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, hepatosplenomegaly 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.