from malignant epithelial tumors. A precise diagnosis in such a case may be possible on serous body fluid cytology with a combined clinical and cytopathologic approach., (Copyright © 2011 Wiley Periodicals, Inc.)

Due to the large scale use of asbestos (more than 3.5 million tons produced or imported until its definitive banning in 1992), a specific national surveillance system of mesothelioma incident cases is active in Italy, with direct and individual anamnestic etiological investigation. In the period between 1993 and 2004, a case-list of 8,868 pleural MM was recorded by the Italian National Register (ReNaM) and the modalities of exposure to asbestos fibres have been investigated for 6,603 of them. Standardized incidence rates are 3.49 (per 100,000 inhabitants) for men and 1.25 for women, with a wide regional variability. Occupational asbestos exposure was in 69.3% of interviewed subjects (N = 4,577 cases), while 4.4% was due to cohabitation with someone (generally, the husband) occupationally exposed, 4.7% by environmental exposure from living near a contamination source and 1.6% during a leisure activity. In the male group, 81.5% of interviewed subjects exhibit an occupational exposure. In the exposed workers, the median year of first exposure was 1957, and mean latency was 43.7 years. The analysis of exposures by industrial sector focuses on a decreasing trend for those traditionally signaled as "at risk" (asbestos-cement industry, shipbuilding and repair and railway carriages maintenance) and an increasing trend for the building construction sector. The systematic mesothelioma surveillance system is relevant for the prevention of the disease and for supporting an efficient compensation system. The existing experience on all-too-predictable asbestos effects should be transferred to developing countries where asbestos use is spreading., (Copyright © 2011 UICC.)

Background: To evaluate epidermal growth factor receptor (EGFR) phenotypic expression and related gene status in malignant pleural mesothelioma (MPM) and to correlate the results with patients' prognosis., Method: Eighty-three cases of MPM specimens were submitted to immunohistochemical (IHC) staining to evaluate the expression of EGFR protein; positive cases were submitted to fluorescence in situ hybridization (FISH) to investigate the gene status. Results were correlated with clinico-pathological characteristics and long-term survival., Results: Thirty-eight cases (46%) demonstrated a positive IHC reaction [30/57 (52%) epithelial and 8/20 (40%) biphasic whereas sarcomatous MPM were negative]. No association was recorded between EGFR IHC positive staining and age, gender, or asbestos exposure. Three out of 38 (8%) cases submitted to FISH were positive revealing gene amplification or polysomy. Mean follow-up was 15.4  months (range 2-44). Epithelial subtype only was confirmed to affect prognosis (2-years survival rate 40 vs. 18% for non-epithelial subtype, P = 0.042). When epithelial MPM patients were considered, IHC EGFR positive staining was demonstrated to be a negative prognostic factor (2-years survival rate 26 vs. 60% for IHC EGFR negative staining; P = 0.026)., Conclusions: EGFR overexpression is identified by IHC in 52% of epithelial MPM and is demonstrated to be a factor negatively affecting prognosis. Phenotypic overexpression seems not to be related to gene status alteration., (Copyright © 2011 Wiley Periodicals, Inc.)

Members of the extracellular signal-regulated kinase (ERK) family may have distinct roles in the development of cell injury and repair, differentiation and carcinogenesis. Here, we show, using a synthetic small-molecule MEK1/2 inhibitor (U0126) and RNA silencing of ERK1 and 2, comparatively, that ERK2 is critical to transformation and homeostasis of human epithelioid malignant mesotheliomas (MMs), asbestos-induced tumors with a poor prognosis. Although MM cell (HMESO) lines stably transfected with shERK1 or shERK2 both exhibited significant decreases in cell proliferation in vitro, injection of shERK2 cells, and not shERK1 cells, into immunocompromised severe combined immunodeficiency (SCID) mice showed significant attenuated tumor growth in comparison to shControl (shCon) cells. Inhibition of migration, invasion and colony formation occurred in shERK2 MM cells in vitro, suggesting multiple roles of ERK2 in neoplasia. Microarray and quantitative real-time PCR analyses revealed gene expression that was significantly increased (CASP1, TRAF1 and FAS) or decreased (SEMA3E, RPS6KA2, EGF and BCL2L1) in shERK2-transfected MM cells in contrast to shCon-transfected MM cells. Most striking decreases were observed in mRNA levels of Semaphorin 3 (SEMA3E), a candidate tumor suppressor gene linked to inhibition of angiogenesis. These studies demonstrate a key role of ERK2 in novel gene expression critical to the development of epithelioid MMs. After injection of sarcomatoid human MM (PPMMill) cells into SCID mice, both shERK1 and shERK2 lines showed significant decreased tumor growth, suggesting heterogeneous effects of ERKs in individual MMs., (Copyright © 2010 UICC.)

