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Lymphomatoid granulomatosis (LYG) is an uncommon angiocentric and angiodestructive T-cell rich, Epstein-Barr virus (EBV) positive B-cell multisystem lymphoproliferative disorder, predominately affecting the lungs. Since both clinical presentation and radiographic imaging findings, including X-ray and computed tomographic (CT), are nonspecific, the ultimate diagnosis of LYG relies on lung tissue sample diagnosis with its WHO grading based on the degree of cytologic atypia, necrosis and density of EBV positive B-cells. In addition, its histopathologic grading is correlated with clinical manifestation with high grade LYG mimicking aggressive B-cell lymphoma. Discordant grading between pulmonary and cutaneous LYG lesion has have been observed and might be a potential diagnostic and prognostic pitfall. F18-FDG PET/CT has been used to monitor disease progression and treatment response. In this study, we reviewed and summarized the clinical role of F18-FDG PET/CT in the surveillance of high grade pulmonary LYG, and examined its limitations in grading multisystem LYG.

Objectives The 2019 Workshop of the Society for Hematopathology/European Association for Haematopathology received and reviewed cases covering the spectrum of mastocytosis and related diseases, including morphologic mimics, focusing on recent updates and relevant findings for pathologists. Methods The workshop panel reviewed 99 cases of cutaneous and systemic mastocytosis (SM) and SM and associated hematologic neoplasms (SM-AHN). Results Despite a common theme of KIT mutation (particularly D816V), mastocytosis is a heterogeneous neoplasm with a wide variety of presentations. This spectrum, including rare subtypes and extramedullary organ involvement, is discussed and illustrated by representative cases. Conclusions In the age of targeted treatment aimed at KIT, the accurate diagnosis and classification of mastocytosis has major implications for therapy and further interventions. Understanding the clinical, pathologic, and genetic findings of mastocytosis is crucial for selecting the proper tests to perform and subsequent arrival at a correct diagnosis in this rare disease.

Introducing a sensitive and specific peripheral blood flow cytometric assay for Sézary syndrome and mycosis fungoides (SS/MF) requires careful selection of assay design characteristics, and translation into a laboratory developed assay through development/optimization, validation, and continual quality monitoring. As outlined in a previous article in this series, the recommended design characteristics of this assay include at a minimum, evaluation of CD7, CD3, CD4, CD8, CD26, and CD45, analyzed simultaneously, requiring at least a 6 color flow cytometry system, with both quantitative and qualitative components. This article provides guidance from an international group of cytometry specialists in implementing an assay to those design specifications, outlining specific considerations, and best practices. Key points presented in detail are: (a) Pre-analytic components (reagents, specimen processing, and acquisition) must be optimized to: (i) identify and characterize an abnormal population of T-cells (qualitative component) and (ii) quantitate the abnormal population (semi/quasi-quantitative component). (b)Analytic components (instrument set-up/acquisition/analysis strategy and interpretation) must be optimized for the identification of SS/MF populations, which can vary widely in phenotype. Comparison with expert laboratories is strongly encouraged in order to establish competency. (c) Assay performance must be validated and documented through a validation plan and report, which covers both qualitative and semi/quasi-quantitative assay components (example template provided). (d) Ongoing assay-specific quality monitoring should be performed to ensure consistency.

BACKGROUND Blood involvement by mycosis fungoides (MF)/Sezary syndrome (SS) influences prognosis and therapeutic decisions. MF/SS blood stage is currently determined by absolute CD4 + CD26- or CD4 + CD7-cell counts, which quantification method may overestimate MF/SS by including CD26- or CD7- normal CD4+ T-cells, or underestimate disease burden when MF/SS cells show incomplete loss of CD26 and/or CD7. Recently, through the standardization effort led by the International Clinical Cytometry Society (ICCS), recommendation was made to quantify MF/SS by enumerating immunophenotypically aberrant CD4+ T-cells, rather than CD26- or CD7- in isolation. METHODS We compared these two quantitation methods in 309 MF/SS patients who had blood samples analyzed by flow cytometry immunophenotyping (FCI) over a 1-year period. RESULTS Using the European Organization of Research and Treatment of Cancer (EORTC)/International Society for Cutaneous Lymphomas (ISCL) criteria, 221 (71.5%) patients had a blood stage corresponding to B0, 57 (18.4%) to B1, and 31 (10%) to B2. By FCI analysis, a total of 62 patients (20.0%) were found positive for MF/SS. Among EORTC B0 patients, 11/221 (5%) were positive by FCI (false negatives), and among EORTC Stage B1 patients, 35/57 (61%) were negative by FCI (false positives). Regarding patients positive for MF/SS cells by FCI, there was an overall excellent correlation (r = .999, p

Plasmablastic lymphoma (PBL) is a rare subtype of large B-cell lymphoma most commonly seen in immunocompromised patients, particularly in those with HIV infection. In these patients, PBL often affects the oral mucosa.1 Other immunocompromised states, including immunosuppression for organ transplant and immunosenescence, have been linked to PBL.1 Epstein-Barr virus (EBV) reactivation is thought to be a major driver of PBL.1 PBL is characterized histologically by an absence of B- and T-cell markers and expression of plasma cell markers CD38 and CD138. The median overall survival of HIV-positive and HIV-negative patients with PBL is 15 months and 9 months, respectively.1 Some patients with PBL present with primary cutaneous disease (pcPBL), defined as no systemic involvement. These patients have a unique clinical presentation and an indolent course. We report the first case of iatrogenic pcPBL secondary to romidepsin therapy for primary cutaneous peripheral T-cell lymphoma not otherwise specified (pcPTCL-NOS).

Histiocytic sarcoma (HS) is a rare malignancy with morphologic and immunophenotypic features indicating histiocytic differentiation. We present a case of HS with multisystem involvement, including an obstructing mass in the pancreatic head.

