Pituitary gland involvement by a gamma delta hepatosplenic lymphoma, a mimicker of pituitary adenoma: report of a rare case

The authors report an unusual case of hepatosplenic T-cell lymphoma in a 41-year-old male patient. He presented initially with low grade fever, hepato-splenomegaly and pancytopenia. Splenectomy was done which showed infiltration of red pulp by monomorphic lymphocytes. Liver was also infiltrated with similar cells. A provisional diagnosis of hairy cell leukemia was made. Subsequently, after 6 months he was found to have a sellar mass, which on microscopy revealed lymphoma cells. These cells were positive for leukocyte common antigen and T-cell markers. Finally, based on overall clinical, histomorphological and immunophenotypic features, a diagnosis of hepatosplenic T-cell lymphoma, possibly gamma delta type, involving pituitary gland was established. On follow up, this patient showed evidence of bone marrow involvement and died after 1.5-year of diagnosis. This case highlights the involvement of rare site by a rare lymphoma and should be kept in mind in the differential diagnoses of pituitary tumors.