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis for which an effective therapy remains to be established. Our study investigated the therapeutic potential of the suppressor of cytokine signaling 3 (SOCS3), an endogenous inhibitor of intracellular signaling pathways, for treatment of MPM. We infected MPM cells (H226, EHMES-1, MESO-1 and MESO-4) with an adenovirus-expressing SOCS3 (AdSOCS3) to examine the effect of SOCS3 overexpression on MPM cells. SOCS3 overexpression reduced MPM proliferation and induced apoptosis and partial G0/G1 arrest. SOCS3 also inhibited the proliferation of MPM cells via multiple signaling pathways including Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated kinase (ERK), focal adhesion kinase (FAK) and p53 pathways. Notably, AdSOCS3 treatment inhibited tumor growth in an MPM pleural xenograft model. These findings demonstrate that overexpression of SOCS3 has a potent antitumor effect against MPM both in vitro and in vivo and indicate the potential for clinical use of SOCS3 for MPM treatment., (Copyright © 2010 UICC.)

Pleural malignant mesothelioma (MM), which is an aggressive neoplasm with a high mortality, frequently manifests initially as pleural effusions. The sensitivity of cytologic examination for its diagnosis varies widely in literature and most of the figures are from earlier studies with conventional cytologic preparations. The objective of this study was to provide the current evidence on the role and sensitivity of cytologic examination of pleural fluid in the diagnosis of MM. We reviewed the cytologic findings in pleural effusions of a large series of histologically proven MM (234 cases) diagnosed in our institution between 2001 and 2008. Of all cases, 154 (66%) had cytologic material examined. A specific diagnosis of MM was rendered or suspected in 53% (79 patients). The lowest sensitivity (20%) was noticed in sarcomatoid MM cases. MM was favored over adenocarcinoma in 97% of patients with positive cytologic findings that have been confirmed with immunohistochemistry. In this series, five cases were inadequate and five cases were initially reported as atypical, whereas 65 cases (44%) were reported as negative for malignancy. On review of the cytology slides, only four cases were upgraded from benign to suspicious compared to four cases downgraded from suspicious to atypical but no significant improvement to the diagnosis could be made on revision. These data suggested that a cytologic diagnosis contributed useful information in patients with epithelioid and biphasic pleural MM. Limitations of the cytologic examination of MM should also be acknowledged., (Copyright © 2010 Wiley-Liss, Inc.)

NK4 exhibits two distinct biological actions: antagonistic inhibition of hepatocyte growth factor (HGF) through binding to the Met/HGF receptor, and antiangiogenic action through binding to perlecan. Here, the anti-tumor effect of NK4 on malignant pleural mesothelioma was investigated. Of the 7 human malignant mesothelioma cell lines (ACC-Meso-1, ACC-Meso-4, EHMES-1, EHMES-10, H28, H2052 and JMN-1B), only EHMES-10 cells formed subcutaneous tumors when implanted into mice. For EHMES-10 cells, HGF facilitated invasion of the cells in collagen gel, whereas NK4 and neutralizing anti-HGF antibody suppressed the HGF-induced invasion. In addition, NK4 but not anti-HGF antibody suppressed proliferation of EHMES-10 cells in collagen, suggesting that the suppression by NK4 was independent of the HGF-Met pathway. In the subcutaneous tumor model, recombinant adenovirus-mediated intratumoral expression of NK4 inhibited tumor growth, while the invasive characteristic of tumor cells was not observed. Analysis of Met receptor tyrosine phosphorylation, proliferation, apoptosis and blood vessels in the tumor tissues indicated that the inhibitory effect of NK4 expression might be primarily caused by the inhibition of tumor angiogenesis. In all the 7 mesothelioma lines, HGF stimulated Met tyrosine phosphorylation, and this was associated with enhanced cell migration. HGF-dependent Met activation and migration were inhibited by NK4. Since malignant pleural mesothelioma represents an aggressive neoplasm characterized by extensive invasive growth, suppression of invasive growth has therapeutic value. Thus, the simultaneous inhibition of the HGF-Met pathway and angiogenesis by NK4 for treatment of malignant pleural mesothelioma is significant, particularly to attenuate migration and invasive growth.

