Extrapulmonary Small Cell Carcinoma: An Unfortunate Case of Metastatic Disease

Abstract

Abstract A 48- year-old man presented with weight loss and 3 weeks of right sided lower abdominal pain. Liver ultrasound and contrast-enhanced computed tomographic scan of the chest, abdomen, and pelvis revealed a 6.8 x 4.3 cm mass like thickening of ascending colon, with numerous hepatic lesions, enlarged mesenteric lymph nodes, peritoneal nodularity and multiple small (2-4 mm) pulmonary nodules concerning for widely metastatic disease (Figure A). A colonoscopy revealed an ulcerated right colon mass obliterating the lumen (Figure B). Histologic examination showed highly proliferative round cells with a high nuclear to cytoplasmic ratio with adjacent high grade adenomatous change (Figure C). Immunohistochemical stain was positive for synaptophysin (Figure D). Histologic examination of a liver lesion revealed similar histology. Findings were consistent with high-grade metastatic extrapulmonary small cell carcinoma (EPSCC), a rare neuroendocrine carcinoma. Data from the National Cancer Institute's Surveillance, Epidemiology and End Results program from 1992 to 2010 reflects the rarity of EPSCC of the colon and rectum with an incidence rate of