Objectives To report the findings of the 2019 Society for Hematopathology/European Association for Haematopathology Workshop within the categories of reactive eosinophilia, hypereosinophilic syndrome (HES), germline disorders with eosinophilia (GDE), and myeloid and lymphoid neoplasms associated with eosinophilia (excluding entities covered by other studies in this series). Methods The workshop panel reviewed 109 cases, assigned consensus diagnosis, and created diagnosis-specific sessions. Results The most frequent diagnosis was reactive eosinophilia (35), followed by acute leukemia (24). Myeloproliferative neoplasms (MPNs) received 17 submissions, including chronic eosinophilic leukemia, not otherwise specified (CEL, NOS). Myelodysplastic syndrome (MDS), MDS/MPN, and therapy-related myeloid neoplasms received 11, while GDE and HES received 12 and 11 submissions, respectively. Conclusions Hypereosinophilia and HES are defined by specific clinical and laboratory criteria. Eosinophilia is commonly reactive. An acute leukemic onset with eosinophilia may suggest core-binding factor acute myeloid leukemia, blast phase of chronic myeloid leukemia, BCR-ABL1–positive leukemia, or t(5;14) B-lymphoblastic leukemia. Eosinophilia is rare in MDS but common in MDS/MPN. CEL, NOS is a clinically aggressive MPN with eosinophilia as the dominant feature. Bone marrow morphology and cytogenetic and/or molecular clonality may distinguish CEL from HES. Molecular testing helps to better subclassify myeloid neoplasms with eosinophilia and to identify patients for targeted treatments.

Objectives To summarize cases submitted to the 2019 Society for Hematopathology/European Association for Haematopathology Workshop under the category of myeloid/lymphoid neoplasms with eosinophilia and PDGFRA, PDGFRB, or FGFR1 or with PCM1-JAK2 rearrangements, focusing on recent updates and relevant practice findings. Methods The cases were summarized according to their respective gene rearrangement to illustrate the spectrum of clinical, laboratory, and histopathology manifestations and to explore the appropriate molecular genetic tests. Results Disease presentations were heterogeneous, including myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDSs), MDS/MPN, acute myeloid leukemia, acute B- or T-lymphoblastic lymphoma/acute lymphoblastic lymphoma (ALL/LBL), or mixed-lineage neoplasms. Frequent extramedullary involvement occurred. Eosinophilia was common but not invariably present. With the advancement of RNA sequencing, cryptic rearrangements were recognized in genes other than PDGFRA. Additional somatic mutations were more frequent in the FGFR1-rearranged cases. Cases with B-ALL presentations differed from Philadelphia-like B-ALL by the presence of an underlying MPN. Cases with FLT3 and ABL1 rearrangements could be potential candidates for future inclusion in this category. Conclusions Accurate diagnosis and classification of this category of myeloid/lymphoid neoplasms has important therapeutic implications. With the large number of submitted cases, we expand our understanding of these rare neoplasms and improve our ability to diagnose these genetically defined disorders.

Worldwide, millions of women live with breast implants. Therefore, it is important that physicians be aware of an uncommon but possibly serious complication arising from breast implants: breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). Breast implant-associated anaplastic large-cell lymphoma most commonly presents as a delayed fluid collection around a textured breast implant or as a mass in the capsule surrounding the implant. The exact pathogenesis of the disease remains unclear. The neoplastic cells of BIA-ALCL show strong uniform staining for CD30 and are consistently negative for activin receptor-like kinase 1. Patients with confirmed cases should be referred to a lymphoma specialist or breast medical oncologist for a complete oncologic evaluation before any surgical intervention. For disease confined to the fluid accumulation or capsule, or both, surgical removal of the implant and complete capsulectomy is the preferred treatment. Postoperative chemotherapy or radiation, or both, are not considered necessary for patients with limited-stage disease and are reserved for advanced disease stages. Generally, BIA-ALCL is a local disease that follows an indolent course and has an excellent prognosis. Although complete remission of disease has occurred in patients with BIA-ALCL, median overall survival is reduced. As of March 2018, approximately 529 unique, confirmed BIA-ALCL cases had been reported in 23 countries. To date, 16 patients have died from BIA-ALCL, and all had extracapsular involvement. The aim of this article is to summarize the diagnosis, evaluation, and management of BIA-ALCL, based on established guidelines, for all practitioners who may care for patients with breast implants.Des millions de femmes vivent avec des implants mammaires dans le monde. Il est donc important que les médecins connaissent le lymphome anaplasique à grandes cellules associé aux implants mammaires (LAGC-IM), une complication peu fréquente, mais au potentiel grave. Le LAGC-IM prend généralement la forme d’une accumulation tardive de liquide autour d’un implant mammaire texturé ou d’une masse dans la capsule qui entoure l’implant. La pathogenèse exacte de la maladie demeure floue. Les cellules néoplasiques du LAGC-IM démontrent une coloration marquée et importante du CD30 et sont constamment négatives pour la kinase-1 analogue au récepteur d’activine. Les patients diagnostiqués doivent être dirigés vers un spécialiste des lymphomes ou un oncologue spécialisé en cancer du sein pour subir une évaluation oncologique complète avant toute intervention chirurgicale. Lorsque la maladie se limite à une accumulation de liquide, à la capsule ou à ces deux éléments, le traitement privilégié est l’exérèse chirurgicale de l’implant et la capsulectomie complète. La chimiothérapie postopératoire, la radiothérapie ou ces deux interventions ne sont pas considérées comme nécessaires pour les patientes ayant une maladie limitée, mais sont réservées aux maladies avancées. En général, le LAGC-IM est une maladie localisée à évolution lente et à l’excellent pronostic. Même si des patientes présentant un LAGC-IM se sont complètement rétablies, la survie médiane globale est réduite. En mars 2018, environ 529 cas uniques et confirmés de LAGC-IM avaient été signalés dans 23 pays. Jusqu’à présent, 16 patientes sont décédées d’un LAGC-IM, et toutes présentaient une atteinte extracapsulaire. Le présent article vise à résumer le diagnostic, l’évaluation et la prise en charge du LAGC-IM d’après des directives établies, et ce, pour tous les praticiens susceptibles de soigner des patientes ayant des implants mammaires.

