Radiological Analysis of Cystic lesions of the Pancreas

Transcription

1 September 2002 Radiological Analysis of Cystic lesions of the Pancreas Shruthi Mahalingaiah, Harvard Medical School Year III,

2 Agenda Background Anatomy and histology Radiological workup of a cyst in the pancreas Patient presentations Summary 2

3 Background % of all cancers are pancreatic % deaths from pancreatic cancer 5-10% of all pancreatic neoplasms are of the cystic variety 3 Adapted from Landis, SH, et al: Cancer Studies. CA 48:6, 1998

4 The Pancreas: Anatomy Here lies the fickle romance of the abdomen; the pancreas lies with her head in the arms of the duodenum while her feet tickle the spleen. NJ Mizeres 4 Plate255 Netter s Atlas of Human Anatomy

5 The Pancreas: Anatomy Retroperitoneal Hidden Virtually impossible to palpate Radiographic studies allow greater visualization and understanding of disease of the pancreas 5 Plate279 Netter s Atlas of Human Anatomy

6 The Pancreas: Ductal Anatomy Pancreatic ductal system forms from dorsal and ventral buds Wirsung and Santorini named after fusion Failure of fusion results in Pancreas divisum, which increases susceptibility to pancreatitis 6 Plate279 Netter s Atlas of Human Anatomy

7 The Pancreas: Ductal Anatomy 2.5-3L of alkaline fluid daily Ave 15 cm in length Apposed to duodenum, stomach, spleen, great vessels 7 Plate279 Netter s Atlas of Human Anatomy

8 The Pancreas: Histology Large reservoir of both endocrine and exocrine function. Disease becomes symptomatic only when severe impairment occurs 85% exocrine 8 Gartner, LP, Hiat, JL, Color Atlas of Histology

9 Cystic lesions of the Pancreas Retention Cysts Pseudocysts Cystic Neoplasms 9

10 Cystic lesions of the Pancreas Retention Cysts: No clinical significance Small, developmental, fluid filled, lined by normal duct or acinar cells. Pseudocysts Cystic Neoplasms 10

11 Cystic lesions of the Pancreas This fifteen minute presentation focuses on cystic pancreatic neoplasms with a brief discussion of pancreatic pseudocysts. For further discussion of general cystic lesions and a more encompassing differential, please refer to the reference section. 11

12 Cystic lesions of the Pancreas: Pseudocyst Pseudocysts secondary to inflammation and necrosis located within or outside the pancreas Lining contains fibrous and granulation tissue Lack of epithelial lining Present >6wks 12 from ACR teaching files

13 Cystic lesions of the Pancreas: Pseudocyst Pseudocysts Pyloric Antrum Remarkably distended C-loop of duodenum Large Mass CT for further evaluation 13 from ACR teaching files

14 Cystic lesions of the Pancreas: Pseudocyst Pseudocysts Secondary to pancreatitis Variable size located within or outside the pancreas Present >6 wks 14 John Kruskal, M.D, Ph.D, uptodate.com

15 Cystic Neoplasms of the Pancreas Serous: Microcystic Cystadenoma/ cystadenocarcinoma Mucinous: Macrocystic Cystadenoma/ cystadenocarcinoma Intraductal papillary mucinous tumor (IPMT) Zebras 15

16 Survey of 9 Patients with Cystic Disease 7/9 cystic lesions were incidental findings 4/9 MRI 2/9 US 1/9 CT CT is often initial modality in which neoplastic cyst is found. 2/9 lesions in pancreas were suspected from patients history 16 Silas, AM, Morrin, MM, Ratatopoulos, V, Keogan, MT, Intraductal Papillary Mucinous Tumor, AJR. 176(1):179-85, 2001, Jan

17 Work-up of an incidental cyst Cyst found incidentally CT US ERCP MRI Focused Radiological Study 17

18 Work-up of an incidental cyst Cyst found incidentally Focused Radiological Studies CT provides density of differentiation of intraductal and cystic spaces Septa may be appreciated with contrast enhancement Sensitive to Ca+ can detect pathognomonic stellate calcific lesion of serous cystadenoma Allows for non-invasive CT follow up 18

