T-cell Lymphoma of Thyroid Gland with Lennert Type of Morphology: A Case Report and Review of the Literature.

The rare entity of primary T-cell lymphoma of thyroid gland may pose great diagnostic and therapeutic challenges to the pathologist and clinician. There are very few case and short series reports of these tumors describing their varied clinicopathologic features in English literature. We report a case of mature T-cell lymphoma of thyroid in a 26 year old male, with unique pseudogranulomatous and lymphohistiocytic Lennert type of morphology, on a background of autoimmune thyroiditis. This man, diagnosed with Hashimoto's thyroiditis for the previous 2 years, underwent thyroidectomy for sudden onset of pressure symptoms. The diagnosis of T-cell lymphoma was made on the thyroid tissue based on histopathologic and immunophenotypic findings, in concert with the results of T-cell receptor gene rearrangement studies by polymerase chain reaction. Later, after about 3 months, similar findings were confirmed in an excision biopsy from a left cervical lymph node in the patient. The patient has been started on chemotherapy with gemcitabine, dexamethasone, and cisplatin along with involved field radiotherapy; however, he has shown a rapid upstaging of disease from stage IE to IIIE in a short period of 3 months with relatively well preserved clinical parameters until the latest follow up.