Peripheral blood involvement by cutaneous T-cell lymphoma is typically assessed by flow cytometry and plays a critical role in diagnosis, classification, and prognosis. Simplified strategies to detect tumor cells (Sezary cells) fail to exclude reactive subsets, whereas tumor-specific abnormalities are subtle and inconsistently present. We implemented a flow cytometric strategy to detect clonal Sezary cells based on the monotypic expression of one of two mutually exclusive TCR constant β chains, TRBC1 and TRBC2. Analysis of CD4+ T-cell subsets and TCR variable β classes from healthy donors showed polytypic TRBC1 staining. Clonal Sezary cells were identified by TRBC1 staining in 56 of 111 (50%) samples from patients with cutaneous T-cell lymphoma, accounting for 7–18,155 cells/μl and including 13 cases (23%) lacking tumor-specific immunophenotypic abnormalities. CD4+ T-cell subsets from 86 patients without T-cell lymphoma showed polytypic TRBC1 staining, except for five patients (6%) with minute T-cell clones of uncertain significance accounting for 53–136 cells/μl. Assessment of TRBC1 expression within a comprehensive single-tube flow cytometry assay effectively overcomes interpretative uncertainties in the identification of Sezary cells without the need for a separate T-cell clonality assay.

Blood involvement by mycosis fungoides (MF)/Sézary syndrome (SS) influences prognosis and therapeutic decisions. MF/SS blood stage is currently determined by absolute CD4 + CD26- or CD4 + CD7-cell counts, which quantification method may overestimate MF/SS by including CD26- or CD7- normal CD4+ T-cells, or underestimate disease burden when MF/SS cells show incomplete loss of CD26 and/or CD7. Recently, through the standardization effort led by the International Clinical Cytometry Society (ICCS), recommendation was made to quantify MF/SS by enumerating immunophenotypically aberrant CD4+ T-cells, rather than CD26- or CD7- in isolation.We compared these two quantitation methods in 309 MF/SS patients who had blood samples analyzed by flow cytometry immunophenotyping (FCI) over a 1-year period.Using the European Organization of Research and Treatment of Cancer (EORTC)/International Society for Cutaneous Lymphomas (ISCL) criteria, 221 (71.5%) patients had a blood stage corresponding to B0, 57 (18.4%) to B1, and 31 (10%) to B2. By FCI analysis, a total of 62 patients (20.0%) were found positive for MF/SS. Among EORTC B0 patients, 11/221 (5%) were positive by FCI (false negatives), and among EORTC Stage B1 patients, 35/57 (61%) were negative by FCI (false positives). Regarding patients positive for MF/SS cells by FCI, there was an overall excellent correlation (r = .999, p .001) between the EORTC/ISCL method and FCI method; however, four (6.5%) patients would have an altered B stage between B0 and B1.The MF/SS cell quantification method using immunophenotypic aberrancies, as recommended by the ICCS, allows to distinguish MF/SS cells from background benign T-cells and enables for more accurate staging, especially among patients currently being considered to have B0 and B1 stage diseases.

Histiocytic sarcoma (HS) is a rare malignancy with morphological and immunophenotypic features of histocytes. We present a case of histiocytic sarcoma with multisystem involvement, including an obstructing pancreatic head mass. F18-FDG PET/CT is a valuable tool in staging and assessment of response to therapy in this rare entity. Knowing the diverse metastatic pattern of HS will help avoid imaging pitfalls for the diagnosis after pathologic diagnosis is made.

A peripheral blood flow cytometric assay for Sézary syndrome (SS) or circulating mycosis fungoides (MF) cells must be able to reliably identify, characterize, and enumerate T‐cells with an immunophenotype that differs from non‐neoplastic T‐cells. Although it is also important to distinguish SS and MF from other subtypes of T‐cell neoplasm, this usually requires information in addition to the immunophenotype, such as clinical and morphologic features. This article outlines the approach recommended by an international group with experience and expertise in this area. The following key points are discussed: (a) At a minimum, a flow cytometric assay for SS and MF should include the following six antibodies: CD3, CD4, CD7, CD8, CD26, and CD45. (b) An analysis template must reliably detect abnormal T‐cells, even when they lack staining for CD3 or CD45, or demonstrate a phenotype that is not characteristic of normal T‐cells. (c) Gating strategies to identify abnormal T‐cells should be based on the identification of subsets with distinctly homogenous immunophenotypic properties that are different from those expected for normal T‐cells. (d) The blood concentration of abnormal cells, based on any immunophenotypic abnormalities indicative of MF or SS, should be calculated by either direct enumeration or a dual‐platform method, and reported.