19 Work-up of an incidental cyst Cyst found incidentally Focused Radiological Study Ultra Sound Non-invasive More sensitive for finding septa than CT Often used for follow up of pseudocyst US guided biopsy Fast, cheap Operator dependent 19

20 Work-up of an incidental cyst Cyst found incidentally Focused Radiological Study ERCP clarifies non-specific findings Visualize filling defects Observe mucinous extrusions from ampulla of Vater in cases of IPMT Allows sampling of ductal lining cells Risk of pancreatitis 20

21 Work-up of an incidental cyst Cyst found incidentally Focused Radiological Study MRI Non-invasive Better display of subtle abnormalities- of complex cystic masses, cavities, septae, and nodules MRCP may be able to replace ERCP in the future 21

22 Work-up of an incidental cyst Cyst found incidentally Focused Radiological Study DDX Fluid Aspiration/Tissue Biopsy 22 fluid thin and watery Multiple small or microcysts Enzyme rich Hx-recent pancreatits Mucinous aspirate One or macrocystic spaces

23 Serous Cystadenoma/ Cystadenocarcinoma Second most common cystic tumor of the pancreas Middle aged women Equal distribution throughout the pancreas Mass may be quite large and produce symptoms from organ displacement. Microcystic: Many small cysts lined by glycogen-rich cells Lining is often denuded Low malignant potential 23

24 Patient KS 65 y/o female with epigastric pain, nausea, and vomiting. 24

25 Abdominal Plain Film Patient KS Stellate calcification Possibly renal Possibly pancreatic CT for further eval. 25 Courtesy: Dr. H. Gramm

26 Computational Tomography (CT) of the Abdomen Patient KS Stellate calcification in pancreas tiny cysts in a large multilobulated mass lesion Some cysts are confluent 26 Courtesy: Dr. H. Gramm

27 Reconstruction CT of the Abdomen Patient KS Symptoms from mass effect impingement on stomach and duodenum 27 Courtesy: Dr. H. Gramm

28 Correlation of KUB to CT Patient KS Serous Cystadenoma Microcystic 28 Courtesy: Dr. H. Gramm

29 Radiological Parameters of Serous Cystadenoma At least 4-6 cm If multiloculated contains no more than 6 loculations each less than 2cm Highly vascular on angio Lined with evenly spaced, flat, cuboidal to polygonal cells Cyst contains abundant glycogen 29 Serous Cystadenoma Microcystic Courtesy: Dr. H. Gramm

30 Correlation of KUB to CT Patient KS Serous Cystadenoma Microcystic 30 Courtesy: Dr. H. Gramm

31 Mucinous Cystadenoma/ Cystadenocarcinoma Most common cystic neoplasm of the pancreas Typically affects middle aged women Occurs in in body or tail of pancreas Presents with a mass lesion composed of one or more macrocytic spaces Lined by mucous secreting cells Lining is often denuded (hence difficult to make diagnosis even with pathology) High malignant potential Most are malignant at time of diagnosis 31

32 Patient MG 45 y/o woman with abdominal pain 32

33 * Single Contrast Barium Study Patient MG * * Body of Stomach * Antrum of stomach Impressive displacement of Small Bowel to RLQ CT for follow up Eval. 33 Courtesy: Dr. H. Gramm

34 Abdominal CT Patient MG * unilocular cyst No septa! Thin rim No fat stranding in surroundings 34 Courtesy: Dr. H. Gramm

