Obstipation as a paraneoplastic presentation of small cell lung cancer: case report and literature review.

Paraneoplastic symptoms caused by abnormal gastrointestinal motility may be the initial manifestation of small cell lung cancer (SCLC). We report a case of a 63-year-old woman who presented with progressive constipation culminating in obstipation, and associated symptoms of more widespread dysmotility. A paraneoplastic syndrome was suspected. The only abnormality on chest computed tomography was a minimally enlarged paratracheal lymph node. Positron emission tomography demonstrated increased activity in the lymph node. The antinuclear neuronal antibody titer was elevated. Bronchoscopy with transtracheal biopsy confirmed the diagnosis of SCLC. One year after diagnosis, the patient had progressive symptoms of intestinal obstruction, and ultimately feculent vomiting. On abdominal radiography, colonic sitz markers ingested a year earlier were in virtually the same positions as after ingestion. Palliative colectomy with ileostomy was performed. The myenteric plexus in the terminal ileum and colon showed infiltration by a mixture of B-cell and T-cell lymphocytes and plasma cells, and no gross neuronal abnormalities. We review the clinical and pathologic features, clinical course, and management of paraneoplastic pseudoobstruction.