Human malignant pleural mesothelioma (HMPM) is an aggressive neoplasm that is highly resistant to conventional therapies. We established 3 HMPM cell lines (TCC-MESO-1, TCC-MESO-2 and TCC-MESO-3) from Japanese patients; the first 2 from the primary and metastatic tumors of a patient with the epithelioid type of HMPM, and the third from a patient with biphasic characteristics of the tumor (epithelioid and sarcomatous phenotypes). The 3 cell lines resembled the original HMPMs in their morphological and biological features, including the genetic alterations such as lack of p16 expression and mutation of p53. Their tumorigenicity was determined in SCID mice by orthotopic implantation (20-46%). The tumorigenicity of the HMPM cell lines, which was relatively low, was enhanced by repeated subcultures and orthotopic implantations, and 3 competent tumorigenic sublines were produced (Me1Tu, Me2Tu and Me3Tu sublines from the TCC-MESO-1, TCC-MESO-2 and TCC-MESO-3 cell lines, respectively). The resultant HMPM sublines efficiently generated tumors in the SCID mice (100%) following orthotopic implantation. SCID mice implanted with the competent sublines, into one of which the luciferase gene was introduced, displayed quantitative fluctuation of the bioluminescence for the tumor volume in vivo. Oral administration of S-1, an anticancer agent, suppressed the proliferation of the luciferase gene-expressing Me1Tu subline in the mouse models in vivo, with a treated-to-control ratio of the mean tumor volume of 0.2. The orthotopic implantation mouse model proved to be useful for quantitative evaluation of the efficacy of novel anticancer drugs and also for studying the biology of HMPMs in vivo.

Regional specificity of lung tumor formation has rarely been studied in mouse or human. By using crosses of strains semi-congenic for lung cancer susceptibility locus Sluc20, we have analyzed the genetic influences of Sluc20 and 5 other loci on tumor regionality in the mouse lung. We have mapped Sluc20 to a 27.92-MB proximal region of chromosome 8 and found that it controls the number and load of only those tumors that surround or are directly adjacent to the bronchi or bronchioli (peribronchial tumors). These tumors lie outside the bronchial basement membrane and tend to reach a larger size than the tumors at other locations in the lung. Similar to tumors of alveolar lineage at other locations, peribronchial tumors stain with SP-C but not CC10 antibody. The effects of Sluc20 alleles are additive because the number of peribronchial tumors in heterozygotes is intermediate. These findings show that tumor regionality in the mouse lung, which represents a novel level of lung tumor heterogeneity, is under specific genetic control. The identification of genes controlling lung tumor regionality will provide novel insights into the biology of lung tumors and potentially improve the possibilities of individualized prognosis and treatment in human lung cancer.

The aim of this study was to evaluate whether immunocytochemical expressions of proliferation markers, such as minichromosome maintenance protein 7 (MCM 7), topoisomerase IIalpha (topo IIalpha), and Ki-67, in reactive mesothelial cells and malignant cells obtained from cavital fluids could be useful for their differential diagnosis. Samples diagnosed as reactive mesothelial cells (14 cases) or malignant tumors (28 cases) in cavital fluids were examined. Immunocytochemical staining of MCM 7, topo IIalpha, and Ki-67 was performed with the universal immunoperoxidase polymer method. In reactive mesothelial cells, MCM 7 was stained in a fine granular pattern and its distribution was uniform in the nuclei. Topo IIalpha and Ki-67 were stained in a coarse granular pattern and the distributions were the same as MCM 7. In contrast, in malignant cells, MCM 7 was stained in an irregular and fine granular pattern, and topo IIalpha and Ki-67 were stained in a uniform and coarse granular pattern. Labeling indices of MCM 7 (cut-off value; 30%, sensitivity; 100%, and specificity; 100%), topo IIalpha (cut-off value; 15%, sensitivity; 89.3%, and specificity; 92.9%) and Ki-67 (cut-off value; 30%, sensitivity; 64.3%, and specificity; 92.9%) of malignant cells were significantly higher than those of reactive mesothelial cells. MCM 7, topo IIalpha, and Ki-67 are different types of cell proliferation markers. MCM 7 and topo IIalpha, in particular, could be reliable tools for differential diagnosis between reactive mesothelial cells and malignant cells.

