CASES

1. CASES Dr Prashanth G IInd yr Resident Dept: of Radiology SSG hospital Vadodara 24 – 05 - 07

2. CASE 1 • A 50yr old man without any significant past history presented with a painless palpable lump in epigastric region.

3. CT scan shows a multiloculated cystic lesion with numerous small cystic lesions , lobulated outlines and a central scar. No vascular encasement noted.

4. DDs of cystic pancreatic lesions • Pseudocyst • Serous cystadenoma • Mucinous cystadenoma/carcinoma • Intraductal Papillary Mucinous Neoplasms ( IPMN ) • Solid lesions with cystic component / degeneration. • Other than pseudocyst, 2,3 & 4 constitute 90% cases.

5. Discussion • First step is to exclude pseudocyst – pts generally have h/o a/c or c/c pancreatitis. • Useful imaging modalities are CT, MRI / MRCP & endoscopic high resolution US.

6. Bosniak’s morphologic classification Cyst with a solid component Macrocystic lesion Unilocular cyst Microcystic lesion with a central scar

7. 1. Unilocular cysts • Cysts without septa, solid component or calcification. • MC – pseudocyst – a/w pancreatitis Others – difficult characterise, • IPMNs – communication with PD can be seen in MRCP, • Unilocular serous cystadenomas – usually has a lobulated contour & located in head of pancreas & • Lymphoepithelial cysts. • Irregular wall thickening of the cyst indicate an aggressive nature of the lesion.

8. CECT & HR US images in a patient with pancreatitis – well defined unilocular cystic lesion in the head of pancreas - pseudocyst

9. 2. Microcystic lesion • Only one lesion is included in this category – serous cystadenomas – benign lesions. • Contains a collection of cysts, >6 in no: , ranging from a few mm to 2cm in size. • CT – a well defined soft tissue/mixed density “spongy” lesion with lobulated outlines with sharp interface with vessels. • A central scar +/- a stellate calcification is seen in 1/3 of cases & is pathognomonic. • PD is usually not dilated.

10. 3. Macrcystic lesion • Multilocular lesions with fewer compartments of >2cm in size . • Have malignant potential. Include • Mucinous cystadenomas – mc in body & tail region, can attain bigger sizess, contain debri & hge, cause PD block & dilatation, peripheral egg shell calcification is s/o malignant change. • IPMN – premalignant lesions seen as a septated cyst communicating with MPD in MRCP. • Non functioning neuroendocrine tumors & lymphangiomas.

11.  .Contrast-enhanced CT scan shows a large cystic mass with internal septa in the head of the pancreas. The peripheral and septal calcifications (arrowheads) indicate the malignant nature of the lesion - Mucinous cystadenocarcinoma

12. Axial CECT scan shows a multiseptated cystic lesion with thin septa in head of pancreas. High-resolution endoscopic US image demonstrates the septated internal architecture of the cyst - Mucinous cystadenoma

13. 3. Cysts with a solid component • Can be uni/multilocular, all are either malignant or have high malignant potential. • Include mucinous neoplasms, IPMNs & solid tumours with cystic component / cystic degeneration like adenocarcinoma, islet cell tumours, solid pseudopapillary tumours & mets.

14. . CT scans and HR endoscopic US image obtained in a patient shows a cystic lesion in the pancreatic body with peripheral mural nodules - Islet cell tumor with a solid component

15. DIAGNOSIS In our case there is a microcystic lesion with lobulated margins & having a calcified central scar suggesting the diagnosis of Serous Cystadenoma.

16. CASE 2 • 20 years old female presenting with a painless, palpable, mobile, central abdominal lump. • No other complaints. • Past & family histories are not significant.

17. Transverse US images showing a well defined cystic lesion with lobulated borders & internal septations arising from region of mesentery.

18. Axial CECT image shows that the mass is originating from mesetery & is lobulated, of low attenuation that of fluid-fat, and nonenhancing.

