2021 Volume 60 Issue 6 Pages 324-330
Background : Intrathyroid thymic carcinoma (ITTC) is a rare tumor. We report a case of ITTC accompanied by associated with papillary carcinoma (PC).
Case : The patient, a man in his 60s, presented with the chief complaint of dysphagia to a neighborhood hospital, where examination revealed two nodules in the left lobe of the thyroid gland. He was referred to our hospital for surgical treatment and we performed total thyroidectomy. Intraoperative frozen section diagnosis and imprint cytology were performed for the mass in the lower pole of the left lobe of the thyroid gland.
Cytologically, there were large aggregates of atypical cells with prominent nucleoli in an inflammatory background. Immunocytochemically, the tumor cells showed positive staining for CK5/6, CD5, c-kit, and p63, but negative staining for thyroglobulin, TTF-1, PAX8, and calcitonin. Histologically, the mass in the lower pole of the left lobe of the thyroid gland consisted of large polygonal cells in an insular growth pattern, showing occasional squamous differentiation, accompanied by inflammatory cell infiltration of the tumor nests. Because the immunohistochemical findings were almost the same as those of the imprint cytology, the lesion was diagnosed as an ITTC. The mass in the upper pole of the left lobe of the thyroid gland was a PC.
Conclusion : Cases of ITTC and PC occurring in the two lobes of the thyroid gland have been reported. However, there are no previous reports of the two tumors occurring in the same lobe of the thyroid gland.