Background: At our institution, RNs have performed bone marrow aspiration and biopsy procedures for more than 10 years. A recent review of our institutional policies and practices regarding RN-performed bone marrow procedures was intended to ensure that we were using a safe and evidence-based approach and prompted this program evaluation. Methods We conducted a literature search and review of our institutional policies and practices regarding RN-performed bone marrow procedures. All elements of our clinical practice were reviewed and evaluated, including outcomes. Results Between 2010 and 2017, the RN team completed a total of 10,867 bone marrow procedures in our hospital-based ambulatory infusion center. The team included 15 nurses who completed up to eight patient procedures each weekday. Patient satisfaction rates were consistently high and complication rates were very low: less than 1% of all patients experienced postprocedure bleeding, and less than 2% required urgent medical care within 24 hours of the procedure. In an analysis of bone marrow procedures performed between 2016 and 2017, the quality of bone marrow samples obtained by the RN team remained high, consistently meeting or exceeding our 95% clinical adequacy goal. Conclusions There is limited evidence in the literature supporting the practice of RN-performed bone marrow procedures. Our review revealed a robust program with excellent clinical and diagnostic outcomes that can be emulated by other institutions interested in pursuing RN-performed bone marrow procedures.

Background:\ud Pyoderma gangrenosum (PG) is an uncommon dermatosis with a limited evidence base for treatment.\ud \ud Objective:\ud We sought to estimate the effectiveness of topical therapies in the treatment of patients with PG.\ud \ud Methods:\ud This was a retrospective cohort study of UK secondary care patients with a clinical diagnosis of PG that was suitable for topical treatment (recruited between July 2009 and June 2012). Participants received topical therapy after normal clinical practice (primarily topical corticosteroids [classes I-III] and tacrolimus 0.03% or 0.1%). The primary outcome was speed of healing at 6 weeks. Secondary outcomes included the following: proportion healed by 6 months; time to healing; global assessment; inflammation; pain; quality of life; treatment failure; and recurrence.\ud \ud Results:\ud Sixty-six patients (22-85 years of age) were enrolled. Clobetasol propionate 0.05% was the most commonly prescribed therapy. Overall, 28 of 66 (43.8%) ulcers healed by 6 months. The median time to healing was 145 days (95% confidence interval, 96 days to ∞). Initial ulcer size was a significant predictor of time to healing (hazard ratio, 0.94 [95% confidence interval, 0.88-1.00); P = .043). Four patients (15%) had a recurrence.\ud \ud Limitations:\ud Our study did not include a randomized comparator.\ud \ud Conclusion:\ud Topical therapy is potentially an effective first-line treatment for PG that avoids the possible side effects associated with systemic therapy. It remains unclear whether more severe disease will respond adequately to topical therapy alone.

Flow cytometry (FC) has a well-established role in the diagnostic evaluation of mature B-cell neoplasms. Effective assessment for lineage associated antigens, aberrant antigen expression, and immunoglobulin light chain restriction requires a well-designed, optimized, and controlled FC assay. However, it is important for hematopathologists to know when flow cytometry has a more limited role, and other modalities, such as immunohistochemistry, cytogenetic and molecular testing, are more important. This review will discuss the features of an optimal FC assay for the evaluation of mature B-cell neoplasms, and the current role of FC in the diagnosis and sub-classification, prognostic assessment, identification of therapeutic targets, and assessment for disease response to therapy. © 2018 International Clinical Cytometry Society.

We present serial

The Case Study Interpretation (CSI) cases presented at the 2014 International Clinical Cytometry Society (ICCS) meeting in Seattle illustrate the utility of state-of-the art multiparameter flow cytometry in the diagnosis of hematolymphoid neoplasms. Download the listmode files (Supporting Information) and test your analysis skills before reading the case reports, keeping in mind the following questions. How many separate abnormal mature B-cell populations can you identify, and how many of these represent different subtypes of B-cell neoplasm? How many separate abnormal mature T-cell populations can you identify, and do these represent different subtypes of T-cell neoplasm or phenotypic heterogeneity in one neoplasm? How many separate immature/blastic cell populations can you identify, and do they meet criteria for mixed phenotype leukemia? Is there a population of blasts that lacks T-cell, B-cell, and myeloid lineage defining antigens and if so, what entities should you consider and what additional antigens should you assess for?

Objective To determine whether ciclosporin is superior to prednisolone for the treatment of pyoderma gangrenosum, a painful, ulcerating skin disease with a poor evidence base for management. Design Multicentre, parallel group, observer blind, randomised controlled trial. Setting 39 UK hospitals, recruiting from June 2009 to November 2012. Participants 121 patients (73 women, mean age 54 years) with clinician diagnosed pyoderma gangrenosum. Clinical diagnosis was revised in nine participants after randomisation, leaving 112 participants in the analysis set (59 ciclosporin; 53 prednisolone). Intervention Oral prednisolone 0.75 mg/kg/day compared with ciclosporin 4 mg/kg/day, to a maximum dose of 75 and 400 mg/day, respectively. Main outcome measures The primary outcome was speed of healing over six weeks, captured using digital images and assessed by blinded investigators. Secondary outcomes were time to healing, global treatment response, resolution of inflammation, self reported pain, quality of life, number of treatment failures, adverse reactions, and time to recurrence. Outcomes were assessed at baseline and six weeks and when the ulcer had healed (to a maximum of six months). Results Of the 112 participants, 108 had complete primary outcome data at baseline and six weeks (57 ciclosporin; 51 prednisolone). Groups were balanced at baseline. The mean (SD) speed of healing at six weeks was −0.21 (1.00) cm 2 /day in the ciclosporin group compared with −0.14 (0.42) cm 2 /day in the prednisolone group. The adjusted mean difference showed no between group difference (0.003 cm 2 /day, 95% confidence interval −0.20 to 0.21; P=0.97). By six months, ulcers had healed in 28/59 (47%) participants in the ciclosporin group compared with 25/53 (47%) in the prednisolone group. In those with healed ulcers, eight (30%) receiving ciclosporin and seven (28%) receiving prednisolone had a recurrence. Adverse reactions were similar for the two groups (68% ciclosporin and 66% prednisolone), but serious adverse reactions, especially infections, were more common in the prednisolone group. Conclusion Prednisolone and ciclosporin did not differ across a range of objective and patient reported outcomes. Treatment decisions for individual patients may be guided by the different side effect profiles of the two drugs and patient preference. Trial registration Current Controlled Trials ISRCTN35898459.

