Is speed of healing a good predictor of eventual healing of pyoderma gangrenosum?

BACKGROUND: Pyoderma gangrenosum is a rare inflammatory skin condition. Two prospective studies have evaluated treatments for pyoderma gangrenosum using a primary outcome of healing speed at 6 weeks. OBJECTIVE: Using data from both studies we assessed the predictive value of 3 early predictors for healing at 6 months: speed of healing, Investigator Global Assessment (IGA), and resolution of inflammation, recorded at 2 and 6 weeks. METHODS: Logistic regression models were applied and the effectiveness of the 3 measures was assessed through estimating the positive and negative predictive values and the area under the receiver operating characteristic curve. RESULTS: The positive and negative predictive value at 6 weeks were, respectively, 63.5% (95% confidence interval [CI] 52.4%-73.7%) and 74.6% (95% CI 62.5%-84.5%) for speed of healing; 80% (95% CI 68.7%-88.6%) and 74.2% (95% CI 64.1%-82.7%) for IGA; and 72.1% (95% CI 59.9%-82.3%) and 68.1% (95% CI 57.7%-77.3%) for resolution of inflammation. IGA had the best combined positive predictive value, negative predictive value, and area under the receiver operating characteristic curve at 2 and 6 weeks. LIMITATIONS: We were limited by data available from existing datasets. CONCLUSION: Speed of healing, IGA, and resolution of inflammation were all shown to be good predictors of eventual healing of pyoderma gangrenosum.

Clinical outcomes and response of patients applying topical therapy for pyoderma gangrenosum: A prospective cohort study.

BACKGROUND: Pyoderma gangrenosum (PG) is an uncommon dermatosis with a limited evidence base for treatment. OBJECTIVE: We sought to estimate the effectiveness of topical therapies in the treatment of patients with PG. METHODS: This was a prospective 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. RESULTS: 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. LIMITATIONS: Our study did not include a randomized comparator. CONCLUSION: 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.

Fatal Case of Primary Cutaneous Aggressive T-Cell Lymphoma Switching From a CD4+ to a CD8+ Phenotype: Progressive Disease With Bexarotene and Romidepsin Treatment.

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.

Evaluation of Novel Targets, Including CC-Chemokine Receptor 4, in Adult T-Cell Acute Lymphoblastic Leukemia/Lymphoma: A Mayo Clinic Clinical and Pathologic Study.

CONTEXT.­: Unlike B-cell acute lymphoblastic leukemia/lymphoma (ALL/LBL), there have been few therapeutic advances in T-cell ALL (T-ALL)/LBL, an aggressive ALL/LBL subtype. OBJECTIVE.­: To perform a focused tissue array study to elucidate tumor markers of therapeutic potential in T-ALL/LBL. DESIGN.­: Using immunohistochemistry, we evaluated expression of leukemic antigens of interest, specifically CC-chemokine receptor 4 (CCR4), among others, on available remnant diagnostic material, including tumor tissue slides obtained from formalin-fixed, paraffin-embedded preserved tissues. RESULTS.­: Our analysis identified, for the first time, expression of CCR4 in T-ALL/LBL in 11 of 27 cases (40.7%) and confirmed common expression of BCL2, CD38, and CD47, as reported previously. We also identified the expression of CD123 in 4 of 26 cases (15.4%), whereas BCL6 and PDL1 were expressed in a small number of T-ALL/LBL cases. The potential novel target CCR4 was significantly more common in the Pre/Pro-T immunophenotypic subtype, 6 of 9 (66.7%, P = .01). No additional differences in clinical and epidemiologic variables were noted among positive or negative CCR4 cases. CONCLUSIONS.­: These findings support preclinical and clinical testing of therapies targeting CCR4, CD47, BCL2, CD38, and CD123 in T-ALL/LBL, and may help guide the development of targeted clinical trials in T-ALL/LBL, a rare disease in urgent need of novel therapies.

Rapid Expansion of a Teledermatology Web Application for Digital Dermatology Assessment Necessitated by the COVID-19 Pandemic: Retrospective Evaluation.

