Outcomes of allogeneic stem cell transplantation in hepatosplenic T-cell lymphoma

Hepatosplenic T-cell lymphoma (HSTCL) is a rare but aggressive type of non-Hodgkin lymphoma that primarily involves the sinusoids of the liver, red pulp of the spleen and the sinuses of the bone marrow. The specific rearrangement of the expressed T-cell receptor chain genes (TCR-αβ vs γδ) determines the subtype of the disease (HSαβTCL vs HSγδTCL). HSαβTCL is the rarer subtype with fewer than 30 cases reported in the literature. HSγδTCL is classically described in patients with inflammatory bowel disease treated with azathioprine, those on chronic immunosuppression following solid organ transplantation, and patients treated with TNF-α inhibitors. On the other hand, most reported cases of HSαβTCL do not seem to have an underlying immune-related condition. Hepatosplenomegaly, cytopenias and stage IVB diseases are typical. Common cytogenetic abnormalities include isochromosome 7q and trisomy 8, and neoplastic T cells are usually CD4CD8. HSTCL has a tendency to affect younger individuals with a median age of 20–30 years. Whereas males are significantly more commonly affected with the γδ subtype (male:female (M:F) ratio of 10:1), the αβ subtype has a slight female preponderance (F:M ratio of 1.5:1). Without allogeneic stem cell transplantation (allo-SCT), HSTCL is an almost invariably fatal disease characterized by chemorefractoriness, unremitting