19. DDs • The various fat containing lesions of the mesentery are the possibilities: * Lymphangioma. * Lipoma / Liposarcoma * Cavitating Lymphnode Syndrome.

20. LIPOMA & LIPOSARCOMA • Benign lipomas consist predominantly of fat, which is reflected in their CT attenuation and MR signal characteristics. They also have thin septae within. • Liposarcomas are rarely seen in mesentery ; CT and MR characteristics depends on the histologic subtypes. • Multiple subtypes can be seen in the same lesion also.

21. Well differentiated lipomatous LSA are fat density lesions with internal septae which are thicker, irregular & nodular than that of a lipoma. • Sclerosing LSA: smooth muscle density. • Myxoid LSA : has an appearance on unenhanced CT that is similar to water, with reticular enhancement after administration of intravenous contrast material.

22. Axial CECT of abdomen shows a well defined rounded fat density lesion arising from mesentery s/o a lipoma of mesentery.

23.   Axial contrast-enhanced CT image shows a well-defined, slightly heterogeneous mass with fatty components in the mesentery, causing anterior displacement of the small intestine.The thin, fibrous internal septa of soft tissue attenuation suggest the diagnosis of liposarcoma.

24. Cavitating Mesenteric Lumphnode Syndrome • CMLS is a fatal condition found in patients with celiac sprue as fat-containing mesentenic nodal masses . • Asso: splenic atrophy & intestinal villous atrophy are present. • C/F – diarrhea, malabsorption, abd mass & f/o small bowel obstruction.

25. Axial CECT abdomen in a pt with Coeliac sprue showing multiple nodal masses with fat-fluid levels – a c/o CMLS

26. Lymphangiomas • Predominant in younger people, thought to be due to congenital obstruction of lymphatics. • Commonly present with a palpable mass. • Can cause bowel obstruction by extrinsic compression / volvulus. • US – well defined anechoic cystic lesion; septations , honeycoomb pattern & solid components are also seen. • CT – well defined thin walled uni / multilocular mass with / without septae having attenuation of fluid – fat & other contents.

27. Axial unenhanced and coronal contrast-enhanced CT scans in a 40yr old women show an unenhancing lobulated cystic mass with areas of fat attenuation in the greater omentum inferior to the gastric antrum – was an incidental finding & was later proved to be a cystic lymphangioma.

28. Diagnosis We have a c/o unenhancing lobulated septated cystic lesion arising from mesentery with areas of fat attenuation in a young female presenting with painless abd lump - Lymphangioma

29. CASE 3 • A 9-year-old female child presented with history of fever, jaundice, pain and lump in the right hypochondrium of 15 days duration. • On examination the liver was palpable 4 cm below the right costal margin. • Biochemical investigations revealed leucocytosis, raised serum bilirubin & other liver enzymes esp. alkaline phosphatase.

30. US iamge showing a large cystic mass at the porta medial & separate to GB. The mass is contiguous & appears to connect with slightly prominent CBD & is separate from pancreatic head.

31. Coronal MRCP image shows choledochal cyst that is causing dilatation of proximal common bile duct and short segmental dilatation of distal common bile duct (arrow).

32. CT image showing a large extrahepatic saccular, cystic mass and the adjacent gallbladder.

33. Intraoperative cholangiogram shows choledochal cyst that is concordant with that shown on MRCP. Arrow shows a stricture btw two lesions.

34. Diagnosis Type IV b Choledochal Cyst

35. Discussion • A choledochal cyst is a dilatation of any component of the biliary tract that may include both intra and extra-hepatic sites • Generally seen in childhood with 60% cases in <10yrs of age. • Females three to four times more commonly affected than males. • Clinical triad – abd pain, jaundice and abd mass. The classical triad is seen in 30-60% of pts in first decade of life.