BACKGROUND: The COVID-19 pandemic necessitated a change in the provision of outpatient care in dermatology. OBJECTIVE: A novel, asynchronous, digital consultation platform was codeveloped with 2 National Health Service dermatology teams to improve access and enhance choice in outpatient care. METHODS: The rollout of the platform was accelerated during the initial COVID-19 lockdown, and its wider use across 2 Scottish health boards was retrospectively evaluated. Integrated with the hospital booking system and electronic patient record, the platform provides an alternative to face-to-face consultations, using information and images submitted by the patients. RESULTS: In total, 297 new patient consultations and 108 return patient consultations were assessed, and 80% (324/405) of the images submitted were of satisfactory quality. The consultations were, on average, 3 minutes shorter than equivalent face-to-face interactions, and a total of 5758 km of patient travel was avoided. Outcomes included web-based reviews (66/405, 16.3%), face-to-face reviews (190/405, 46.9%), biopsies (46/405, 11.4%), discharge (89/405, 22%), and other treatments or investigations (14/405, 3.5%). High levels of patient satisfaction (92/112, 82.1%) were reported. CONCLUSIONS: Digital dermatology assessments are now included in the choices for consultation types that are available to patients, helping to augment service capacity during pandemic recovery.

Rare Multisystem Histiocytic Sarcoma on 18F-FDG PET/CT.

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. 18F-FDG PET/CT is a valuable tool in staging this rare entity and in assessing the response to therapy. Knowing the diverse metastatic pattern of HS will help avoid imaging pitfalls on clinical 18F-FDG PET/CT scans.

The Role and Pitfall of F18-FDG PET/CT in Surveillance of High Grade Pulmonary Lymphomatoid Granulomatosis.

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.

Utility of TRBC1 Expression in the Diagnosis of Peripheral Blood Involvement by Cutaneous T-Cell Lymphoma.

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 ß chains, TRBC1 and TRBC2. Analysis of CD4+ T-cell subsets and TCR variable ß 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.

Flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: International guidelines for assay characteristics.

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.

International guidelines for the flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: Assay development/optimization, validation, and ongoing quality monitors.

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.

Determination of immunophenotypic aberrancies provides better assessment of peripheral blood involvement by mycosis fungoides/Sézary syndrome than quantification of CD26- or CD7- CD4+ T-cells.

BACKGROUND: 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. 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 < .001) between the EORTC/ISCL method and FCI method; however, four (6.5%) patients would have an altered B stage between B0 and B1. CONCLUSION: 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.

Reactive Eosinophil Proliferations in Tissue and the Lymphocytic Variant of Hypereosinophilic Syndrome.

OBJECTIVES: The 2019 Society for Hematopathology and European Association for Haematopathology Workshop reviewed the spectrum of neoplastic, nonneoplastic, and borderline entities associated with reactive eosinophilia in tissue. METHODS: The workshop panel reviewed 46 cases covered in 2 workshop sessions. RESULTS: The 46 cases were presented with their consensus diagnoses during the workshop. Reactive eosinophilia in lymph nodes and other tissues may be accompanied by or be distinct from peripheral blood eosinophilia. Reactive etiologies included inflammatory disorders such as Kimura disease and IgG4-related disease, which may show overlapping pathologic features and reactions to infectious agents and hypersensitivity (covered in a separate review). Hodgkin, T-cell, and B-cell lymphomas and histiocytic neoplasms can result in reactive eosinophilia. The spectrum of these diseases is discussed and illustrated through representative cases. CONCLUSIONS: Reactive eosinophilia in lymph nodes and tissues may be related to both nonneoplastic and neoplastic lymphoid proliferations and histiocytic and nonhematolymphoid processes. Understanding the differential diagnosis of reactive eosinophilia and the potential for overlapping clinical and pathologic findings is critical in reaching the correct diagnosis so that patients can be treated appropriately.

Myeloid/Lymphoid Neoplasms Associated With Eosinophilia and Rearrangements of PDGFRA, PDGFRB, or FGFR1 or With PCM1-JAK2.

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.

Mastocytosis.

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.

Eosinophilia/Hypereosinophilia in the Setting of Reactive and Idiopathic Causes, Well-Defined Myeloid or Lymphoid Leukemias, or Germline Disorders.

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.

Breast Implant-Associated Anaplastic Large-Cell Lymphoma: Current Understanding and Recommendations for Management.

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.

Bone Marrow Aspiration and Biopsy Performed by RNs: A Review of Clinical Practice.

: 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.

The current role of clinical flow cytometry in the evaluation of mature B-cell neoplasms.

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.