SEROUS CYSTADENOMA OF PANCREAS: WHY THERE IS LOW ACCURACY IN IMAGING EXAMS?

Many patients with serous cystadenoma of the pancreas (SCP) underwent surgery due to diagnostic doubt. The aim of this study was to analyze the causes of low accuracy in diagnosing SCP.

This is a retrospective study of patients with SCP from a database of two hepatopancreatic biliary surgery outpatient clinics between 2006 and 2020. Patients with typical SCP lesions in imaging exams (e.g., tomography, magnetic resonance imaging [MRI], and endoscopic ultrasound [EUS]) and patients whose pathological testing confirmed this diagnosis were included.

A total of 27 patients were included in this study. Most patients were women (85.18%), and the mean age was 63.4 years. Only one patient had typical pancreatitis symptoms. MRI was the most performed method (62.9%). The lesion was single in 88.9%, and the average size was 4 cm. The typical microcystic aspect was found in 66.6%. EUS was performed in 29.6% of cases. The mean carcinoembryonic antigen value in patients undergoing cyst puncture was 198.25 ng/mL. Surgical treatment was performed in 10 cases (37%). The cause of surgery in seven of these cases was due to a suspicion of mucinous cystadenoma based on an identification of atypical lesions (unilocular with or without septa and macrocystic) in imaging exams. A suspicion of intraductal papillary mucinous neoplasm with "worrying factors" was the indication for surgery in two cases. The last case underwent surgical treatment for a solid-looking lesion which was suspected of cancer. The complication rate ≥Clavien-Dindo 2 was 30%, and the clinically relevant pancreatic fistula rate (B and C) was 30%. Mortality was nil.

The atypical morphological presentation of SCP, particularly unilocular and macrocystic lesions, is the main indication for surgery. Only the implementation of new, efficient, and reproducible diagnostic methods can reduce the number of unnecessary surgeries among these patients.