Composite Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma and Mantle Cell Lymphoma; Small Cell Variant: A Real Diagnostic Challenge. Case Presentation and Review of Literature
Challenging differential diagnosis, Educational Purpose (only if useful for a systematic review or synthesis), Rare co-existance of disease or pathology
Feryal Ibrahim, Ahmad Al Sabbagh, Aliaa Amer, Dina S. Soliman, Hesham Al Sabah
Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research (NCCCR), Hamad Medical Corporation, Doha, Qatar
Am J Case Rep 2020; 21:e921131
Available online: 2020-01-28
Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and mantle cell lymphoma (MCL) both have a common origin arising from mature CD5+ B-lymphocytes. Their distinction is crucial since MCL is a considerably more aggressive disease. Composite lymphoma consisting of CLL/SLL and MCL has been rarely reported. This type of composite lymphoma may be under-diagnosed as the 2 neoplasms have many features in common, both morphologically and immunophenotypically.
CASE REPORT: We report the case of a 57-year-old male patient who presented with a 4-month history of recurrent abdominal pain and distention with hepatosplenomegaly. Peripheral blood showed a high leukocytes count (46.7×10³/uL) with marked lymphocytosis of 35.0×10³/uL, mostly small mature-looking, with some showing nuclear irregularities, with approximately 3% prolymphocytes. Immunophenotyping by flow cytometry and immunohistochemistry revealed 2 immunophenotypically distinct abnormal CD5+monotypic B-cell populations. Fluorescence in situ hybridization (FISH) on peripheral blood demonstrated IGH/CCND1 rearrangement consistent with t(11;14) in 65% of cells analyzed. Accordingly, based on compilation of findings from morphology, flow cytometry, immunohistochemistry, and FISH, A diagnosis of composite lymphoma consisting of MCL; small cell variant and CLL/SLL was concluded.
CONCLUSIONS: We describe a case of composite lymphoma of MCL (small cell variant) and CLL/SLL that emphasizes the crucial role of the multiparametric approach, including vigilant cyto-histopathologic examination, immunophenotyping by flow cytometry and immunohistochemistry, as well as genetic testing, to achieve the correct diagnosis.
Keywords: Composite Lymphoma, Leukemia, Lymphocytic, Chronic, B-Cell, Lymphoma, Mantle-Cell