There is no established methodology to help select cost effective antibody panels. We used Bayesian statistics and an evidence-based pathology (EBP) approach to retrospectively review the use of immunohistochemistry (IHC) in 153 consecutive pleural effusions evaluated in our laboratory from 2005-2007 for the differential diagnosis of malignant mesothelial cells versus carcinoma cells and to estimate the likely site of origin of a carcinoma. The results in this "training" set were used to design antibody panels and test their clinical applicability on a "test set" of 44 pleural effusions collected in early 2008. Cytopathologists had used 6 +/- 4.5 IHC tests per case for the diagnosis of malignant mesothelioma (n = 9) and carcinomas of lung (n = 60), breast (n = 47), Müllerian (n = 25), and other origins in the "training set". The sensitivity and specificity of pleural cytology using all these IHC tests were 32% and 95%, respectively. Sensitivity, specificity and post-test odds (PTO) of a positive IHC result were calculated for each antibody and by the following classes: malignant mesothelial cells and carcinoma cells by primary site of origin. The antibodies that provided the best PTO to diagnose the most prevalent tumors in our population were included in diagnostic panels for male (calretinin, TTF-1, PSA and CDX-2) and female (calretinin, TTF-1, ER and CA125) patients. These panels provided 100% specificity and 77% and 50% sensitivity, respectively, for the pleural effusions from female and male patients in the "test set." The use of an EBP approach for test selection in cytopathology is discussed., ((c) 2009 Wiley-Liss, Inc.)

Background: Extrapleural pneumonectomy for malignant pleural mesothelioma is considered an aggressive procedure, but symptomatic and quality of life changes are unknown., Methods: Between 1997 and 2004, 16 consecutive patients underwent extrapleural pneumonectomy for mesothelioma followed by chemo-radiotherapy. Tumor-related symptoms and quality of life (Short-Form-36 and St. George's questionnaires) were assessed pre, 3, 6, 12, and 24 months postoperatively., Results: Thirty-day postoperative major morbidity was 31% with no mortality. At 3 months postoperatively, dyspnea improved in 10 patients (62%), pain in 12 (75%), cough in 10 (62%), fever in 11 (68%), Karnofsky-index in 10 (62%), Short-Form-36 physical-component-summary in 8, mental-component-summary in 5 and total St. George score in 8 (50%). At 1 year 10 (62%) patients were alive and majority of improved parameters were still stable. Thereafter they usually started to decline. Survival was influenced by nonepithelial histology (P < 0.01) and N2-disease (P < 0.01), which showed to be the only prognosticator at Cox regression (P < 0.0001, Odd ratio 5.4). Among symptomatic variables, a 3-month postoperative Short-Form-36 physical-component-summary above the median value correlated significantly with a better prognosis (P < 0.02)., Conclusions: Extrapleural pneumonectomy may rapidly improve symptoms as well as quality of life, especially in physical domains. Other than biological factors, postoperative Short-Form-36 physical component as well, significantly influenced the prognosis.

Pleural malignant mesothelioma (MM) is an aggressive cancer with a very long latency and a very short median survival. Little is known about the genetic events that trigger MM and their relation to poor outcome. The goal of our study was to characterize major genomic gains and losses associated with MM origin and progression and assess their clinical significance. We performed Representative Oligonucleotide Microarray Analysis (ROMA) on DNA isolated from tumors of 22 patients who recurred at variable interval with the disease after surgery. The total number of copy number alterations (CNA) and frequent imbalances for patients with short time (<12 months from surgery) and long time to recurrence were recorded and mapped using the Analysis of Copy Errors algorithm. We report a profound increase in CNA in the short-time recurrence group with most chromosomes affected, which can be explained by chromosomal instability associated with MM. Deletions in chromosomes 22q12.2, 19q13.32 and 17p13.1 appeared to be the most frequent events (55-74%) shared between MM patients followed by deletions in 1p, 9p, 9q, 4p, 3p and gains in 5p, 18q, 8q and 17q (23-55%). Deletions in 9p21.3 encompassing CDKN2A/ARF and CDKN2B were characterized as specific for the short-term recurrence group. Analysis of the minimal common areas of frequent gains and losses identified candidate genes that may be involved in different stages of MM: OSM (22q12.2), FUS1 and PL6 (3p21.3), DNAJA1 (9p21.1) and CDH2 (18q11.2-q12.3). Imbalances seen by ROMA were confirmed by Affymetrix genome analysis in a subset of samples., (Copyright (c) 2008 Wiley-Liss, Inc.)

