Concordance among hematopathologists in classifying blasts plus promonocytes: A bone marrow pathology group study.

Enumeration of blasts and promonocytes is essential for World Health Organization (WHO) classification of myelomonocytic neoplasms. The accuracy of distinguishing blasts, promonocytes and monocytes, including normal vs abnormal monocytes, remains controversial. The objective of this analysis is to assess concordances between experienced hematopathologists in classifying cells as blasts, promonocytes, and monocytes according to WHO criteria. Each of 11 hematopathologists assessed glass slides from 20 patients [12 with chronic myelomonocytic leukemia (CMML) and 8 with acute myeloid leukemia (AML)] including blood and BM aspirate smears, and limited nonspecific esterase (NSE) stains. All cases were blindly reviewed. Fleiss' extension of Cohen's kappa for multiple raters was used on these variables, separately for peripheral blood (PB) and bone marrow (BM). Spearman's rank correlation was used to assess correlations between each pair of hematopathologists for each measurement. For the classification based on the sum of blasts and promonocytes in the BM, Fleiss' kappa was estimated as 0.744. For PB, categorizing patients according to the sum of blasts and promonocytes, Fleiss' kappa was estimated as 0.949. Distinction of abnormal monocytes from normal monocytes in PB did not achieve a good concordance and showed strong evidence of differences between hematopathologists (P < .0001). The hematopathologists achieved a good concordance rate of 74% in CMML vs AML classification and a high k rate, confirming that criteria for defining the blasts equivalents (blasts plus promonocytes) could be applied consistently. Identification of monocyte subtypes (abnormal vs normal) was not concordant. Our results support the practice of combining blasts/promonocytes into a single category.

Myeloid Neoplasms with Germline Predisposition: A New Provisional Entity Within the World Health Organization Classification.

The forthcoming update of the World Health Organization (WHO) classification of hematopoietic neoplasms will feature "Myeloid Neoplasms with Germline Predisposition" as a new provisional diagnostic entity. This designation will be applied to some cases of acute myeloid leukemia and myelodysplastic syndrome arising in the setting of constitutional mutations that render patients susceptible to the development of myeloid malignancies. For the diagnostic pathologist, recognizing these cases and confirming the diagnosis will demand a sophisticated grasp of clinical genetics and molecular techniques. This article presents a concise review of this new provisional WHO entity, including strategies for clinical practice.

Lymphocytosis, lymphadenopathy: benign or malignant?

The increasing use of immunophenotypic and molecular analysis in the routine evaluation of patients with lymphocytosis, lymphadenopathy, or other hematologic disorders has led to the identification of unexpected small clonal lymphoid populations. These clones, sometimes with disease-specific markers, such as the t(14;18), are especially challenging for the clinician because of their unknown biologic potential and uncertain clinical behavior. Study of these early lymphoid lesions is providing important clues to the process of lymphomagenesis, and may provide the rationale for preemptive therapy in the future. More and more, the hematologist/oncologist is consulted regarding otherwise healthy individuals with lymphadenopathy and/or lymphocytosis, and pathology reports that confound the referring internist or surgeon. The report does not name a malignant lymphoproliferative disorder, but is not completely "normal". Does the patient have a benign or malignant condition? How should they be evaluated? Is treatment indicated? These patients prove challenging for the consulting hematologist as well as the referring physician. In this review, we will focus on some of these scenarios and attempt to provide guidance for their management.

GATA family transcriptional factors: emerging suspects in hematologic disorders.

GATA transcription factors are zinc finger DNA binding proteins that regulate transcription during development and cell differentiation. The three important GATA transcription factors GATA1, GATA2 and GATA3 play essential roles in the development and maintenance of hematopoietic systems. GATA1 is required for the erythroid and megakaryocytic commitment during hematopoiesis. GATA2 is crucial for the proliferation and survival of early hematopoietic cells, and is also involved in lineage specific transcriptional regulation as the dynamic partner of GATA1. GATA3 plays an essential role in T lymphoid cell development and immune regulation. As a result, mutations in genes encoding the GATA transcription factors or alteration in the protein expression level or their function have been linked to a variety of human hematologic disorders. In this review, we summarized the current knowledge regarding the disrupted biologic function of GATA in various hematologic disorders.

