Collision tumor in the ileum: a rare combination of an adenocarcinoma and small cell neuroendocrine tumor.

We present a case of a rare small bowel tumor. A 73-year-old female patient presented at our department with vague abdominal pain. Ultrasound examination discovered an inhomogeneous vascularised mass originating from a small bowel loop, mesenteric enlarged lymph nodes and a nodule in the liver. Multislice Computed Tomography of the abdomen confirmed the ultrasonographic findings and found omental implants together with a left-sided ovarian mass. Surgery was performed. Pathology revealed a rare ileal collision tumor consisting of an adenocarcinoma and a small cell neuroendocrine tumor with peritoneal metastasis of neuroendocrine origin and coincidental benign lesions on both ovaries.