Digestive System Disorders: Cases and Diagnoses Directory

1. GI Cases 1-25

2. Case directory

3. Case 1

5. Caroli’s disease • Case findings: • Multifocal segmental saccular dilatation of the intrahepatic bile ducts • Several round and oval hypodense cystic structures containing air-fluid levels, which communicate with intrahepatic bile ducts • Associated with: • Congenital hepatic fibrosis • Medullary sponge kidney • ARPKD • DDX intrahepatic biliary cystic dilatation: • Sclerosing cholangitis • Choledochal cyst • Caroli’s disease • Cholangiocarcinoma (Klatskin tumor)

6. Case directory Choledochal cyst • Type 1: MC, fusiform dilatation of CBD • Type 2: diverticulum of CBD • Type 3: dilatation of intraduodenal portion of CBD (choledochocele) • Type IV: • Type IV-a: intrahepatic and extrahepatic ductal dilatation • Type IV-b: extrahepatic ductal dilatation • Type V: Caroli’s disease (MC intrahepatic ductal dilatation)

7. Case 2

8. Mesenteric panniculitis (mesenteric lipodystrophy, idiopathic retractile mesenteritis) • Case findings: • Irregular mesenteric mass with central calcifications and radiating desmoplastic reaction exhibiting fibrotic tenting of adjacent loops of SB • Fibrotic reaction is causing partial SBO • MC small bowel, but may involve colon • CT: varies from ST attenuation mesenteric infiltration to well-defined ST masscontaining interspersed fat • If fibrotic component predominates, DDX: • Neoplastic disease • Carcinoid tumor

9. Case directory Mesenteric panniculitis (mesenteric lipodystrophy, idiopathic retractile mesenteritis) • Characterize different stages of a pathologic process that results in fibrofatty thickening of the mesentery • Panniculitis: primary component is inflammatory • Lipodystrophy: when fatty degeneration predominates • Retractile mesenteritis (or sclerosing mesenteritis): when the predominant component is fibrosis • MC idiopathic, fat necrosis can be caused by infection, recent surgery, or a foreign body • Degeneration and necrosis of fat eventually leads to extensive fibrosis

10. Case 3

11. Case directory Pancreatic lipomatosis • Case findings: • No identifiable pancreatic parenchyma • No loss of retroperitoneal volume to suggest prior pancreatectomy • Fatty replacement of the pancreas (lipomatosis) is common and increases in incidence with age • DDX: • Pure pancreatic atrophy (e.g. chronic pancreatitis, cystic fibrosis) • Congenital pancreatic hypoplasia (Schwachman syndrome) • History of pancreatic resection

12. Case 4

14. Cholangiocarcinoma • Case findings: • Left biliary tree is not opacified and there is a tight stricture (near occlusion) at the origin of the CBD • 2nd MC primary hepatic tumor (after HCC), slow growing, MC adenocarcinoma • Risk factors: choledochal cyst, UC, Caroli’s disease, Clonorchis sinensis infection, PSC • Klatskin tumor: located at the bifurcation of main biliary ducts

15. Case directory Cholangiocarcinoma • Features: • Large at presentation, hypoattenuating, with irregular margins • Delayed enhancement with increasing attenuation (used to differentiate between HCC) • DDX: • Metastasis • HCC • Sarcoma

16. Case 5

17. Splenic hamartoma • Case findings: • Hypervascular, heterogeneous mass in the posterior aspect of the spleen which exerts mass effect on the left kidney • Mass is hyperdense in the arterial phase and isodense to splenic parenchyma on non-contrast and portal venous phases • Hypodense areas within the mass which may represent cystic components or necrosis

18. Case directory Splenic hamartoma • Also called splenomas, or nodular hyperplasia of the spleen • Benign, associated with tuberous sclerosis • Malignant splenic tumors (lymphoma, mucinous cystadenocarcinoma, metastases)  MC hypodense and avascular • Complication: splenic rupture • DDX hyperdense splenic mass: • Cavernous hemangioma • Splenic hamartoma • Hemangioendothelioma • Malignant fibrous histiocytoma • Inflammatory pseudotumor

19. Case 6

20. Juvenile polyposis • Case findings: • Multiple large lobulated filling defects within the cecum extending into the ascending colon • AD, but can also occur de novo • Polyps are hamartomatous, but there is a risk of malignant transformation (9-50%) • MC type of related cancer is colon cancer (LC gastric and pancreatic cancers) • Presentation of JP is MC with GI bleeding

21. Case directory Polyposis syndromes • Hamartomatous polyps: • Cowden (multiple hamartoma syndrome): associated with breast and thyroid cancer • Peutz-Jeghers • Multiple hamartomas  MC stomach • Mucocutaneous hyperpigmentation • Adenomatous polyps: • Familial polyposis coli • Turcot: associated with brain tumors (GBM, medulloblastoma) • Gardner’s syndrome: colonic polyps, osteomas (frontal sinus, mandible), ST tumors (desmoid tumors, epidermoid inclusion cysts, fibroma, lipoma, leiomyoma) • Juvenile polyps: • Juvenile polyposis coli • Cronkite-Canada: inflammatory juvenile polyps