Flow cytometric analysis of lymphoid enhancer-binding factor 1 in diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma.

OBJECTIVES: Nuclear overexpression of lymphoid enhancer-binding factor 1 (LEF1) assessed by immunohistochemistry has been shown to be highly associated with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) among small B-cell lymphomas. The purpose of this study was to evaluate the utility of flow cytometric analysis of LEF1 in the diagnosis of CLL/SLL. METHODS: Normal peripheral blood was used to validate the test. Flow cytometric analysis of LEF1 was performed in 64 patient samples qualitatively and quantitatively by comparing the staining intensity and the ratios of the median fluorescence intensities (MFIs) of LEF1 in B cells of interest to the internal reference cell populations. The results were correlated with the pathologic diagnosis. RESULTS: Proper sample processing ensured sufficient separation of positive LEF1 staining in T cells from negative staining in normal B and natural killer (NK) cells. Qualitative analysis of patient samples showed that all 25 cases of CLL/SLL but none of the other small B-cell lymphomas were positive for LEF1. Using a B/NK MFI ratio of 1.5 and B/T MFI ratio of 0.45 separated CLL/SLL cases from non-CLL lymphomas. CONCLUSIONS: Flow cytometric analysis of LEF1 is sufficient to differentiate CLL/SLL from other small B-cell lymphomas and may serve as a useful tool in the diagnosis of CLL/SLL.

Phase II study of alemtuzumab-rituximab therapy in previously untreated patients with chronic lymphocytic leukemia: short- and long-term outcomes.

We investigated the safety, efficacy, and long-term outcomes of alemtuzumab and rituximab (AR) combination therapy in previously untreated patients with CLL. Thirty patients, ages 28-80 years, 47% older than 60 years, 90% Rai clinical stages II-IV, and 67% without favorable cytogenetics received AR. Based on the NCI-WG 1996 criteria, OR was 100%, with 60% CR. With CT scans OR was 70%, with 23% CR, 47% PR, and 30% SD. Sixty-seven percent of patients showed no evidence of MRD in the bone marrow by 6-color flow cytometry. Median PFS, TFS, and 5-year OS were 24.4, 50.7 months, and 80%, respectively. Grade 3/4 neutropenia and thrombocytopenia were reported in 30% and 7% of patients, respectively. CMV reactivation, asymptomatic in all but one patient, occurred in 8 patients. Immunotherapy with alemtuzumab and rituximab results in robust responses and long asymptomatic therapy-free intervals. It is well tolerated with infrequent, predictable, and easily managed complications.

Heritable GATA2 mutations associated with familial AML-MDS: a case report and review of literature.

A 50-year-old woman was diagnosed with acute myeloid leukemia (AML). She has history of thrombocytopenia for 25 years and a significant family history of thrombocytopenia, affecting her mother, siblings and their children, as well as her own children. Both her mother and maternal aunt died from myelodysplastic syndrome (MDS). Additional genetic analysis was performed and identified two heterozygous missence mutations in the second zinc finger domain of GATA2 gene (p.Thr358Lys, and p.Leu359Val), occurring in cis on the same allele. Given the patient's family history and clinical manifestation, this was interpreted as an acute myeloid leukemia with heritable GATA2 mutations associated with familial AML-MDS. Germline GATA2 mutations are involved in a group of complex syndromes with overlapping clinical features of immune deficiency, lymphedema and propensity to acute myeloid leukemia or myelodysplastic syndrome (AML-MDS). Here we reported a case of familial AML-MDS with two novel GATA2 mutations. This case illustrates the importance of recognizing the clinical features for this rare category of AML-MDS and performing the appropriate molecular testing. The diagnosis of heritable gene mutations associated familial AML-MDS has significant clinical implication for the patients and affected families. Clinical trials are available to further investigate the role of allogeneic hematopoietic stem cell transplant in managing these patients.

Bone marrow involvement by subcutaneous panniculitis-like T-cell lymphoma: a report of three cases.

