Isolated metastasis of lung cancer to the thyroid gland.

A 67-year-old man with lung cancer developed an isolated metastasis to the thyroid gland. The patient had undergone a right upper lobectomy, followed by chemotherapy consisting of cisplatin and etoposide based on post-surgical diagnosis of small cell lung cancer. Four years later, he had an isolated metastasis to the thyroid gland. The patient underwent a metastasectomy and adjuvant chemotherapy including cisplatin and irinotecan. The cancer cells in resected thyroid tumor had large nuclei and cytoplasm, and expressed the neuroendocrine markers, CD56 and chromogranin A. Retrospectively, the primary lung cancer consisted of both small cell and large cell cancer, and the latter was consistent with the pathological finding of the thyroid tumor. This is the first report to document an isolated recurrence of the lung cancer to the thyroid.