Polypoid carcinoma of the esophagus.

Polypoid carcinoma of the esophagus is rare and little is known about its clinical and histopathologic features. We reviewed 500 surgical cases of esophageal carcinoma and analyzed 12 polypoid carcinomas. Clinical records were reviewed. Histologic examination was done on an average of 68 sections in each tumor. Immunohistochemical examination for proliferating cell nuclear antigen (PCNA) was done in selected sections. No special findings were seen with respect to age, sex, symptoms, or tumor location. The tumors, however, had several interesting features: 1) the main histologic type was squamous cell carcinoma, but other histologic features such as so-called carcinosarcoma, adenoid cystic carcinoma, and verrucous carcinoma were occasionally seen, 2) bidirectional differentiation to squamous and adenocarcinomatous components was recognized, 3) intraepithelial spreading of the carcinoma was often present, 4) depth of invasion in the wall was often shallow, and 5) the prognosis was relatively good. The PCNA labeling index was well correlated with lymphatic or blood vessel permeation.