A 33-year-old man with Crohn disease had been treated with azathioprine for 10 years and azathioprine/adalimumab for 9 months when he began experiencing fevers, fatigue, splenomegaly, and weight loss (20 lb in 6 months). Besides anemia and thrombocytopenia, his peripheral blood and bone marrow aspirate smears showed blastoid cells (panel A; Wright-Giemsa; original magnification ×1000, oil) that were intermediate to large in size and had fine chromatin, prominent nucleoli, and irregular nuclear contours. His bone marrow biopsy was hypercellular with dilated sinuses filled with these blastoid cells (panel B; hematoxylin and eosin; original magnification ×1000, oil]) that were positive for CD3 (panel C; original magnification ×200) and T-cell–restricted intracellular antigen-1, but were negative for granzyme B, T-cell leukemia/lymphoma 1A, and terminal deoxynucleotidyltransferase. Flow cytometry performed on the bone marrow aspirate further characterized them as γ-δ T cells (CD2+/CD4/CD5/CD7+/CD8/CD16+/CD56+/CD94+) with coexpression of killer immunoglobulin-like receptors CD158a and CD158e. Bone marrow cytogenetic study revealed 45,X,-Y,der(2)t(2;8)(q37.3;q13),i(7)(q10)[5]/46,XY[15]. Isochromosome 7q [i(7q)] was confirmed by fluorescence in situ hybridization (FISH) (panel D). The patient was diagnosed with hepatosplenic T-cell lymphoma (HSTCL) and subsequently received CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)–etoposide treatment.

An association between HSTCL and a long-term thiopurine treatment in patients with Crohn disease has been reported. Except for an unusual blastoid morphology of the lymphoma cells, the histology, immunophenotype, and i(7q) are all characteristic for HSTCL.

A 33-year-old man with Crohn disease had been treated with azathioprine for 10 years and azathioprine/adalimumab for 9 months when he began experiencing fevers, fatigue, splenomegaly, and weight loss (20 lb in 6 months). Besides anemia and thrombocytopenia, his peripheral blood and bone marrow aspirate smears showed blastoid cells (panel A; Wright-Giemsa; original magnification ×1000, oil) that were intermediate to large in size and had fine chromatin, prominent nucleoli, and irregular nuclear contours. His bone marrow biopsy was hypercellular with dilated sinuses filled with these blastoid cells (panel B; hematoxylin and eosin; original magnification ×1000, oil]) that were positive for CD3 (panel C; original magnification ×200) and T-cell–restricted intracellular antigen-1, but were negative for granzyme B, T-cell leukemia/lymphoma 1A, and terminal deoxynucleotidyltransferase. Flow cytometry performed on the bone marrow aspirate further characterized them as γ-δ T cells (CD2+/CD4/CD5/CD7+/CD8/CD16+/CD56+/CD94+) with coexpression of killer immunoglobulin-like receptors CD158a and CD158e. Bone marrow cytogenetic study revealed 45,X,-Y,der(2)t(2;8)(q37.3;q13),i(7)(q10)[5]/46,XY[15]. Isochromosome 7q [i(7q)] was confirmed by fluorescence in situ hybridization (FISH) (panel D). The patient was diagnosed with hepatosplenic T-cell lymphoma (HSTCL) and subsequently received CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)–etoposide treatment.

An association between HSTCL and a long-term thiopurine treatment in patients with Crohn disease has been reported. Except for an unusual blastoid morphology of the lymphoma cells, the histology, immunophenotype, and i(7q) are all characteristic for HSTCL.

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