Adenocarcinoma arising in an elderly patient's large ileal duplication.

Bowel duplications are rare congenital anomalies commonly found in pediatric patients; few cases may remain undetected until adulthood. Malignant carcinomatous changes are rare complications in intestinal duplications. An 88-year-old female patient was referred to our surgical unit with the diagnosis of a large abdominal mass. An explorative laparotomy was performed, revealing a large (22 × 11 cm) neoplasm strictly connected to the lowest ileal segment and completely filling the pelvis. Definitive histology revealed a moderately differentiated adenocarcinoma developing in a duplication of the terminal ileum. The hypothesis of a gastrointestinal duplication should be evaluated in the differential diagnosis of large, complex, indeterminate masses located in or near the bowel; the possibility of neoplasm within the duplication should be considered.