Objective The aim of this study is to illustrate a practical approach to the identification of prognostically important subtypes of large B-cell lymphomas. Study design Twenty-six cases of large B-cell lymphoma in the base of the tongue and oral cavity were retrieved from 2003 through 2012. All cases were classified based on the 2008 World Health Organization criteria. Hematoxylin-eosin–stained sections, immunohistochemical stains, flow cytometric immunophenotypic data, and fluorescence in situ hybridization studies were performed and evaluated. Results Four different subtypes of large B-cell lymphoma were identified: pleomorphic variant mantle cell lymphoma, Epstein-Barr virus–positive diffuse large B-cell lymphoma of the elderly, diffuse large B-cell lymphoma not otherwise specified, and B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma, including a case of double-hit lymphoma. Conclusions Diverse subtypes of large B-cell lymphoma were identified in the base of tongue and oral cavity, and illustrate a practical approach to recognizing prognostically important lymphoma subtypes.

We present serial 18F-FDG PET/CT findings in a case of grade 3 pulmonary lymphomatoid granulomatosis positive for the Epstein–Barr virus. The patient experienced a transient complete response to R-CHOP chemotherapy and subsequent multisystem recurrence, predominately involving the subcutaneous region of the torso on 18F-FDG PET/CT. Biopsy of the most hypermetabolic subcutaneous lesion demonstrated grade 1 cutaneous lymphomatoid granulomatosis negative for the Epstein–Barr virus. This report highlights the role of 18F-FDG PET/CT in characterizing and monitoring disease progression and regression, as well as the limitations of 18F-FDG PET/CT in accurate grading of multisystem recurrence, given the diversity of clinical and histopathologic features of lymphomatoid granulomatosis.

Introduction There have been few recent therapeutic advances in T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL), a rare and aggressive malignancy. Intensive chemotherapy +/- allogeneic transplantation (AlloHCT) can effect cure, realized by only a minority of adults. In distinction to B-ALL, there have been no safe/effective targeted therapies developed in T-ALL/LBL. We therefore performed a focused tissue array to identify novel tumor proteins, including CCR4; evaluated together with established immunophenotypic (IP) T-ALL/LBL subtypes [early-T-precursor (ETP), early non-ETP (Pre/Pro-T), common & late thymocyte]. We evaluated the clinical phenotype and outcome together with clinical and epidemiologic data in patients diagnosed at the 3-site Mayo Clinic Cancer Center (MCCC: Rochester, MN; Phoenix, AZ; and Jacksonville, FL). Methods Following IRB approval, we identified 50 consecutive T-ALL/LBL patients from 1997 -2019 diagnosed at the 3-site MCCC. Available remnant leukemia/lymphoma paraffin blocks were identified (n=28). Using immunohistochemistry (IHC) we evaluated expression of leukemic antigens of interest (CCR4, CD47, BCL2, BCL6, PD-L1, CD38 and CD123); these were selected based on clinical availability of novel targeted agents, approved or in development for other indications. Tissue array studies were performed and interpreted by a single hematopathologist (L.J) blinded to clinical data, using positive and negative controls, according to standard techniques. We also evaluated the clinical and epidemiological parameters, including different IP subtypes [ETP: CD1a-, sCD3- & CD8-, Pre/Pro-T: CD1a-, sCD3- & CD8+ or CD8- (11 marker T-ALL IP score was used to distinguish CD8- ETP vs. Pre/Pro-T), thymic: CD1a+ and mature: CD1a- & sCD3+] (Khogeer et al., Br J Haematol., 2019) & the presence of the unique MLLT10-PICALM fusion (n=6), as well as therapy and outcome. Comparisons of characteristics and outcomes of interest were made using a Wilcoxon rank sum test (continuous characteristics) or Fisher's exact test (categorical characteristics), unadjusted Cox proportional hazards regression models (overall survival), or unadjusted logistic regression models (complete remission after first line treatment). Results We identified the expression of novel targetable tissue proteins in all adult T-ALL/LBL cases [Table 1]. BCL2, CD38 & CD47 were expressed in majority of the cases, and CCR4 [Fig. 1] was expressed in 11/28 (39.3%) cases. CCR4 expression was significantly more common in the Pre/Pro-T (75%) vs. other IP subtypes (19%) (p=0.011); there was no other association of CCR4 expression with clinical characteristics/outcomes. We also observed differences in T-ALL vs. T-LBL, specifically T-ALL patients were more likely to be male (71% vs. LBL 38.9%, p=0.038). Surprisingly, T-LBL patients were more likely to have a family history of leukemia/lymphoma (41.2% vs. T-ALL 0%, p In contrast, we observed an important association of IP subtype with outcome after therapy, including complete remission (p=0.035), & a trend suggesting differences in survival (p=0.069) [Table 3]. However, MLLT10-PICALM was not associated with any unique clinical features or with outcome (death, p=0.85; CR, p=0.98), although 4/6 patients underwent AlloHCT, suggesting an important role of AlloHCT in this subgroup. No other significant association of epidemiologic risk factors with phenotype or outcome was noted. Conclusion Using focused tissue array we have identified expression of tumor associated proteins in T-ALL/LBL including CCR4 (Pre/Pro-T IP) & others, which may be targets of therapeutic agents like mogamulizumab. Furthermore, our analysis demonstrates an important clinical impact of IP subtype in T-ALL/LBL, as well as important clinical & therapeutic differences in T-ALL vs. LBL. This study will help guide development of targeted clinical trials in T-ALL/LBL (CCR4 trial already in development). Further analyses are planned to determine the clinical & epidemiologic association of genetic lesions in this cohort. Disclosures Foran: Agios: Honoraria, Research Funding.

