Hepatosplenic T-Cell Lymphoma: A Population-Based Study Assessing Incidence and Association With Immune-Mediated Disease.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare malignancy of unknown incidence that has been associated with immune-mediated disease. This study explored the incidence and patient characteristics of HSTCL in a population of 15.5 million over a 13-year period using a comprehensive national pathology database in The Netherlands (Pathologisch-Anatomisch Landelijk Geautomatiseerd Archief) with 100% capture. Twelve cases of HSTCL were identified during this period. The overall incidence of HSTCL in the Dutch population over this period was estimated at 0.06 per million inhabitant-years. All but 2 of the patients were adults at the time of diagnosis (median age, 34.5 years), and most patients died within a year of diagnosis. Three patients had a history of immune-mediated disease, 1 of whom was receiving azathioprine at the time of HSTCL diagnosis. Azathioprine as well as anti-tumor necrosis factor-α agents have been reported as possibly being associated with HSTCL. None of the 12 HSTCL patients had been treated with an anti-tumor necrosis factor-α agent.