Small cell carcinoma of the colon: barium study and CT findings.

Extrapulmonary small cell carcinoma is a rare neoplasm. It is an aggressive malignant tumour characterized by rapid local progression and early metastasis. We report a case of small cell carcinoma arising in the transverse colon in a 34-year-old man who presented with epigastric pain. On CT, a poorly enhancing bulky mass encircling the transverse colon with extensive regional lymph node metastases was observed. A segmental annular narrowing with thick interhaustral folds of the transverse colon was found by barium enema examination. This is the first report of barium study and CT findings of extrapulmonary small cell carcinoma of the colon.