A case of cervical thymic carcinoma preoperatively diagnosed as thyroid carcinoma

Abstract

We report a case of cervical thymic carcinoma extended to the superior mediastinum which was preoperatively diagnosed as thyroid carcinoma. A 61-year-old man presented with an anterior neck mass which he had suffered for 6 years. Magnetic resonance imaging revealed that the mass extended from the thyroid gland to the superior mediastinum. Cytological diagnosis suggested the mass was possibly a papillary carcinoma. Based on the preoperative diagnosis, total thyroidectomy was performed. The histological assessment was carcinoma showing thymus-like differentiation (CASTLE) or thymic carcinoma. Because the tumor was clearly separated from the thyroid gland, we finally made a diagnosis of thymic carcinoma. Radiotherapy was not administered because the mass was completely resected. Fifteen months after the surgery, there was no evidence of recurrence.