Background Although many clinical laboratories are adopting higher color flow cytometric assays, the approach to optimizing panel design and data analysis is often traditional and subjective. In order to address the question “What is the best flow cytometric strategy to reliably distinguish germinal center B-cell lymphoma (GC-L) from germinal center hyperplasia (GC-H)?” we applied a computational tool that identifies target populations correlated with a desired outcome, in this case diagnosis. Design Cases of GC-H and GC-L evaluated by flow cytometric immunophenotyping using CD45, CD20, kappa, lambda, CD19, CD5, CD10, CD38, were analyzed with flowType and RchyOptimyx to construct cellular hierarchies that best distinguished the two diagnostic groups. Results The population CD5−CD19+CD10+CD38− had the highest predictive power. Manual reanalysis confirmed significantly higher CD10+/CD38−B-cells in GC-L (median 12.44%, range 0.74–63.29, n = 52) than GC-H (median 0.24%, 0.03–4.49, n = 48, P = 0.0001), but was not entirely specific. Difficulties encountered using this computational approach included the presence of CD10+ granulocytes, continuously variable B-cell expression of CD38, more variable intensity antigen staining in GC-L and inability to assess the contribution of light chain restriction. Conclusion Computational analysis with construction of cellular hierarchies related to diagnosis helped guide manual analysis of high dimensional flow cytometric data. This approach highlighted the diagnostic utility of CD38 expression in the evaluation of B-cells with a CD10+ GC phenotype. In contrast to computational analysis of non-neoplastic cell populations, evaluation of neoplastic cells must be able to take into consideration increased variability in antigen expression. © 2013 International Clinical Cytometry Society

Background: T-cell immunoglobulin mucin-3 (TIM3) has recently been described as an acute myeloid leukemia (AML) stem cell antigen expressed on leukemic myeloblasts, but not on normal hematopoietic stem cells. TIM3 is also expressed by monocytes, natural killer cells, and several T cell subsets; however, normal myeloblasts have not been well-characterized or compared to AML. A specific flow cytometric marker capable of separating leukemic myeloblasts from non-neoplastic myeloblasts would be diagnostically useful, especially in the post-chemotherapy setting. Methods: TIM3 myeloblast expression was assessed in 69 bone marrow and/or peripheral blood specimens, including 27 AML and 42 non-neoplastic cases (20 with a recent history of chemotherapy). TIM3 median fluorescence intensity (MFI) was evaluated within myeloblast, monocyte, T cell, and natural killer cell populations. Results: The median percentage of myeloblasts positive for TIM3 was lower in non-neoplastic specimens without a history of recent chemotherapy (50.3%) as compared to AML (71.4%), but not significantly different as compared to non-leukemic myeloblasts in the post-chemotherapy setting (72.4%). Mean myeloblast TIM3 MFI was higher in AML myeloblasts and non-leukemic myeloblasts in the post-chemotherapy setting as compared to non-neoplastic myeloblasts in cases lacking a history of chemotherapy. Mean monocyte, natural killer cell, and T-cell TIM3 MFI remained relatively constant in varied clinical settings. Conclusions: We confirm that leukemic myeloblasts overexpress TIM3 as compared to non-neoplastic controls; however, high levels of expression may also be seen among non-leukemic myeloblasts in the post-chemotherapy setting. This overlap limits the diagnostic utility of TIM3 as a specific marker of neoplasia. © 2013 International Clinical Cytometry Society

Background: Laboratories utilize diverse methods to determine the absolute count used to distinguish chronic lymphocytic leukemia (CLL) from monoclonal B lymphocytosis, with many using dual platform (DP) methods (flow cytometric percent of CLL-like B cells × hematology analyzer white blood cell count). However, flow cytometric tube-to-tube variation may make interpretation difficult, particularly when the CLL-like B-cell count straddles the recommended threshold. This study investigates the extent, and potential sources, of this variability. Methods: Flow cytometric enumeration was performed on 20 samples with CLL-like B cells and 10 control specimens using single platform (SP) and two DP tubes A: kappa, lambda, CD5, CD10, CD19, CD38, CD45, CD20 and B: FMC-7, CD23, CD19, CD5, with and without racking to remove doublets. In addition, reproducibility studies were performed. Results: Three specimens showed discordant CLL-like B-cell counts relative to the threshold of 5 × 109/L. Bland–Altman analysis demonstrated a systematic bias with DP Tube B > A (5.9%) and SP > DP Tube A (9.5%). The doublet percent varied between specimens, but did not account for the bias between DP tubes. Variation was also seen in enumeration of other cell types, suggesting multiple potential sources of inconsistency. Conclusions: Significant tube-to-tube variation may be seen in CLL-like B-cell counts. The precise cause of these differences is uncertain, but is likely multifactorial. If the clinical utility of an absolute threshold for the diagnosis of CLL can be confirmed, it will be important to establish recommendations for standardization, similar to those employed for CD4 and CD34 enumeration. © 2013 International Clinical Cytometry Society

A 77-year-old white male presented to the clinic with two isolated cutaneous tumors on his forehead. A cutaneous biopsy showed a focally folliculotropic CD4 cutaneous lymphoma. The tumors were irradiated with a complete response, and he was started on oral bexarotene. He experienced localized cutaneous relapse 3 months into treatment. These new tumors now revealed a surprisingly CD8 cytotoxic phenotype, but with the same clone. A systemic workup was negative. His regimen was switched to romidepsin, and he was treated with local radiation again. Another 3.5 months passed in remission until he developed widespread cutaneous tumors. Positron emission tomography/computed tomography revealed multifocal systemic disease involving his diaphragm, liver, distal duodenum, proximal jejunum, anterior chest wall including pectoral muscles, and lungs without significant adenopathy. He died a few days later. Given his full clinical and pathological course, he was given the diagnosis of an aggressive primary cutaneous T-cell lymphoma, unspecified.