Subcutaneous panniculitis-like T-cell lymphoma is a rare subtype of cutaneous T-cell lymphoma. Virtually all cases are confined to the subcutaneous adipose tissue. In this report, we describe the first small series of subcutaneous panniculitis-like T-cell lymphoma (three patients) with bone marrow involvement. All patients presented with skin or soft tissue nodules, fever, and constitutional symptoms, and were diagnosed with subcutaneous panniculitis-like T-cell lymphoma based on the characteristic morphologic and immunophenotypic features of the subcutaneous lesions. Bone marrow core biopsies in these cases showed focal involvement by lymphoma with pathologic features similar to those seen in the diagnostic biopsies. Our observations suggest bone marrow involvement by subcutaneous panniculitis-like T-cell lymphoma does occur, and can be identified histologically and confirmed using standard immunohistochemistry. Our findings raise awareness of bone marrow involvement in this rare entity. However, the incidence and significance of bone marrow involvement in subcutaneous panniculitis-like T-cell lymphoma requires further evaluation.

Administration of ATRA to newly diagnosed patients with acute promyelocytic leukemia is delayed contributing to early hemorrhagic death.

We hypothesized that the high early death rate (EDR) due to bleeding in acute promyelocytic leukemia (APL) is in part attributable to delays in all- trans retinoic acid (ATRA). We conducted a retrospective analysis of the timing of ATRA administration. 204 consecutive patients with newly diagnosed APL between 1992 and 2009 were identified. The EDR was 11%. 44% of early deaths occurred in the first week. Hemorrhage accounted for 61% of early deaths. ATRA was ordered the day APL was suspected in 31% of patients. Delays in ATRA administration led to increases in the percentage of early deaths from hemorrhage.

Nuclear protein dysregulation in lymphoplasmacytic lymphoma/waldenstrom macroglobulinemia.

Waldenström macroglobulinemia (WM) is characterized by monoclonal gammopathy, usually IgM, in association with lymphoplasmacytic lymphoma (LPL). Little is known of the expression of nuclear proteins involved in B-cell development in LPL/WM. In this study, the expression patterns of PAX5/BSAP, MUM1/IRF4, and PRDM1/BLIMP1 were analyzed in plasma cells and lymphocytes in 29 cases of newly diagnosed LPL/WM by double immunohistochemical staining with CD138 and CD22. These patterns were compared with the expression profiles seen in normal bone marrow samples, reactive tonsils, and cases of plasma cell myeloma and marginal zone lymphoma. The median percentage of plasma cells coexpressing CD138 and PAX5 was significantly higher in LPL/WM compared with benign tissues (P = .001), marginal zone lymphoma (P = .002), and plasma cell myeloma (P < .0001), whereas the median percentage of plasma cells coexpressing CD138 and MUM1 was lower in LPL/WM than plasma cells in benign tissues (P = .02), marginal zone lymphoma (P = .001), and plasma cell myeloma (P = .0002). These findings show that a subset of plasma cells in LPL/WM demonstrates a nuclear protein expression pattern characteristic of the B-cell developmental program. Thus, the results better define the immunophenotypic profile of the neoplastic cells in LPL/WM.

Nuclear expression of sox11 is highly associated with mantle cell lymphoma but is independent of t(11;14)(q13;q32) in non-mantle cell B-cell neoplasms.

Sox11 is a transcription factor involved in embryonic neurogenesis and tissue remodeling. Its role in lymphopoiesis is presently unknown. Recent studies have shown the nuclear expression of sox11 in mantle cell lymphoma, which raises the question about its possible association with t(11;14)(q13;q32), the genetic hallmark of mantle cell lymphoma leading to the overexpression of cyclin D1. In this study, we examined sox11 expression in 211 cases of B-cell neoplasms by immunohistochemistry, and evaluated its association with t(11;14) and overexpression of cyclin D1. Nuclear staining of sox11 was observed in 54 of 57 (95%) mantle cell lymphomas, including 52 of 53 (98%) classical and 2 of 4 variant types. Two of the three mantle cell lymphomas negative for nuclear sox11 staining were analyzed and were positive for t(11;14). All other B-cell lymphomas (114 cases) showed variable positive staining in the cytoplasm, but no nuclear positivity. Sox11 was then examined in plasma cell myeloma and hairy cell leukemia as a subset of plasma cell myeloma carry t(11;14) and overexpress cyclin D1, and cyclin D1 is overexpressed in a subset of hairy cell leukemia independent of t(11;14). We found no nuclear staining of sox11 in 30 plasma cell myelomas examined, including 12 cases with t(11;14)(q13;q32). It is interesting that intense nuclear staining of sox11 was present in a subset of hairy cell leukemias (5 of 10), and was associated with the overexpression of cyclin D1. Our results indicate that the nuclear expression of sox11 is highly associated with mantle cell lymphoma, but is independent of t(11;14)(q13;q32) in non-mantle cell B-cell neoplasms. Its association with the overexpression of cyclin D1 in hairy cell leukemia suggests that sox11 may be involved in the upregulation of cyclin D1 in this leukemia.

