CD8-positive T-cell lymphoma of the thyroid: A rare case

Malignant lymphoma of the thyroid gland is a rare entity, and the frequency of T-cell lymphoma is even rarer. We present a case of malignant T-cell lymphoma of the thyroid gland that developed in a 73-year-old woman. The patient with a history of Hashimoto's thyroiditis presented to us with the chief complaint of rapidly increasing neck swelling and breathing difficulty. Computed tomography (CT) of the neck showed a large thyroid gland with marked mass effect on the airway and the surrounding structures and was extending into the superior mediastinum. Cytology gave a diagnosis of Bethesda Category VI, positive for malignancy lymphoma. The diagnosis was confirmed on histopathological examination and immunohistochemical examination. Further, positron emission tomography CT scan ruled out any involvement beyond the locoregional region and hence suggested thyroid lymphoma as the primary disease.