Imaging of Pancreatic Cystic Lesions

1. Imaging of Pancreatic Cystic Lesions John Murray MD, Bruce Stewart MD & Alvin Yamamoto MD NSMC Radiology Department Meeting February 4, 2009

2. Outline • BS: Overview & Approach to Cystic Pancreatic Lesions • JM: Intraductal Papillary Mucinous Neoplasms (IPMN) • AY: NSMC Cases

3. Introduction • Increasingly incidentally detected • More than 1/3 asymptomatic • Imaging important for determining prognosis and management • CT>MR generally preferred for characterization except for IPMN • Simple classification for approach to DDx • DDx discussed here account for 90% lesions • Role of Endoscopic US

4. Cystic Pancreatic lesions: A Simple Imaging-based Classification System for Guiding ManagementSahani DV, Kadavigere R, Saokar A, Fernandez-del Castillo C, Brugge WR, Hahn PF.Radiographics 2005 Nov-Dec;25(6):1471-84.

5. Classification of Cystic Pancreatic Lesions • Pseudocyst • Common cystic pancreatic neoplasms • Serous cystadenoma • Mucinous cystic neoplasm • IPMN • Rare cystic pancreatic neoplasms • Solid pseudopapillary tumor • Acinar cell cystadenocarcinoma • Lymphangioma • Hemangioma • Paraganglioma

6. Classification of Cystic Pancreatic Lesions (cont) • Solid pancreatic lesions with cystic degeneration • Pancreatic adenocarcinoma • Cystic islet cell tumor (insulinoma, glucagonoma, gastrinoma) • Metastasis • Cystic teratoma • Sarcoma • True epithelial cysts* *Associated with von Hippel–Lindau disease, autosomal -dominant polycystic kidney disease, and cystic fibrosis)

7. Four Morphologic Types of Cystic Lesions of the Pancreas

8. Unilocular Cyst • Pseudocyst • IPMN occasionally • Unilocular serous cystadenoma • Lymphoepithelial cyst • Multiple • von Hippel-Lindau • Pseudocysts

9. Pseudocyst • Generally symptomatic (i.e. pain) • If asymptomatic, think about another Dx • History of acute or chronic pancreatitis • Almost always pseudocyst with this history • Look for associated findings • Pancreatic inflammation, parenchymal calcifications, atrophy, typical intraductal calcifications • Can communicate with pancreatic duct • Wide neck vs. narrow neck for IPMN • Wall can calcify • No mural nodules

10. Pseudocyst

11. Pseudocyst in a patient with a recent history of pancreatitis

12. Side-branch IPMN manifesting as a unilocular cyst

13. Multiple unilocular cysts in a patient withvon Hippel–Lindau disease

14. Microcystic Lesions • Serous cystadenoma • Only lesion included in this category • Benign tumor • “Grandmother Lesion” • May grow up to approx 4 mm/year • 70% cases demonstrate: • Polycystic/microcystic pattern • Collection of cysts (>6) • Range: few mm – 2 cm • External lobulations • Enhancing septa, walls • 30% demonstrate fibrous central scar +/- stellate calcifcation • Other variants (macrocystic + oligocystic)

15. Serous cystadenoma in 2 patients

16. Serous cystadenoma(macrocystic variant)

17. Macrocystic Lesions • Mucinous cystic neoplasms • Intraductal Papillary Mucinous Neoplasm (IPMN)

18. Mucinous cystic neoplasms • Mucinous cystadenomas & cystadenocarcinomas • Multilocular with complex internal architecture • May contain internal hemorrhage or debris • Peripheral eggshell Ca++ predictive of malignancy • Body & tail of pancreas • Asymptomatic in 75% cases • If symptoms, usually due to mass effect • “Mother Lesion” • High potential for malignancy • Surgical resection yields good prognosis

19. Mucinous cystadenoma manifesting as a multiseptated cyst

20. Mucinous cystadenocarcinoma

21. Mucinous cystic tumor

22. Mucinous cystadenoma

23. IPMN Pathology: Borderline IPMN w/o in situ or invasive carcinoma Radiographics 2005; 25:1451-1470

24. Endoscopic US • Can provide detailed morphologic evaluation of cystic lesions • For detecting malignant tumors: • Sensitivity: 40% • Specificity: 100% • Accuracy: 50% • Advantage of aspiration of contents, sampling of cyst wall, septa or mural nodule • Less potential for tumor seeding than percutaneous sampling • Highly viscous contents (mucin) consistent with mucinous neoplasm • Tumor markers, cytologic analysis, biochemical markers, fluid amylase • At NSMC, performed by Drs. Jeff Oringer & Khoa Do

25. Cysts with a solid component • Unilocular or multilocular • True cystic tumors or solid pancreatic neoplasms with cystic component/degeneration • Wide DDx • Mucinous cystic neoplasms • IPMNs • Islet cell tumor • Solid pseudopapillary tumor (SPEN) • Adenocarcinoma • Metastasis • All malignant or have a high malignant potential • Surgical management

26. Islet cell tumor manifesting as a cyst with a solid component

27. Solid pseudopapillary tumor manifesting as a cyst with a solid component

28. Metastases manifesting as cysts with solid components Pancreatic Adenocarcinoma Malignant IPMN

29. Management

30. Follow-up • No consensus • 6 month intervals for 1st year • Annual imaging for 3 years

31. Pearls • Age & Gender • “Daughter Lesion”: SPEN • “Mother Lesion”: Mucinous cystic • “Grandmother Lesion”: Serous cystadenoma • Location • Head/neck for serous & side branch IMPN • Body/tail for mucinous cystic neoplasm • Calcification • Peripheral in mucinous cystic • Central in serous cystadenoma • Mural Nodularity (enhancement = neoplasm) • Duct communication (narrow neck) favors IPMN From Stat Dx: Cystic Pancreatic Mass & Seminars in US, CT & MRI 2007; 28: 3389-356