A giant abdominal cyst with raised levels of carbohydrate antigen 19-9

A 53-year-old woman was admitted with upper abdominal discomfort. Clinical examination revealed a mass of the upper left quadrant. Computed tomography disclosed a giant cystic lesion of 19 x 16 cm compressing the body and tail of the pancreas as well as the left kidney. Endoscopic ultrasound showed an anechoic lesion with multiple septa. Diagnostic fine needle aspiration was performed. Intracystic carcinoembryonic antigen and lipase values were normal. However, carbohydrate antigen 19-9 level was elevated (3433 UI/ml) and cytologic examination was compatible with a pancreatic serous cystadenoma. Prompted by the symptoms and the lack of a definite diagnosis, the patient underwent cystectomy. Surprisingly the histological diagnosis was that of a benign renal cyst. To date, only one case of a giant renal cyst has been reported with high levels of CA 19-9. With this case report we would like to demonstrate that giant renal cysts may present high levels of CA 19-9 and mimic the endoscopic ultrasound aspect and cytologic features of pancreatic cysts.