Cystic tumours of the pancreas.

BACKGROUND: Cystic pancreatic tumours may be misdiagnosed as pseudocysts.
METHODS: From August 1990 to January 1998, 21 patients (16 women) with a median age of 60 years underwent operation for a cystic mass in the pancreas with histological confirmation of neoplasia (six serous cystadenoma (SCA), three mucinous cystic adenoma (MCA), ten mucinous cystadenocarcinoma (MCAC), one ductal adenocarcinoma with cystic degeneration, one cystic islet cell tumour).
RESULTS: While the lesion had been labelled as a pseudocyst in eight patients, only one patient (MCA in the pancreatic head) had had acute pancreatitis previously. In seven patients the computed tomogram (CT) lacked suspicious neoplastic features, while endoscopic retrograde cholangiopancreatography, angiography and percutaneous cyst fluid analysis were unhelpful or misleading in 16 of 18 investigations with respect to differentiating tumour from pseudocyst. Attempted operation for cure was performed in 18 patients despite diagnostic delays of up to 6 years and initial treatment with cystenterostomy in two cases.
CONCLUSION: Retrospective review revealed that all 21 cystic neoplasms could be diagnosed before operation by a history excluding previous pancreatitis (20 of 21 patients) or a CT suspicious for neoplasia (14 of 21). The diagnosis relies more on absence of previous pancreatitis and a suspicious clinician who errs on the side of resecting a pseudocyst rather than watching or draining a cystic neoplasm.