A case of resection of lung squamous cell carcinoma complicated by intratumoral thyroid carcinoma micrometastasis

Abstract

The patient was a 72-year-old woman who was diagnosed with papillary thyroid carcinoma by another physician and underwent a total thyroidectomy and cervical lymph node dissection. She visited a local physician presenting a cough. Chest x-ray conducted by the physician indicated a nodular shadow, and therefore was referred to our hospital. Surgery was performed because of a growing tendency of the shadow. The patient was diagnosed with lung cancer based on intraoperative rapid diagnosis, and underwent a right lower lobectomy and lymph node dissection (ND2a). Postoperative pathology showed it to be a well-differentiated, distinctly cornified squamous cell carcinoma with four intratumoral micropapillary carcinomas. Similar papillary carcinoma microlesions were scattered in the normal lung tissue apart from the main tumor. Immunostaining found that squamous cell carcinoma and papillary carcinoma were positive for cytokeratin staining, and that only papillary cell carcinoma was positive for thyroglobulin staining. According to this result, they were diagnosed as primary lung squamous cell carcinoma with thyroid papillary carcinoma metastasis complication. As this is a rare condition, we report it with bibliographic consideration.