Macrocystic form of serous pancreatic cystadenoma.

OBJECTIVES: Macrocystic serous cystadenoma of the pancreas are benign lesions with sometimes difficult diagnostic issues. We aimed to describe clinicopathological and imaging features with cyst fluid analysis in a series of patients undergoing surgery for macrocystic serous cystadenoma.

METHODS: Eight patients underwent pancreatic resection for a macrocystic lesion of the pancreas diagnosed on ultrasonography or CT. Endoscopic ultrasonography and preoperative fine-needle aspiration were performed in seven patients. Immunohistochemical analysis of the surgical specimen with antibodies to carcinoembryonic-antigen (CEA), carbohydrate antigen (CA) 19-9, estrogen receptor, and progesterone receptor antibodies was performed in all cases.

RESULTS: Patients included seven women and one man, with a mean age of 48 yr. Lesions were incidentally discovered on ultrasonography in six patients and had a mean size of 3 cm (range, 1.5-5 cm). Endoscopic ultrasonography revealed millimetric cysts in three cases. In the seven aspirated cysts, cytological analysis was non-contributive, but biochemical analysis showed low content of CEA (< 5 ng/ml) and CA72.4 (< 40U/ml) in all but two. At histology, cysts were lined by clear cuboidal cells. They focally expressed CA19-9 but were negative for anti-CEA, antiestrogen receptor, and antiprogesterone receptor antibodies. Microscopic cysts in the wall of the lesions were demonstrated in five cases.

CONCLUSIONS: Macrocystic serous cystadenoma is a particular variant of pancreatic serous cystadenoma. Endoscopic ultrasonography may be useful in detecting peripherally located millimetric cysts in unilocular lesions, and measurement of enzymes and tumor markers in cyst fluid may also contribute to the diagnosis showing low concentrations.