<prompt> True about small bowel tumour -Commonly located in duodenumLymphoma is commonAdenocarcinoma has good prognosisPalliative surgeries are done even in presence of metastasis  <response>: 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 5070 of patients with malignant neoplasms of the small intestine Enteroclysis small bowel enema: Diagnostic accuracy of about 90Treatment 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. 