Noriko Okuno, Shintaro Terahata, Shun Sugiguchi and Sadaya Matano
Primary thyroid T-cell lymphoma is rare, with only 19 cases reported previously. T-cell prolymphocytic leukemia/ lymphoma (T-PLL) is a rare entity among T-cell lymphomas. T-PLL patients present with hepatosplenomegaly, lymphadenopathy, skin infiltration and a high leukocyte count, sometimes with anaemia and thrombocytopenia, but thyroid infiltration has been reported in only one other case. Here, we report an extremely rare case of T-PLL with foci seen in the thyroid gland and bone-marrow. Confirming the primary lesion was difficult, but the clinical and histopathological features suggest the thyroid gland as the primary lesion.