Primary mediastinal large B-cell lymphoma in HIV: report of two cases.

Primary mediastinal large B cell lymphoma (PMLBCL) is a subtype of diffuse large B cell lymphoma arising in the mediastinum with distinctive clinical and morphological features. Though diffuse large B cell lymphoma is one of the most common non-Hodgkin lymphoma associated with AIDS, there are no data available regarding the association of HIV and PMLBCL. We report here two cases of PMLBCL arising in AIDS patients. In both cases, PMLBCL presented in a setting of low CD4 T-cell count as rapidly enlarging mediastinal mass. The morphologic and immunophenotypic findings are characteristic of PMLBCL. One of the two patients, a 25-year-old woman who had localized disease and evidence of Epstein-Barr virus in lymphoma cells, did not respond to chemotherapy and died of disease progression 5 months after diagnosis. The second patient, a 38-year-old male with disseminated disease, responded to therapy and is disease-free after 9 months of follow-up.

CD23+ mantle cell lymphoma: a clinical pathologic entity associated with superior outcome compared with CD23- disease.

Mantle cell lymphoma (MCL) commonly lacks expression of CD23. However, a significant minority of MCLs express CD23, as assessed by flow cytometric immunophenotyping (FCIP). The aims of our study were to investigate the expression of CD23 by FCIP in patients with MCL and to correlate CD23 expression with pathologic and clinical parameters, including outcome. We studied 53 patients with untreated MCL who had CD23 expression determined by FCIP. At diagnosis, 14 MCLs (26%) were CD23+ at all tissue sites, whereas 33 (62%) were CD23-, and 6 (11%) had discordant CD23 expression among different tissue sites. Patients with CD23- MCL had extranodal disease more commonly compared with patients with CD23+ MCL. Moreover, with 57-month median follow-up, the 4-year event-free and overall survival rates for CD23+ MCL were 45% and 75%, respectively, compared with 19% and 51% for CD23- MCL. In multivariate Cox regression analysis, CD23 status and leukemic-phase MCL were the most important factors predicting outcome.

Instability of immunophenotype in plasma cell myeloma.

Little information has been reported describing antigen stability in plasma cell myeloma. In this study, the expression frequency and stability of 2 potential therapeutic targets, CD20 and CD52, along with the frequently aberrantly expressed CD56 antigen, were evaluated by flow cytometric analyses in 56 patients with plasma cell myeloma. Of the 56 patients, 23 (41%) showed immunophenotype change, including CD56 in 6 cases, CD20 in 7 cases, and CD52 in 17 cases. Combined CD56/CD52 change was seen in 3 cases and combined CD20/CD52 in 4 cases. No correlation was found between immunophenotype change and age, sex, stage, plasma cell morphologic features, extent of marrow involvement, time between analyses, type of therapy, or response to therapy. Immunophenotype shift was more common in patients with IgA than in patients with IgG paraprotein. Recognition of lack of stability in immunophenotype may be important, especially in antigen-directed treatment decisions and when specific phenotypes are used to detect residual disease.

Dysregulated angiogenesis in B-chronic lymphocytic leukemia: morphologic, immunohistochemical, and flow cytometric evidence.

