Signet-ring cell carcinoma of the rectum with tonsillar metastasis: a case report.

A 36-year-old man was diagnosed as a case of mucinous adenocarcinoma of the rectum, Dukes' C. Pathologic examination revealed abundant signet-ring cells in the tumor. He did not receive adjuvant radiotherapy or chemotherapy after resection of the tumor. Two years later, a 3 x 5 cm mass over the right palatine tonsil was found with associated right neck lymphadenopathy. Right tonsillectomy was performed. Metastatic mucinous adenocarcinoma of the tonsil with abundant signet-ring cells similar to the primary tumor of the rectum was found. Signet-ring cell carcinoma of the rectum with tonsillar metastasis is extremely rare. No case has been reported in the English literature. To the best of our knowledge, this is the first case of signet-ring cell carcinoma of the rectum with tonsillar metastasis. The relevant literature on metastatic tonsillar tumors is reviewed.