Surgery for congenital and early childhood lung cysts is often dictated by symptoms such as respiratory distress, infection or pneumothorax. Asymptomatic cysts present a therapeutic dilemma: surgical intervention and "conservative" observation have advocates. The risk of malignancy in such cysts is considered by some an indication for surgical intervention and is reviewed in this paper. Pleuropulmonary blastoma (PPB) is the most frequent malignancy associated with childhood lung cysts. Although rare, PPB occurs predictably in certain clinical and familial situations. This unique biology of PPB can inform the cyst management decision. The earliest manifestation of PPB is a malignant lung cyst in young children, clinically and radiographically indistinguishable from benign congenital lung cysts. Histopathologic examination differentiates cystic PPB from the benign cystic variants. Surgical excision of cystic PPB (with or without chemotherapy) cures approximately 85-90% of children. If not excised, cystic PPB evolves to cystic/solid or solid high-grade sarcoma (cure rate 45-60%) by age 2-6 years. Numerous reports of "malignancy in a congenital lung cyst" are now understood as the characteristic progression of cystic PPB. PPB is genetically determined in many cases. Detailed family history may reveal the hallmarks of PPB in the patient or young relatives: a unique constellation of diseases including lung cysts, cystic nephroma, childhood cancers, stromal sex-chord ovarian tumors, seminomas or dysgerminomas, intestinal polyps, thyroid hyperplasias, and hamartomas. Pneumothorax and multifocal/bilateral lung cysts also characterize PPB. These diagnoses predict that a lung cyst is more likely PPB than a benign congenital cyst. Patients fitting this pattern deserve histologic diagnosis. The genetic basis for this heritable syndrome is unknown but is being actively investigated., (Copyright 2008 Wiley-Liss, Inc.)

Patients with malignant pleural mesothelioma and negative N2 stage lymph nodes may benefit from extrapleural pneumonectomy with adjuvant therapy. The objective of this study is to describe the use of EUS-FNA to determine N2 stage status in patients with mesothelioma and its impact in the management of such patients. Six patients (mean age, 62 yr; median age, 63 yr; range, 52-70 yr; 5 men; 1 woman) underwent EUS-FNA for staging of N2 lymph nodes from July 2000 to July 2006. Follow-up included operative notes, treatment summaries, and surgical pathology. Eight sites were aspirated: four subcarinal lymph nodes, three aorto-pulmonary window lymph nodes, and one paraesophageal mass. Two of 8 (25%) aspirates were positive for metastatic disease in two different patients. Two false negative EUS-FNAs were observed and were attributed to sampling error not diagnostic error. No complications were observed. EUS-FNA is a safe N2 node staging technique in patients with mesothelioma. A positive N2 lymph node by EUS-FNA may be a contraindication to definitive surgery in patients with malignant mesothelioma.

Homogeneity of mesothelial and lymphatic endothelial cells, express some markers that are presumed to be exclusive of the endothelium was recently reported. This similarity is important to improve the diagnosis and prognosis of malignant mesothelioma (MM). Additionally, some of these markers provide the rationale for specific molecular-targeted novel therapies aimed at MM, an aggressive malignant neoplasm, with an usually dismal prognosis. The goal of our study was to determine the prevalence and expression pattern of VEGF receptor-3 (VEGFR-3) immunoreactivity in MM and whether this immunoreactivity occurs in different phenotypes of this neoplasm. Formalin-fixed and paraffin-embedded samples from 29 MM cases and 5 metastatic carcinomas were immuno-stained for VEGFR-3 according to the streptavidin-biotin-peroxidase complex technique using a primary antibody (Zymed Laboratories, CA, USA) diluted at 1:200. Lymphatic vessels (LV) were outlined mainly in the peripheral area surrounding the neoplasms. Blood vessels were only rarely positive for VEGFR-3 in a pattern easily distinguishable from LV. In 25 out of 29 cases (86.2%) LV were strongly positive for VEGFR-3: 14 cases (48.2%) exhibited positive VEGFR-3 reactivity in malignant cells. Epitheliod MM showed a moderate to intense VEGFR-3 positive reaction in LV from 8 out of 19 cases. Among the other histological subtypes, a positive VEGFR-3 reaction was noted in malignant cells from two cases of transitional and one case of pleomorphic MM. Malignant cells from two out of three biphasic and one out of three sarcomatoid MM were also positive for VEGFR-3. Interestingly, one case of the multicystic subtype was negative for VEGFR-3 in malignant cells and faintly positive in an occasional LV. All cases of metastatic carcinoma were negative for VEGFR-3 in the neoplastic cells. In conclusion, VEGFR-3 was expressed in malignant cells from different subtypes of MM, reinforcing the putative role of this marker as a potential therapeutic target in this group of neoplasia., (Copyright 2007 Wiley-Liss, Inc.)