BACKGROUND: The extent of enhanced bone marrow angiogenesis in chronic lymphocytic leukemia (CLL) and relationship to proangiogenic factors and prognostic indicators is largely unexplored. METHODS: To further investigate the role of angiogenesis in CLL by evaluating the topography and extent of angiogenesis in a group of CLL bone marrow biopsies, to study the expression of pro and antiangiogenic vascular factors in CLL cells to more precisely document the cell types producing these factors, and to evaluate the role, if any, of localized hypoxia in upregulation of angiogenesis in CLL We used immunohistochemistry (IHC) (n = 21 pts) with antibodies to CD3 and CD20, proangiogenic (VEGF, HIF-1a) and antiangiogenic (TSP-1) factors, and VEGF receptors -1 and -2 to examine pattern/extent of CLL marrow involvement, microvessel density (MVD), and angiogenic characteristics; flow cytometry (FC) was performed on 21 additional cases for VEGF and TSP-1. RESULTS: CLL patients had higher MVD (23.8 vs 14.6, p~0.0002) compared to controls (n = 10). MVD was highest at the periphery of focal infiltrates, was not enhanced in proliferation centers, and was increased irrespective of the presence or absence of cytogenetic/immunophenotypic markers of aggressivity. By IHC, CLL cells were VEGF(+), HIF-1a (+), TSP-1(-), VEGFR-1(+), and VEGFR-2(+). By FC, CLL cells were 1.4-2.0-fold brighter for VEGF than T cells and were TSP-1(-). CONCLUSION: CLL demonstrates enhanced angiogenesis, with increased MVD, upregulated VEGF and downregulated TSP-1. Upregulation of HIF-1a in all CLL cases suggests localized tissue hypoxia as an important stimulant of microvessel proliferation. The presence of VEGF receptors on CLL cells implies an autocrine effect for VEGF. Differences in MVD did not correlate with traditional genetic/immunophenotypic markers of aggressiveness.

The usefulness of CD26 in flow cytometric analysis of peripheral blood in Sézary syndrome.

The loss of CD26 expression was proposed to be a constant feature of circulating Sézary cells by flow cytometric immunophenotyping (FCIP), but the experience with CD26 is limited. To establish its usefulness, CD26 results were correlated with morphologic, molecular, and immunophenotypic findings. Based on FCIP of 179 samples of peripheral blood, CD26 negativity was found in 59.3% of cases with Sézary syndrome (SS), 33.3% of mycosis fungoides (MF), 14.2% of benign dermatosis (BD), and no control cases. In diagnostic subgroups of SS based on morphologic, molecular, and immunophenotypic criteria, the percentage of CD26- cases varied from 41.1% to 63.6%. The specificity of a CD26- result was inferior to that of T-cell antigen loss in differentiating SS from MF and BD. CD26 offers lower diagnostic performance than previously suggested; however, in addition to the findings of major T-cell antigen loss, it could improve sensitivity of FCIP in patients with SS.

Chronic lymphocytic leukemia FISH panel: impact on diagnosis.

Interphase fluorescence in situ hybridization (FISH) is an alternative to conventional chromosome analysis of chronic lymphocytic leukemia (CLL) cells. We analyzed 172 samples from 136 possible CLL cases using a FISH panel. Reflex testing with probes to CCND1, BCL2, BCL3, BCL11A, c-MYC, MALT1, and a break-apart immunoglobulin heavy chain (IGH) probe was done if more than 2 signals for 14q32 occurred. For 111 cases, there were sufficient data for analysis. Of 111 cases, 81 (72.9%) had 1 or more genetic abnormalities. The most frequent abnormality was 13q-, followed by trisomy 12, 11q-, and 17p-. In 13 cases, there were IGH abnormalities. Two cases with CCND1/IGH fusion were reclassified as mantle cell lymphoma. Four CLL cases had IGH fusion with BCL2, BCL3 (2 cases), and BCL11A; no fusion partner was detected in 7 cases. Morphologic features were atypical for CLL in 2 cases with IGH fusion (BCL11A and BCL3). The FISH CLL panel is useful to identify prognostic aberrations and to clarify diagnosis in cases with unusual morphologic features.

Hereditary pyropoikilocytosis: a rare but potentially severe form of congenital hemolytic anemia.

Hereditary pyropoikilocytosis is an inherited red cell membrane disorder with characteristic morphology: striking anisopoikilocytosis with red cell fragmentation and microspherocytes. Clinical and laboratory physicians must be aware of the potential impact of this disorder on accuracy of complete blood count results reported by automated hematology instruments. Recognition of the morphologic and laboratory findings are important for recognizing this potentially severe anemia.