Esophageal mucoepidermoid carcinoma containing signet-ring cells: three case reports and a literature review.

We report 3 cases of esophageal signet-ring cell carcinoma which were found in a set of 505 resected esophageal tumors. The incidence of esophageal signet-ring cell carcinoma was 0.6%. All of the signet-ring cell carcinomas were histologically mixed with squamous cell carcinoma (mucoepidermoid carcinoma). The signet-ring cells had intracellular mucin, which was positive for both periodic acid-Schiff (PAS) and alcian blue at pH 2.5. At the time of presentation, extensive extraesophageal tumor spread and local extension were found in all cases. All of the patients died within 2 years after the esophagectomy irrespective of whether they received chemotherapy or radiotherapy. Our results, and those previously reported, suggest that most esophageal carcinomas containing signet-ring cell carcinoma are aggressive neoplasms associated with a poor prognosis after esophagectomy.