Primary thyroid diffuse large B-cell lymphoma coexistent with papillary thyroid carcinoma: A case report.

BACKGROUND Primary thyroid lymphoma (PTL) is uncommon, accounting for 2% to 5% of all thyroid malignancies. Papillary thyroid carcinoma (PTC) is the most frequent thyroid cancer. The coexistence of PTL and PTC is very rare, and the preoperative diagnosis is rather difficult. METHODS A 41-year-old male patient complaining of fast painless thyroid enlargement for 2 months and a cervical mass for half a month was presented. Imaging demonstrated an enlarged thyroid and a mass in the thyroid. RESULTS Surgery was conducted, and the final diagnosis of coexistence of PTL and PTC was confirmed by histopathological and immunohistochemical examination. The patient was then treated with cyclophosphamide, hydroxy doxorubicin, oncovin, prednisone (CHOP) chemotherapy and radiotherapy. After 2 months of follow-up, no recurrence or metastasis was noted. CONCLUSION This rare case highlights the importance for physicians to keep PTL in mind for differential diagnosis in patients with sudden thyroid enlargement and who have clinical history of Hashimoto thyroiditis.