ABSTRACT
We report a rare case of co-occurrence of papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC) and primary thyroid lymphoma. A 55-year-old woman presented with a large mass in left lobe of thyroid, biopsy confirmed diffuse large B-cell lymphoma. After 4 cycles of rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisolone chemotherapy, positron emission tomography scan revealed markedly decreased in size, but still present. Repeated ultrasonography-guided gun biopsies of 2 lesions indicated Hurthle cell neoplasm. After total thyroidectomy and bilateral central lymph node dissection, residual hypermetabolic lesion of left lobe was determined to be FTC and right lower lesion to be nodular hyperplasia. Besides, a PTC was incidentally detected in left lobe. If there are multiple nodular lesions at diagnosis or there is insufficient response after 1st line chemotherapy for primary thyroid lymphoma, each lesion should be biopsied to confirm its pathological type.