Cystic neoplasms of the pancreas: problems in differential diagnosis.

From 1970 to 1990 we observed 18 patients with histologically proven pancreatic cystic tumors. The average duration of symptoms prior to diagnosis was 14.1 months. A presumptive diagnosis was made preoperatively in nine patients. CT-guided fine needle cytology performed in three cases correctly showed a benign lesion in one patient and malignancy in two patients. Amylase and tumoral marker levels (CEA, CA19-9) were low in cystic fluid of two patients with cystadenomas who underwent preoperative percutaneous aspiration. Intraoperative biopsy of the cystic wall failed to detect epithelial lining in two cases; one patient had internal drainage for cystadenocarcinoma mistaken for pancreatic pseudocyst. Sixteen patients underwent surgery, two of whom died. Of the seven patients with a malignant condition, resection for cure was performed on three. The preoperative diagnosis of these very rare tumors remains difficult. Fine-needle cytology and cystic fluid examination may be a promising technique, but resection of all suspected lesions, whenever possible, is the procedure of choice for diagnosis and treatment.