Anaplastic and sarcomatoid carcinoma of the small intestine: an unusual tumor.

Primary malignant tumors of the small intestine are rare, and sarcomatoid carcinomas have rarely been reported at this site. Anaplastic and sarcomatoid carcinomas are well described in the upper aerodigestive tract, particularly in the esophagus and the larynx. The authors report a case of anaplastic and sarcomatoid carcinoma of the ileum presenting as gastrointestinal bleeding. Their patient and the literature suggest that these tumors are much more aggressive than other small intestinal tumors. The importance of a systematic diagnostic approach in diagnosing these tumors is also discussed.