gammadelta Hepatosplenic T-Cell Lymphoma in a Pediatric Patient With Crohn's Disease on Combined Immunosuppressive and Immunomodulator Therapy

摘要

Hepatosplenic T-cell lymphoma (HTCL) is a rare extranodal lymphoma arising from cytotoxic gammadelta or rarely alphabeta T cells of the splenic pool. The disease is characterized by predominance in young, usually male patients and an aggressive clinical course. Hepatosplenic involvement tends to be a constant, and systemic lymphadenopathy is minimal or not seen. Although diagnosis is classically established on histopathology of liver biopsy, the bone marrow is frequently involved and can offer a rapid, less invasive workup for initial diagnosis. The pattern of involvement is distinctive, with a propensity of tumor cells for the marrow sinuses with eventual spillover into the bone marrow interstitium and peripheral blood. The diagnosis can be subtle in earlier stages of the disease, which necessitates primarily considering the diagnosis as well as knowledge of the histologic, immunophenotypic and molecular/genetic features of the disease. Clinical information can be particularly valuable as almost a quarter of HTCLs arise in the setting of chronic immune suppression with data to suggest an association-between this lymphoma and patients with inflammatory bowel disease receiving certain types and combinations of drug therapy. The multifaceted approach to the diagnosis of HTCL in the bone marrow and blood is discussed, as reported from a pathologist's perspective, in a young patient being treated for Crohn's disease.