36. ANOMALOUS PANCREATICOBILIARY DUCTAL FORMATION Pressure in the PD exceeds that of CBD, allowing the flow of pancreatic juice into the bile ducts Repeated bouts of Cholangitis Destruction of the CBD wall combined with distal stenosis of the wall because of fibrosis dilatation of the CBD Choledochal cyst

37. Classification by Todani et al TYPE I: Most common (80-90 %). I A cystic dilatation of the CBD I B Focal segmental dilatation of the CBD, usually the most distal part of the duct I C Fusiform dilatation of both the common hepatic and CBD.

38. TYPE II • Cyst is a choledochal diverticulum TYPE III • Choledochocele (intra duodenal portion of the CBD)

39. Type IV Type V IV B Dilatation of multiple segments confined to extra hepatic bile duct IV A Cyst involves dilatation of intrahepatic and extrahepatic bile ducts TYPE V Carolis disease Dilatation of one or several segments of intra hepatic bile ducts

40. The role of imaging in the evaluation of choledochal cyst is • To delineate the anatomy of the cyst, • Determine the relationship of the cyst to the rest of the intra and extrahepatic biliary tree & • Evaluate associated complications and biliary tree abnormalities.

41. Sonography: • Is the method of choice in the initial evaluation of choledochal cyst. • It cannot reveal anomalous pancreaticobiliary ductal union, which is generally believed to be a cause of choledochal cyst.

42. Transverse sonogram in a 6-year-old girl with jaundice shows a 4-cm anechoic cyst in the region of the pancreatic head. Color Doppler image shows absence of flow in the dilated CBD, which communicates with the cyst - Choledochal cyst (type IA).

43.   (a) Sagittal sonogram in a female neonate with jaundice shows a fusiform choledochal cyst involving the common bile duct. The surrounding hepatic echotexture is coarse. (b) Intraoperative cholangiogram demonstrates a small gallbladder (GB) and atretic intrahepatic biliary radicals & the choledochal cyst (CC) - Choledochal cyst (type IC) with biliary atresia

44. ERCP : • ERCP is regarded as the most definitive and reliable diagnostic method of revealing anomalous pancreaticobiliary ductal union. • However, ERCP is contraindicated in patients with acute pancreatitis and cholangitis and requires the administration of general anesthetic in children.

45. Intraoperative cholangiogram in a 3yr old girl with jaundice & abdominal pain shows cystic dilatation of the intra- and extrahepatic bile ducts. The intrahepaticbile ducts have a beaded appearance .The pancreaticobiliary ductal union is right angled & the common canal is long & stenotic – Type IV a choledochal cyst.

46. ERCP image shows marked cystic dilatation of the proximal part of thecommon bile duct and areas of lesser dilatation in the distal part of the duct. The segments ofcommon bile duct between the cysts are stenotic - Type IVB choledochal cyst .

47. MR cholangiopancreatography: • A safe substitute for ERCP. • The cysts appear as large fusiform or saccular masses that may be extrahepatic, intrahepatic, or both, depending on the type of cyst. • They produce a particularly strong signal on T2WI. Associated anomalies of the pancreatic duct, its junction with the common bile duct, and the long common channel formed by the two are usually well demonstrated on MRI / MRCP images. • Advantages - it does not require breath holding, is noninvasive, does not require the administration of contrast material.

48. Coronal MRCP image obtained in a 7-month-old male infant with cholestasis. reveals intra- and extrahepatic biliary dilatation, as well as focal intrahepatic biliary cystic dilatations - A type 4a choledochal abnormality was pathologically confirmed. g = gallbladder.

49. Abdominal CT : • CT is highly accurate & is helpful not only in confirming the diagnosis but also in planning surgical approaches. • Satisfactory visualization of the biliary tree is achieved in 93% of patients by using CT cholangiography

50. Hepatobiliary scintigraphy : • Using Tc-99m desferin confirms the biliary origin of the cyst • Appears as • Group of photopenic area in the porta which is gradually filled by radionuclide on later images • Stasis of agent in dilated bile ducts and non visualisation of radionucleide bowel activity.