2 PATIENTS WITH METASTASIS OF CANCER TO OTHER NEOPLASM - A THYROID-CARCINOMA METASTATIC TO A LUNG-CARCINOMA AND A GASTRIC-CARCINOMA METASTATIC TO A THYROID ADENOMA

Two patients with rare cancer-to-neoplasm metastasis are presented. On e patient was a 69-year-old woman who had undergone gastrectomy for ga stric cancer 10 months previously and died of generalized metastases. An autopsy revealed generalized metastases of the gastric carcinoma, t ogether with a cystic, hemorrhagic thyroid tumor measuring 2.0 cm in d iameter. Histologically, the thyroid tumor was an oxyphilic adenoma wi th multiple metastatic foci of gastric adenocarcinoma. Because no meta stasis was found in the background thyroid tissue, this metastasis mig ht have developed specifically and not by chance, most likely due to t he rich vascularity and good circulation of the thyroid adenoma. The o ther patient was an 82-year-old man who had undergone total thyroidect omy for thyroid cancer 6 years previously. An abnormal lung shadow was found on a chest radiograph during postoperative follow-up. Transbron chial biopsy of the lung tumor revealed a squamous-cell carcinoma. The resected lung tumor measured 2.7 cm in diameter, with small foci of m etastatic papillary carcinoma of the thyroid gland and multiple small metastases in the background lung tissue, indicating that the metastas es to lung cancer had occurred by chance. Metastasis of cancer to othe r neoplasms is discussed, and a review of the literature is presented.