Morphological Classification of Serous Cystic Tumor (SCT) of Pancreas and its Clinical Significance

Kim, Young Hun; Kim, Sun Whe; Jang, Jin Young; Yoon, Yoo Seok; Choi, Min Gew; Han, Sung Sik; Kim, Woo Ho; Lee, Kuhn Uk; Park, Yong Hyun

Abstract

PURPOSE
Honeycomb microcystic tumor is typical for SCT, but various SCTs including oligocystic tumor have been frequently reported. We classified SCT morphologically according to the gross and radiologic feature, and we analyzed the clinical features for the subtypes of SCT. We also suggest the guidelines for the differential diagnosis from mucinous cystic tumors (MCT) and the appropriate management. METHODS: This study enrolled 31 patients with SCT and 37 patients with MCT of the pancreas that were treated from Jan. 1992 to Oct. 2003 at Seoul National University Hospital. When the SCTs were classified according to cyst size and multiplicity, 13 were microcystic tumor and 18 were macrocystic tumor. We then compared microcystic SCT with mcrocystic SCT and we also compared macrocystic SCT with MCT. RESULTS: The mean age of patients with SCT was 50 (range: 31~77) and the male : female ratio was 1 : 3. The head : tail ratio was 14 : 18. There was no malignant SCT and no tumor recurrence. There was no difference between the microcystic and macrocystic type tumors according to the patients' age, gender and symptoms, and for the tumors' location and size. But preoperative misdiagnosis occurred 15.4% of the time for the microcystic type and 61.1% of the time for the macrocystic type (p=0.01). When we compared macrocystic SCT with MCT, there was no difference in the patients' age and symptoms, or for the tumors' size and the CA19-9 level in the serum. However, a difference was found for the tumors' location and the patients' gender ratio. There was a difference for the tumor location (p=0.043) and the patients' gender ratio (p=0.082). CONCLUSION: According to morphological features, we could classify SCT into two types (microcystic vs. macrocystic). Microcystic SCT can be accurately diagnosed at the preoperative stage, so conservative treatment and observation is possible. Macrocystic SCT is difficult to differentiate from the other pancreatic cystic tumors with malignant potential, so resection is recommended.