Cystic lesion of pancreas Chan Chi King North District Hospital

The tumor, now the size of a small coconut , was a little above and to the left of the umbilicus, feeling like a tense cyst, & pulsating plainly form motion transmitted from the aorta. The dignosis of pancreatic cyst was made.. Ann Surg. 1893 Aug;18(2):227-8

How common? Prevalence 0.21% to 24.3% Ikeda M. et al 1994; Kimura W. et al. 1995 Size and number of pancreatic cysts increase with age Zhang. et al. 2002 ? 80~90% pseudocyst ? 10% cystic neoplasm (1% of primary pancreatic neoplasm)

Cystic lesion of pancreas A broad spectrum of pathological entities Distinguish pancreatic pseudocyst/ non-neoplastic cyst from pancreatic cystic neoplasm Distinguish benign cystic neoplasm from potential malignant cystic neoplasm

Neoplastic lesions Non-neoplastic lesions Serous cystic neoplasm Mucinous cystic neoplasm Intraductal papillary mucinous neoplasm (IPMN) Cystic endocrine neoplasm Solid Pseudopapillary neoplasm Ducal adenocarcinoma with cystic degeneration Acinar cell cystadenocarcinoma Non-neoplastic lesions Pseudocyst Inflammatory pancreatic cyst Simple epithelial cyst VHL Cystic fibrosis

Epidemiology Type Gender Peak age % Serous cystadenoma F>M 70s Brugge WR. et al.NEJM.2004. Type Gender Peak age % Serous cystadenoma F>M 70s 32-39 Mucinous cystic neoplasm 40s 10-45 Intraductal papillary mucinous neoplasm M=F 50s 21-33 Solid pseudopapillary neoplasm 30s <10 Cystic endocrine neoplasm Ductal adenocarcinoma with cystic degeneration M>F <1 Acinar-cell cystadenocarcinoma

Presentation >1/3 of Case Found incidentally during imaging Jaundice.. Abdominal pain.. weight loss.. Anorexia.. History of pancreatitis History of alcohol abuse History of abdominal injury Spinelli KS et al. Ann Surg.2004 Goh BK et al. Am J Surg.2006 Frenandez-del Castilo C et al. Arch Surg.2003 Allen PJ et al. J Gastrointest Surg.2003 >1/3 of Case Symptomatic cysts are associated with higher risk of malignancy ?Cofounding with increased size

Role of CT Characterization of pancreatic cysts May facilitate differentiation between histological variants for larger lesions Remain non-diagnostic for small lesions Firm diagnosis ~ 25 -40%

Cyst with solid component Microcystic Cyst with solid component Unilocular Cyst Marcocystic Dushyant V. Sahani et al. RadioGraphics 2005 Massachusetts General Hospital

Microcystic lesion: serous cystic neoplasm

Mucinous cystic neoplasm Marcocystic lesion Mucinous cystic neoplasm

Cyst with solid component IPMN

Unilocular cyst

Peripheral curvilinear SCN MCN IPMN Location Even Body/tail Head Septae Yes No Locularity Microcystic macrocystic Marcocystic Calcifications Central stellate Peripheral curvilinear None Pancreatic duct PD displaced PD dilated & mucin

Role of MRI Better delineate the architecture of cystic lesion Better delineation of pancreatic duct Not superior to thin cut CT in making diagnosis

Role of PET scan Italian group at Padua Sperti C et al. J Gastrointest surg. 2005 > 90% sensitivity / positive predicting value distinguish malignant from benign Unable to distinguish pre-malignant from benign

morphologyaccuracy ~ 51% Role of EUS morphologyaccuracy ~ 51% Determine type and structure of cystic lesion Facilitate fine needle aspiration Examination of pancreatic ducts and parenchyma

Fine needle aspiraton cystic fluid analysis Cytology Tumor markers CEA, CA19-9, CA 15-3, CA 72-4 Amylase Others

Serous cystic neoplasm Mucinous cystic neoplasm Viscosity Amylase CEA Cytology EUA Serous cystic neoplasm ↓ Glycogen microcysts dense septations honeycomb like. central calcification. Mucinous cystic neoplasm ↑ ↔ Mucin multiple fluid filled cavities thin septations larger than SCN peri. Calcification IPMN Dilated pancreatic duct Connection to duct Multilocular No septations/ calcification Pseudocyst Histiocyte Internal echoes representing debris Unilocular Pancreatitis parenchymal change

Small cystic lesions ( less than 3cm) ~50% pre-malignant potential ~ 13-20% malignancy ( < 3cm) Resect or not to resect? Surveillance? How? How Often? EUS/ CT Individualized decision Retrospective study Selection bias Overestimate the risk

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