Tonsillar metastasis of signet-ring cell adenocarcinoma of the colon

Cases of primary colorectal signet-ring cell carcinoma metastatic to the tonsil are extremely rare. To the best of our knowledge, only 4 such cases have been previously reported in the literature. We report a new case in a 76-year-old white woman. She was treated with chemotherapy, but her disease continued to spread and she was eventually placed on comfort care and palliative radiation therapy. The manner in which tonsillar metastases evolve is still unknown, but some hypotheses have been proposed, and we briefly review these theories.