True about small bowel tumour -

• MC malignant neoplasms of the small bowel: Carcinoid tumors >adenocarcinomas >malignant GISTs >lymphomas. • Adenocarcinomas are more numerous in the proximal small bowel, whereas the other malignant lesions are more common in the distal intestine (ileum). Clinical Features • In contrast to benign lesions, malignant neoplasms almost always produce symptoms • MC symptom: Abdominal pain >weight loss • Obstruction develops in 15-35% of patients and, in contrast to the intussusception produced by benign lesions, is usually the result of tumor infiltration and adhesions. • Diarrhea with tenesmus and passage of large amounts of mucus may occur. • Adenocarcinomas may produce the typical constricting apple-core lesions similar to those observed in the colon. • Gastrointestinal bleeding is more common with leiomyosarcomas. • A palpable mass may be felt in 10-20% of patients, and perforations develop in about 10%, usually secondary to lymphomas and sarcomas. Diagnosis • Barium meal follow through (BMFT): Accurate diagnosis in 50–70% of patients with malignant neoplasms of the small intestine • Enteroclysis (small bowel enema): Diagnostic accuracy of about 90% Treatment • Wide resection including regional lymph nodes. • Often, surgical resection for cure is not possible. Therefore, palliative resection should be performed to prevent further complications of bleeding, obstruction, and perforation. • Adjuvant radiation and chemotherapy have little role in the treatment of patients with adenocarcinomas of the small bowel. Prognosis • Only half of the patients operated on for malignant tumors of the small intestine have lesions amenable to curative resection. • One third have a distant metastasis at the time of initial surgery • Overall 5-year survival rate after surgical treatment of malignant tumors is only 25% • Adenocarcinoma has the poorest prognosis, with an overall survival rate of 15-20%. • Obstruction in CA small bowel develops in 15-35% of patients, due to tumor infiltration and adhesions. • Obstruction in benign lesions is due to intussusceptions.