Malignant tumors of the small intestine.

The four main histologic categories of malignant small intestine tumors are (1) adenocarcinoma, (2) sarcoma, (3) carcinoid, and (4) lymphoma. Signs and symptoms may be chronic or acute and include bleeding, obstruction, pain, and weight loss. When chronic, the symptoms are so vague that early diagnosis is difficult. Often the diagnosis is made only at the time of surgery. Treatment is segmental resection of intestine with adequate margin of the tumor and resection of the regional lymph nodes. Prognosis is evaluated by tumor extension through the bowel wall and lymph node metastasis. The 5-year survival rates are low except for carcinoid and lymphomatous lesions.