Background Blinding is the process of keeping treatment assignment hidden and is used to minimise the possibility of bias. Trials at high risk of bias have been shown to report larger treatment effects than low-risk studies. In dermatology, one popular method of blinding is to have independent outcome assessors who are unaware of treatment allocation assessing the endpoint using digital photographs. However, this can be complex, expensive and time-consuming. The objective of this study was to compare the effect of blinded and unblinded outcome assessment on the results of the STOP GAP trial. Methods The STOP GAP trial compared prednisolone to ciclosporin in treating pyoderma gangrenosum. Participants’ lesions were measured at baseline and at 6 weeks to calculate the primary outcome, speed of healing. Independent blinded assessors obtained measurements from digital photographs using specialist software. In addition, unblinded treating clinicians estimated lesion area by measuring length and width. The primary outcome was determined using blinded measurements where available, otherwise unblinded measurements were used (method referred to as trial measurements). In this study, agreement between the trial and unblinded measurements was determined using the intraclass correlation coefficient (ICC). The STOP GAP trial’s primary analysis was repeated using unblinded measurements only. We introduced differential and nondifferential error in unblinded measurements and investigated the effect on the STOP GAP trial’s primary analysis. Results Eighty-six (80%) of the 108 patients were assessed using digital images. Agreement between trial and unblinded measurements was excellent (ICC = 0.92 at baseline; 0.83 at 6 weeks). There was no evidence that the results of the trial primary analysis differed according to how the primary outcome was assessed (p value for homogeneity = 1.00). Conclusions Blinded digital image assessment in the STOP GAP trial did not meaningfully alter trial conclusions compared with unblinded assessment. However, as the process brought added accuracy and credibility to the trial it was considered worthwhile. These findings question the usefulness of digital image assessment in a trial with an objective outcome and where bias is not expected to be excessive. Further research should investigate if there are alternative, less complex ways of incorporating blinding in clinical trials. Trial registration Current Controlled Trials, www.isrctn.com ISRCTN35898459. Registered on 26 May 2009. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1779-9) contains supplementary material, which is available to authorized users.

Background: Fine-needle aspiration (FNA) coupled with flow cytometry (FC) can be helpful in suspicious pediatric lymph nodes or masses to exclude a lymphoproliferative disorder. The aim of this study was to analyze FC findings in a series of pediatric FNAs and to correlate abnormal findings with follow-up information. Materials and Methods: All pediatric FNAs performed at a tertiary-care children's hospital over a 46-month period that had FC performed were retrospectively analyzed and correlated with follow-up. Results: A total of 163 FNA procedures were performed in children (age ≤21 years), and 47 (28.8%) of these cases had FC performed. Specimens were mostly obtained from the head and neck (72.3% of cases). Nine cases (19.1%) had abnormal FC findings, including double-negative T cells (n = 3; 33.3%), double-positive T cells (n = 3; 33.3%), excess λ light chains (n = 1; 11.1%), weak CD34 positivity (n = 1; 11.1%), and T-lymphoblastic lymphoma (n = 1; 11.1%). Conclusion: Unusual FC results that are not diagnostic of malignancy can be seen in lymph node FNA in a minority of young patients. In our series, these findings were seen mainly in small populations of T cells and occurred primarily in the setting of reactive lymphoid hyperplasia or ectopic thymic tissue. Cytopathologists performing FNA on children should be aware of these abnormalities and, although they may warrant further investigation and follow-up, they are unlikely to be associated with malignancy.

Cyclin D1 expression, usually absent in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), has been described in the proliferation centers (PC) of some CLL/SLL. The prevalence of this finding is uncertain, as is the explanation for its occurrence and whether these cases have any other unique features. Cyclin D1 immunohistochemical staining was therefore investigated in 57 extramedullary CLL/SLL biopsies. In 6 cases, cyclin D1 immunofluorescence followed by CCND1 fluorescence in situ hybridization (FISH) and PC targeted analysis was performed using a Bioview Duet system. Excluding the prospectively selected cases that had the targeted FISH studies, cyclin D1+ PC were identified in 20% of cases. The cyclin D1+ CLL did not appear pathologically or phenotypically distinctive, though 46% had an interfollicular growth pattern. The cyclin D1+ PCs were SOX11− and lacked CCND1 translocations and gains in 5 of 5 informative cases. The recognition of cyclin D1 expression in PC of a significant minority of CLL/SLL can be a diagnostic aid and should not lead to the diagnosis of focal mantle cell lymphoma.

This is a case of IgG4-related systemic disease (ISD) and its rare renal manifestation as membranous nephropathy (MGN). The patient presented with peripheral edema, hematuria and proteinuria. 24-h urine revealed proteinuria of up to 15 g/d. Renal biopsy revealed MGN and many IgG4-positive plasma cells. Serum IgG4 levels were elevated at 750 mg/dl (9 - 89 mg/d). Biopsies of multiple tissues revealed many IgG4-positive plasma cells. Prednisone was initiated after making the diagnosis of ISD. However, the patient progressed into renal failure and eventually needed dialysis despite rituximab therapy. The renal manifestation of ISD typically shows tubulointerstitial nephritis, but, rarely, it may include glomerular abnormalities such as MGN or membranoproliferative glomerulonephritis. Castleman disease (CD) and ISD share similarities in pathology, particularly in the lymph nodes. Rituximab has shown promising results in some patients with ISD, CD, and MGN, and its use should be considered in steroid-resistant cases. Clinicians need to be made aware of ISD and its varied presentations. Timely initiation of steroid therapy can induce remission, and delay in therapy can cause permanent organ damage. Therefore, clinicians must have a high index of suspicion to make an early diagnosis of ISD in order to initiate appropriate treatment.