22. Case 7

23. Visceral artery aneurysms (VAA) • Case findings: • Fusiform aneurysm of the proper and common hepatic arteries • Narrowing of the lumen of the aneurysm due to thrombus; however flow is demonstrated within the aneurysm • Left hepatic artery is thrombosed (not shown)

24. Case directory Visceral artery aneurysms (VAA) • MC splenic artery aneurysms (60%) • Hepatic artery aneurysms: • Intrahepatic aneurysms: • MC secondary to trauma • LC polyarteritis nodosa, infusion of chemotherapeutic drugs, CVD • Extrahepatic aneurysms: • MC solitary, atherosclerosis degeneration

25. Case 8

27. Cholangiocarcinoma (Klatskin tumor) • Case findings: • HASTE coronal image from MRCP: marked bilateral intrahepatic biliary dilatation with an approximately 2 cm focal stricture of the CBD • Percutaneous transhepatic cholangiogram: confirms findings seen at MRCP • DDX: • Cholangiocarcinoma • Benign stricture (iatrogenic) • Sclerosing cholangitis

28. Case directory Cholangiocarcinoma (Klatskin tumor) • Classic: • Infiltrative process, a discrete mass may not be evident • Focal or long-segment strictures, or LC an intraluminal mass • Biliary dilatation proximal to the tumor is often present • Rare tumor of the biliary tree • Associated with: Chlonorchis infection, UC, PSC • Klatskin tumor: refers to cholangiocarcinoma at the confluence of the right and left hepatic ducts

29. Case 9

30. Case directory Femoral hernia • Case findings: • Loop of small bowel within a right femoral hernia • Note that the femoral hernia is medial to the femoral vein where the femoral canal lies • Proximal SBO with markedly dilated loops • Groin hernia: • MC inguinal (95%), LC femoral (5%) • Protrusion through the femoral ring into the femoral canal • Femoral hernia is medial to femoral vein • Prone to incarceration and strangulation

31. Case 10

33. Case directory Acute pancreatitis • DDX: • Pancreatic pseudocyst • Pancreatic carcinoma • Extrinsic mass effect on the posterior portion of the stomach by an enlarged pancreas or pseudocyst • Widening of the duodenal sweep • DDX of medial duodenal mucosal irregularities: • Edema • Inflammation • Spread of pancreatic carcinoma

34. Case 11

36. Pneumatosis intestinalis

37. Pneumatosis intestinalis

38. Case directory Pneumatosis intestinalis • Primary pneumatosis intestinalis (15%): • No disease process is present and occurs mainly in adults and involves the colon • No treatment and resolves spontaneously • Secondary pneumatosis intestinalis (85%): • MC small bowel • Associated with: • Ischemia, obstruction, infection (NEC in infants), PUD, IBD • Status post endoscopy, colonoscopy, or surgery. • Obstructive lung disease • Systemic conditions: leukemia, GVHD, corticosteroid therapy

39. Case 12

40. Omental infarction • Case findings: • Large triangular mass between ascending colon and anterior abdominal wall • Mass is predominantly fatty, interspersed with higher attenuating linear densities • Primary torsion: mobile segment of omentum rotates around a proximal fixed point in the absence of any associated intra-abdominal pathology

41. Case directory Omental infarction • Hyperechoic on US, mixed attenuation on CT • Concentric distribution of fibrous and fatty folds converging radially toward the torsion • MC triangular shape • Mass with fibrous and fatty folds in between the anterior abdominal wall and the colon, usually RLQ • Self-limiting process

42. Case 13

43. Sclerosing encapsulating peritonitis (cocoon abdomen) • Case findings: • Multiple mid to distal small bowel are adherent and encased within a partially calcified fibrotic peritoneum • DDX: • Sclerosing encapsulating peritonitis • Infectious peritonitis with extensive mesenteric inflammation • Intra-abdominal abscess • Peritoneal mesothelioma • Pertitoneal metastases

44. Case directory Sclerosing encapsulating peritonitis (cocoon abdomen) • Complication of continuous ambulatory peritoneal dialysis (CAPD) • SB is partially or totally entrapped in a fibrous cocoon-like sac and adhesions develop between the intestinal loops • Contributing factors: duration of peritoneal dialysis and previous episodes of bacterial or fungal peritonitis

45. Case 14

46. Case directory Gallstone ileus • Rigler’s triad: • Distended small bowel loops • Pneumobilia • Ectopic gallstone

47. Case 15

49. Case directory Cecal volvulus • DDX: • Cecal volvulus  (most likely) • Sigmoid colon volvulus • Transverse colon volvulus • Internal hernia (i.e. foramen of Winslow hernia) • Features: • Distended large bowel demonstrating the coffee bean appearance with the smooth surface of the "bean" facing the LLQ • Bird-beak sign in ascending colon with a barium enema • Swirl of mesentery and cecum in RLQ with distended large bowel on CT

50. Case 16 Arterial phase Portal venous phase