Asbestos pollution is a global problem. Asbestos exposure induced mesothelioma does not require an 'occupational' type of exposure. Bystander exposures may result in earlier age of disease onset and more aggressive disease progression as described in the following 3 case reports., (Copyright 2007 Wiley-Liss, Inc.)

Solitary fibrous tumors (SFTs) of the pleura are rare soft-tissue tumors that are presumed to be of mesenchymal origin. Most SFTs are histologically benign, but up to 20% of SFTs may be malignant. In addition, malignant transformation may occur within histologically benign SFTs, though it is rare. However, it is difficult to diagnose malignant SFTs of the pleura by means of conventional computed tomography and magnetic resonance imaging (MRI). In this article we present the first case of malignant SFT of the pleura in an 81-year-old man in which the apparent diffusion coefficient (ADC) value and ADC map based on diffusion-weighted MRI were very useful for identifying malignant transformation., (Copyright 2007 Wiley-Liss, Inc.)

Individual response to oxidative stress, due to exposure to asbestos fibres plays a significant role in the malignant pleural mesothelioma (MPM) etiology. The differential impact on MPM risk of polymorphic alleles of glutathione-S-transferases (GSTs) and manganese superoxide dismutase (MnSOD/SOD2) genes involved in the defence against oxidative damage has been investigated. Ninety cases of MPM and 395 controls were genotyped using the arrayed-primer extension technique. Logistic regression analysis was applied to assess the predictive role of single nucleotide polymorphisms (SNPs) potentially involved in MPM carcinogenesis after adjustment for potential confounders. An increased risk of MPM was found in subjects bearing a GSTM1 null allele (OR = 1.69, 95% CI = 1.04-2.74; p = 0.034), and in those with the Ala/Ala genotypes at codon 16 within MnSOD (OR = 3.07, 95% CI = 1.55-6.05; p = 0.001). A stronger effect of MnSOD was observed among patients without a clear exposure to asbestos fibres. No effect was found for GSTA2, GSTA4, GSTM3, GSTP1 and GSTT1 genes. These findings, if replicated, contribute substantial evidence to the hypothesis that oxidative stress and cellular antireactive oxygen species systems are involved in the pathogenesis and in the natural history of MPM.

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor described in diverse locations including lung and liver. Relative to these sites, primary EHE of the serous cavities is uncommon. EHE in the serous cavities mimics mesothelioma and adenocarcinoma clinically, radiographically, cytologically, and histologically. EHEs have plasmacytoid epithelioid cells with cytoplasmic vacuoles. In addition to these features, we noted eccentric nuclei with abundant eosinophilic cytoplasm and nuclei displaced peripherally by globular cytoplasmic inclusions imparting a "rhabdoid" phenotype. These cells were often seen surrounding a hyaline core. Rhabdoid features are not unique to a single entity, and a comprehensive immunohistochemical panel is essential. We report the occurrence of pleural EHE with rhabdoid features presenting in a pleural effusion, and review the literature of primary serosal EHEs., ((c) 2007 Wiley-Liss, Inc.)

Malignant mesothelioma is an aggressive neoplasm linked to asbestos exposure. Most mesothelioma patients present with pleural effusion and the fluid is typically sent for cytological examination. Therefore, cytopathologists are most familiar with features of mesothelioma in fluid preparations. We present here a case of malignant mesothelioma with unusual cytological features diagnosed on FNA. The diagnosis was confirmed by immuno-histochemical and electron microscopic studies. In addition, we compare the cytomorphological features observed in malignant effusion versus fine-needle aspiration.