Background: Altered neutrophil maturation patterns have been reported useful for identification of myelodysplastic syndromes (MDS). Methods: Neutrophil maturation patterns based on CD11b, CD13, and CD16 were visually and numerically evaluated in 19 control, 23 MDS, 37 nondiagnostic for MDS (NDM) specimens, and 19 also processed 1 and 2 days subsequently. Results: In contrast to maturation patterns illustrated previously by others as “normal,” 84% of controls displayed diminished acquisition of CD16, imparting a contracted appearance. Such divergence from published “normal” patterns was usually mild-moderate, considered nonspecific, and associated with delayed processing: longer intervals between collection and processing (median 20.5 vs. 5.2 h), and following 1 and 2 days delay. Findings restricted to nonspecific contraction were found in 56% MDS and 78% NDM specimens. Evaluation for aberrant patterns was still performed with mild-moderate contraction present, but concern for over interpretation led to use of an equivocal-aberrant category. Nine cases had aberrant or equivocal-aberrant patterns (seven MDS, two NDM) with distinct visual alterations that differed from nonspecific contraction and had numerical evidence for a left shift: myeloblasts increased (67%) and least mature neutrophils (CD11b-/low, CD16-/low) increased (78%). Although evidence for a left shift was associated with MDS, it was also seen in NDM specimens with a synchronous left shift. Conclusions: Neutrophil maturation patterns that diverge from previously illustrated “normal” patterns, not specific for MDS, may be common in some settings. Laboratories seeking to implement FC evaluation for MDS must determine which findings have sufficient specificity for MDS within their own practice and patient population. © 2012 International Clinical Cytometry Society

Diagnostic hematopathology requires a multiparametric approach and integration of morphologic findings with the clinical, immunophenotypic, and other features. As hematopathology moves into an increasingly digital era, internet-deployed teaching sets consisting of whole slide images (WSI) and comprehensive ancillary information can help prepare hematopathology trainees for the future. Approximately 200 hematopathology conference cases over a 1-year period were de-identified, and case information (including clinical, microscopic and immunophenotypic features, flow cytometric histograms, and cytogenetic and molecular results) were entered into a database. Approximately 1,800 WSI were prepared by scanning using ×40 magnification, and WSI and supplemental data were stored on separate servers and referenced in the database via hyperlinks. From January 2009 to November 2011, the website has been accessed over 6,000 times. The user can view the list of cases and brief clinical history, with or without the diagnosis displayed. Once a case is chosen, the complete clinical history, WSI, case data, and other hyperlinks are displayed, and the user can also scroll down to see the diagnosis shown at the end of the case. Pre- and post-test evaluations are available for self-assessment. The hematopathology virtual set is emerging as an important tool in hematopathology education. The internet-deployed database is unique in the wide range of ancillary studies readily accessible, which reinforces the multiparametric approach in hematopathology.

Background: Flow cytometric immunophenotyping has an established role in the diagnosis and monitoring of B-lymphoblastic leukemia (B-LL). However, the search continues for an optimal reagent set that can identify leukemic blasts with specificity, reproducibility, and sensitivity, at any point during the course of the disease and in every specimen type. Methods: This study evaluated the diagnostic utility of detecting the intracytoplasmic antigens zetaassociated protein (ZAP-70) and Bcl-2 in the distinction between the leukemic blasts of B-LL and hematogones. Results: In comparison with hematogones in reference specimens, significantly higher levels of Bcl-2 were identified in 21 of 23 (91%) B-LL. In particular, Bcl-2 expression was consistently higher in leukemic blasts with bright intensity CD10 expression than the equivalent most immature (CD10 bright intensity) hematogones. As previously reported, Bcl-2 expression was lower in B-LL with BCR-ABL1 gene rearrangement, but the fluorescence intensity of this group of specimens was still significantly higher than that seen for hematogones. In contrast, ZAP-70 was expressed at significantly higher levels in only 7 of 23 (30%) B-LL and demonstrated other findings that might limit clinical utility, including differences in the level of ZAP-70 expression during therapy and between blasts in the peripheral blood and bone marrow. Conclusions: Bcl-2 over-expression provides a useful tool for the distinction between B-LL and hematogones. In contrast, although further optimization of the ZAP-70 assay might increase the sensitivity of detection, over-expression of ZAP-70 was identified in only a minority of B-LL. V C 2011 International Clinical Cytometry Society Key terms: B lymphoblastic leukemia; flow cytometry; Bcl-2; ZAP-70

Flow cytometric immunophenotyping (FCI) is recommended in the evaluation of cerebrospinal fluid (CSF) specimens for hematologic neoplasms. This study reviewed FCI of CSF specimens collected for primary diagnosis (n = 77) and follow-up for known malignancy (n = 153). FCI was positive in 11 (4.8%) of 230 specimens: acute myeloid leukemia, 6; precursor B-acute lymphoblastic leukemia, 2; B-cell lymphoma, 2; and T-cell lymphoma, 1. Positive results were obtained in low-cellularity specimens, including 2 with fewer than 100 events in the population of interest. FCI was indeterminate in 19 (8.3%) of 230 specimens, including 3 with only sparse events, 8 with possible artifact (apparent lack of staining, nonspecific or background staining, and aspirated air), and 8 with phenotypic findings considered insufficient for diagnosis. Indeterminate specimens were often limited by low cellularity and lacked normal cell populations to evaluate for appropriate staining. FCI may be of value in low-cellularity CSF specimens, although the results should be interpreted with caution.