Malignant tumors of the small bowel.

The four common types of small bowel malignancies have different clinical presentations, routes of metastatic spread, and prognoses, and may require selective treatment. A review of our experience over a 16-year period revealed 45 cases: 16 adenocarcinomas, 13 carcinoids, nine leiomyosarcomas, five lymphomas, and two fibrosarcomas. Adenocarcinomas tend to occur in the upper part of the small intestine, cause obstruction and occult blood loss, and metastasize to the regional nodes and liver. Carcinoids generally begin in the distal portion of the small bowel, may form rather large metastatic masses and cause obstruction from a metastatic mass or intussusception, and are often multiple. Leiomyosarcomas develop in any part of the bowel, may present a primary mass, gross hemorrhage, or perforation, and have blood-borne metastases. Lymphomas tend to occur in the distal part of the small bowel, with pain or mass formation, and spread via the lymphatics. Critical analysis of the clinical presentation and findings should allow preoperative recognition of the specific pathologic type.