[1289] Composite Hematolymphoid Neoplasms in Bone Marrow: A Ten-Year Retrospective Analysis

EL Boswell, E Wang. Duke University Medical Center, Durham, NC

Background: Composite hematolymphoid neoplasms are infrequently seen in bone marrow. The existing literature is limited to case reports and small case series, with most describing the coexistence of indolent B-cell and myeloid neoplasms. The incidence, clinicopathologic spectrum and pathogenesis of these composite neoplasms have not yet been established.
Design: Bone marrow biopsies which exhibited two hematolymphoid neoplasms were identified by a retrospective electronic records search, and review of the concurrent clinical histories was performed.
Results: Forty-four bone marrows with two distinct hematolymphoid neoplasms were identified; patients ranged in age from 42 to 91 (median 64). Male patients represented 36 (82%) of cases. Eighteen cases (40.9%) had a prior history of chemotherapy for hematolymphoid neoplasms; the primary treatment indications were plasma cell myeloma (8 cases), B-cell lymphomas (7 cases), and myeloid neoplasms (3 cases). Secondary diagnoses in the subset of patients with prior chemotherapy included myelodysplastic syndrome (9 cases), myeloproliferative neoplasm (5 cases), plasma cell myeloma (3 cases) and chronic lymphocytic leukemia (CLL; 1 case). The remaining 26 cases presumably represent primary composite hematolymphoid neoplasms. These included coexistent myeloid neoplasm and chronic lymphocytic leukemia (7 cases), myeloid and non-CLL B-cell neoplasm (4 cases), myeloid and plasma cell neoplasm (4 cases), plasma cell neoplasm and CLL (3 cases), systemic mastocytosis with associated non-mast cell hematologic malignancy (2 cases) and others (6 cases). Cytogenetic studies and/or immunophenotypic analyses in some cases suggest a distinctive clonal origin between the two coexisting neoplasms.
Conclusions: Composite hematolymphoid neoplasms were primarily observed in older patients and have a male predominance. Approximately one-third of the cases were associated with prior treatment for primary hematolymphoid neoplasms, raising the possibility of therapy-related secondary neoplasms. The most common primary diagnosis was myeloid neoplasm with a B-cell/plasma cell neoplasm, followed by plasma cell neoplasm with CLL. The incidence of dual marrow neoplasms was greater than suggested by chance alone, though the exact pathogenic mechanisms remain to be further investigated.
Category: Hematopathology

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 181, Wednesday Afternoon


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