Characterization of malignant pancreatic cystic lesions in the background of chronic pancreatitis.

CONTEXT Cystic lesions of the pancreas in association with chronic pancreatitis are a diagnostic and therapeutic challenge. OBJECTIVE The aim of the study was to study clinical and radiological features that may differentiate between benign and malignant cystic lesions of the pancreas and examine the indications for surgery in these patients. DESIGN Retrospective case note study. PATIENTS Patients with concomitant cystic lesions of the pancreas and chronic pancreatitis stated in radiology reports between 1995 and 2005. RESULTS Thirty-one patients were identified with alcohol-related chronic pancreatitis with a median age of 53 years (range: 27-82 years). Eight patients (26%) had deranged liver function tests and four (13%) presented a raised CA 19.9. Radiological features of cystic lesions of the pancreas included median cyst size of 3 cm (range: 0.8-10 cm), solitary cyst in 28 patients (90%) and multi-loculated in 3 patients (10%). Dilatation of the main pancreatic duct was seen in seven cases (23%). Overall, 12 patients (39%) underwent surgery, 13 patients (42%) were managed with radiological follow-up, five patients (16%) were managed conservatively and one patient (3%) was treated with chemotherapy for advanced malignancy. Overall, three cases (10%) of this series had malignant cystic lesions of the pancreas. Malignant cystic lesions of the pancreas are associated with deranged liver function tests, elevated CA 19.9, and are larger solitary cysts on imaging. CONCLUSION The differentiation between benign and malignant cystic lesions of the pancreas remains a diagnostic challenge, although malignant cysts tend to be solitary and larger. The high prevalence of malignancy merits an aggressive approach to follow-up and early surgical intervention.