Serous cystadenoma of the pancreas

Clinical History

A 35-year-old woman with abdominal discomfort and a palpable mass in the upper abdomen. Ultrasound and CT of the abdomen showed a cystic lesion with central calcification, adjacent to the head of the pancreas.

Imaging Findings

The patient was admitted to our hospital because of vague abdominal discomfort of two month's duration. She did not report fever, anorexia or weight loss and her history was unremarkable. On physical examination a smooth, non-tender mass was palpable in the upper abdomen. Laboratory values were within normal ranges. An abdominal ultrasound showed a round, well circumscribed, cystic lesion, in the upper abdomen. The lesion was 8X10 cm and consisted of a main large cyst with several small cysts in the periphery. An axial CT scan of the abdomen demonstrated well defined cysts, adjacent to the pancreatic head (Figure 1). After intravenous contrast enhancement numerous calcifications in the center of the largest cyst were seen. The cysts were separated by well enhanced septations, with slight irregularities on their inner surface (Figure 1). A well-demarcated, homogenous, hypodense area was present in the liver (Figure 2). Exploratory surgery showed a cystic lesion originating from the head of the pancreas. The cysts were resected along with surrounding pancreatic tissues, and biopsy of the hepatic lesion was performed.

Discussion

The resected tissue consisted of a main large cyst and several small cysts, containing serous fluid. Histology showed that the lesion was oligocystic serous cystadenoma of the pancreas and the concurrent hepatic lesion was a hemangioma. No evidence of malignancy was found. Cystic lesions of the pancreas are usually complication of pancreatitis. Cystic neoplasms are rare and are divided in serous and mucinous cystadenomas (1). A serous cystadenoma consists of small cysts lined with epithelial cells containing glycogen but no mucin (2). Larger cysts are usually found in the periphery of the tumor. Calcification occurs in the central area in approximately half of the cases (3). Serous cystadenomas are usually bening. Macrocystic (unilocular, oligocystic) serous cystadenoma is a variant of the typical serous cystadenoma, and can be easily confused with pseudocyst and mucinous cystadenocarcinoma. In our case, the lesions were initially misdiagnosed as pancreatic cystadenocarcinoma with hepatic metastases. The difficulty in differentiating between pancreatic serous cystadenomas and mucinous cystadenocarcinomas dictates that surgical exploration should be always performed. The patient was free of disease one year after the operation.

Differential Diagnosis List

Final Diagnosis

Macrocystic serous cystadenoma of the pancreas

URL:	https://www.eurorad.org/case/1129
DOI:	10.1594/EURORAD/CASE.1129
ISSN:	1563-4086