35 Correlation of Single-contrast Ba and CT Patient MG * Mucinous cystadenoma Macrocystic 35 Courtesy: Dr. H. Gramm

36 Gross Pathology Patient MG * From: Mucinous cystadenoma Macrocystic 36 Courtesy: Dr. H. Gramm

37 Intraductal Papillary Mucinous Tumor (IPMT) mucinous duct ectasia Dilated ductal segments usually within the head of the pancreas Hyperplasia and dysplasia of mucin producing columnar epithelium. Formation of papillary projections may either protrude into pancreatic duct or remain in branch ducts Duct obstruction from mucin plug or compression from cystic mass High malignant potential More common in elderly men Can have thick mucous extruding from ampulla of Vater Patients can present with repeat episodes of pancreatitis 37

38 Patient JT 45 y/o male with abdominal pain 38

39 Computational Tomography (CT) of the Abdomen Patient JT Pancreas Cyst Dilated duct of Wirsung communicates with cyst Lumen of duodenum 39 Courtesy: Dr. H. Gramm

40 Endoscopic Retrograde Cholangiopancreatography Patient JT Reveals Cyst Filling defects Typically can obs. Mucin extruding from Papilla of Vater 40 Courtesy: Dr. H. Gramm

41 Correlation of (ERCP) with CT Patient JT IPMT-Main Type Pancreas Cyst 41 Courtesy: Dr. H. Gramm

42 Malignancy Highly Suspected: Filling defects Diffuse main duct dil > 15mm Side branch > 3 cm Radiological Parameters for IPMT IPMT-Main Type Pancreas Cyst 42 Courtesy: Dr. H. Gramm

43 IPMT Variants Main Type Main pancreatic duct +/- side branch involvement consider resection Side Brianch Type Side branch involvement only if lesion is less than 2.5 cm follow up with MRI 43

44 T1 W MRI Side Branch Variant 44 Courtesy: Dr. M. Morrin

45 T1 W MRI Side Branch Variant * * Liver * * * *IVC *Aorta *SMA Pancreas (fat bright; fluid dark) 45 Courtesy: Dr. M. Morrin

46 Ultrasound Side Branch Variant Cysts on side branches Not communicating with main pancreatic duct 46 Courtesy: Dr. M. Morrin

47 47 Mucin Producing Zebras of the Rare cystic neoplasms also included in differential: Papillary Cystic Tumor of the pancreas Cystic Islet Cell tumor Pancreatic Sarcoma Pancreatic Cysts associated with Von Hippel-Lindau Very Rare Cystic teratoma (very rare) Enteric cyst of the pancreas (very rare) Lymphoepithelial cysts Cystic lymphangioma Pancreas

48 Pseudocysts Cystic Neoplasms: Serous cystadenoma Mucinous Cystadenoma/ cystadenocarcinoma Intraductal papillary mucinous tumor Imaging Modalities Cystic lesions of the Pancreas: Summary 48

49 References Feldman: Sleisenger & Fordtran s Gastrointestinal and Liver Disease, 6 th ed., 1998: WB. Saunders, p Grogan JR, Saeian K, Taylor AJ, Quiroz F, Demeure MJ, Komorowski R. Making Sense of Mucin Producing Pancreatic Tumors. AJR 2001; 174(4): Gartner JP, Hiatt JL. Color Atlas of Histology, 2 nd ed., 1994: Williams and Wilkins, p.280. Silas AM, Morrin MM, Raptopoulos V, Keogan MT. Intraductal Papillary Mucinous Tumors of the Pancreas. AJR 2000; 176: Netter, FH. Atlas of Human Anatomy, 2 nd ed., 1997:Novartis, plates: 255, 279. Steer, MJ. Cystic Lesions of the Pancreas, June 11,2002 (last updated) Van Houten T, et al. Anatomy Dissector, 2002: Unpublished. Chapter 12: Biliary System, Pancreas, and Spleen. 49

50 Acknowledgements Dr. Herbert Gramm, MD Dr. Robert Ronan, MD Dr. Martina Morrin, MD Dr. Chad Brecher, MD Dr. Early morning gang-james, Eduardo, Jon Pamela Lepkowski Michael Larson Larry Barbaras and Cara Lyn D amour 50