Small bowel malignancy.

Small bowel malignant tumors account for little more than 1% of all gastrointestinal (GI) malignancies. In the period 1972–1982, the annual incidence rate of these tumors in the United States was 0.96 per 100,000 [1]. The incidences of the most common varieties of small bowel malignancies are reported in Table 1. As in many other malignancies, the incidences of carcinoma, carcinoid, and lymphoma increase with age, whereas that of sarcoma reaches a plateau after the sixth decade. The majority of small bowel malignancies becomes symptomatic after a silent phase of variable length [2]. The most frequent symptoms are occult GI bleeding, abdominal pain, weight loss, and diarrhea (especially in lymphomas), whereas frank bleeding, intussusception, and perforation are less common. Flushing occurs in a minority of metastatic carcinoid tumors. A palpable abdominal mass is encountered in up to 40% of cases and is usually a late finding. Because of the poor accessibility of the small bowel to conventional diagnostic modalities as well as the late onset of symptoms, small bowel malignancies often represent a clinical challenge.