A Case of Synchronous Bone Marrow Chronic Myelomonocytic Leukemia (CMML) and Nodal Marginal Zone Lymphoma (NMZL).

BACKGROUND Leukemias and lymphomas can arise from myeloid or lymphoid stem cells. Combined myeloid leukemia and non-Hodgkin's lymphoma (NHL), either synchronous or metachronous, rarely occur in the same patient. This report is of a 67-year-old man with a synchronous diagnosis of both bone marrow chronic myelomonocytic leukemia (CMML) and nodal marginal zone lymphoma (NMZL), which a peripheral low-grade B-cell NHL. CASE REPORT A 67-year-old Caucasian man, who was a long-term cigarette smoker, presented with a five-year history of leukocytosis and cervical lymphadenopathy. He had no symptoms of night sweats, fever, or weight loss. Review of his medical records showed a progressively increasing leukocytosis with a peak of 58×109/L. Computed tomography (CT) imaging of the chest and abdomen showed lymphadenopathy, including enlarged cervical, axillary, mediastinal, and retroperitoneal lymph nodes. Bone marrow biopsy and histology showed CMML. Lymph node biopsy and histology showed NMZL. The patient was treated for NMZL with weekly intravenous rituximab infusions. Although his CMML was stable, the patient requested an evaluation for treatment with hematopoietic allogeneic stem cell transplantation (ASCT). At the time of this report, the patient remains asymptomatic. CONCLUSIONS The synchronous occurrence of bone marrow CMML and NMZL in a single patient is rare and may be attributed to a genetic mutation common to both. There are no current treatment guidelines for this group of patients, and treatment strategies should be individualized to provide an optimum outcome or symptomatic improvement.

Bcl-2 maturation pattern in T-cells distinguishes thymic neoplasm/hyperplasia, T-lymphoblastic lymphoma, and reactive lymph nodes.

Anterior mediastinal biopsies consisting predominantly of small lymphocytes can be a diagnostic challenge, especially in small core biopsies. In these cases, immunophenotyping is often employed using flow cytometry, and/or immunohistochemistry. However, due the overlap in T-cell phenotype between thymic neoplasm/hyperplasia (THY), T-lymphoblastic lymphoma (T-LBL), and reactive lymph nodes (RLN), biopsies consisting predominantly of T-cells may still be difficult to differentiate. Previous studies have shown a specific CD3/bcl-2 staining pattern in thymic T cells of humans and mice using flow cytometry. However, the utility of this finding in distinguishing T-cells of THY, T-LBL, and RLN has not been carefully evaluated. Our findings show that the pattern of CD3/bcl-2 expression in thymic T-cells can be used to help diagnose anterior mediastinal biopsies, even when limited specimen is provided. © 2017 International Clinical Cytometry Society.

Interdigitating dendritic cell sarcoma.

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare dendritic cell tumor with slightly more than 100 cases reported in the English literature. This report discusses a case of localized IDCS involving cervical lymph nodes and provides a literature review of clinicopathologic aspects and treatment outcomes.

Correlation of FLT3 mutations with expression of CD7 in acute myeloid leukemia.

FLT3 mutations are common in acute myeloid leukemia (AML), particularly in cases with normal karyotype. Internal tandem duplication (ITD) and also point mutations affecting aspartic acid 835 (D835) are reported. A previous study demonstrated aberrant expression of CD7 on blasts in de novo AML cases with FLT3/ITD mutations. Our study goals are to expand the evaluation of this association to a larger group of patients; to evaluate the association of aberrant CD7 expression in AMLs with D835 mutation, not previously done; to evaluate if aberrant CD7 expression may serve as a surrogate marker for predicting FLT3 mutational status; to evaluate if combined FLT3 with NPM1 mutational status has a better correlation with CD7 expression. The FLT3 mutational analysis was performed on DNA extracted from 149 previously diagnosed AML cases with cytogenetics and flow cytometry evaluation available. Of 149 patients, 28 were positive for FLT3; CD7 was positive in 13 of 20 ITD-positive cases, 5 of 6 D835-positive cases, and 1 of 2 ITD/D835-positive cases. The association of CD7 positivity and FLT3 positivity was found to be significant. However, CD7 expression has a low positive predictive value of 30% and a negative predictive value of 90%. Because of the low positive predictive value, CD7 expression cannot be used as a surrogate marker for FLT3 positivity; even though the negative predictive value is higher, some cases that are FLT3 positive may be missed if CD7 expression would be used for screening.