Carbohydrate antigen 19-9-producing splenic cyst: a case report.

We describe the case of a 40s woman with a carbohydrate antigen (CA)19-9-producing splenic cyst. The lesion was detected incidentally at the splenic hilum, and resected after 5 years of follow-up. Size of the lesion was enlarged from 1.6 cm to 5.3 cm, and serum CA19-9 was elevated from the normal range to 1766 U/ml. Microscopically, CA19-9-producing splenic cyst was diagnosed. It was mimicked pancreatic malignancy due to its location at the splenic hilum. Benign lesions with elevated serum CA19-9 also to be differential diagnosis.