[1639] Clinicopathologic Analysis of Cystic Ductal Adenocarcinoma of Pancreas – Neglected Variant of Pancreatic Ductal Adenocarcinoma

HJ Park, JY Kim, KT Jang. Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

Background: Pancreatic ductal adenocarcinoma usually present as a solid tumor and it is rare that pancreatic ductal adenocarcinoma presents as predominantly cystic tumor. Although there are some case reports of cystic ductal adenocarcinoma (CDA) of pancreas, little is known about the clinicopathologic characteristics of CDA.
Design: We reviewed surgically resected pancreatic ductal adenocarcinoma from 1996 to 2009. We found 8 cases of CDA, presenting as predominantly cystic tumor in preoperative radiological evaluation and pathologic gross examination. The main differential diagnoses of CDA are mucinous cystadenocarcinoma, cancer associated pseudocyst, and retention cyst. Mucinous cystadenocarcinoma was differentiated by absence of ovarian stoma. Retention cyst and pseudocyst were ruled out by identification of cyst lined mucosal carcinoma in CDA.
Results: Of 295 pancreatic ductal carcinomas, 8 (2.7%) showed predominantly cystic tumor in preoperative radiological evaluation and pathologic gross examination. Preoperative impressions were mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, or cancer associated pseudocyst. Six patients were female and 3 were male. Mean age was 68 yrs (39-78). Median size of CDA was 9 cm (3.5-15). The locations of CDA were 6 tail, 2 head, and 1 body, respectively. We found 3 different mechanism of cystic change of CDA; central necrosis, cystic dilatation, and pseudocyst-like change. In the mean follow-up period of 12 months (8-20), 7 patients showed tumor recurrence, including peritoneal carcinomatosis and distant metastasis to liver and brain. All 7 patients showed an increased serum CA 19-9 at recurrence and metastasis. Five patients died of disease.
Conclusions: CDA could be made by either each mechanism of central necrosis, cystic dilatation, pseudocyst-like change or combination of mechanisms. Although it is rare, pancreatic ductal adenocarcinoma may present as predominantly cystic tumor. CDA should be differentiated with mucinous cystadenocarcinoma by careful identification of ovarian stroma. Also CDA could be differentiated with cancer related pseudocyst or retention cyst by careful gross and microscopic examination of cyst lining epithelium. Because CDA is not well known to radiologist, clinicians and pathologist. CDA may be overlooked in preoperative radiologic evaluation and pathologic diagnosis. Pathologist should avoid an erroneous diagnosis of CDA as mucinous cystadenocarcinoma or cancer associated pseudocyst or retention cyst.
Category: Liver & Pancreas

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 203, Tuesday Afternoon

 

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