Anaplastic and sarcomatoid carcinoma of the small intestine: a clinicopathologic study.

Carcinomas involving the jejunum and ileum are rare tumors. During a review of small intestinal neoplasms, six primary carcinomas of jejunum or ileum with an anaplastic and sarcomatoid histology were identified. At presentation, three of the patients had symptoms related to metastatic disease and three had symptoms referable to the local tumor. The tumors were large (greater than 4.5 cm in diameter), usually endophytic masses composed of large cells with eosinophilic cytoplasm, anaplastic nuclei, and prominent nucleoli. In many areas, the cells had a spindled configuration. Mucin positivity was identified in all six cases. Electron microscopic findings in two cases were indicative of epithelial differentiation. The tumors behaved aggressively; all five patients for whom there was clinical follow-up died of metastases within 40 months. The six anaplastic and sarcomatoid carcinomas were compared with 29 typical adenocarcinomas arising in the jejunum or ileum. Only two of the latter group had symptoms referable to distant metastases at presentation. These tumors also tended to be smaller at presentation (11 tumors were less than 4 cm in greatest dimension). Of 25 patients with typical adenocarcinomas who had acceptable follow-up, 18 (72%) died of disease and five (20%) were alive with no evidence of disease after 5 years. We conclude that anaplastic and sarcomatoid carcinoma is a rare variant of small intestinal carcinoma with an aggressive clinical course.