Abdominal Flashcards
Peritoneal calcifications
- cystadenocarcinoma of the ovary: fine sand-like calcification
- pseudomyxoma peritonei: often ring or arc-like calcifications, most numerous in the pelvis
- undifferentiated abdominal malignancies: dystrophic calcification within the tumour masses
- tuberculous peritonitis (tuberculosis) - pneumocystis carinii infection
- hyperparathyroidism
- in newborns: meconium peritonitis
- secondary to continuous ambulatory peritoneal dialysis (CAPD)
- post-operative heterotopic ossification
Gardner syndrome
Gardner syndrome is one of the polyposis syndromes. It is characterised by: familial adenopolyposis multiple osteomas: especially of the mandible, skull, and long bones epidermal cysts fibromatoses desmoid tumours of mesentery and anterior abdominal wall Other abnormalities include: supernumerary teeth and odontomas 4 duodenal tumours / ampullary carcinoma 2,3 papillary thyroid carcinoma
Epiploic appendagitis
self-limiting ischaemic/inflammatory process involving appendix epiploica of the colon and may either be primary or secondary to adjacent pathology.
Bouveret syndrome
Bouveret syndrome refers to a gastric outlet obstruction secondary to impaction of a gallstone in the pylorus or proximal duodenum. Thus, it can be considered a very proximal form of gallstone ileus.
Gamna–Gandy bodies
Gamna–Gandy bodies are splenic microhemorrhages, which appear hypointense on GRE. It’s a secondary manifestations of cirrhosis.
Multiple biliary hamartomas (von Meyenburg complexes)
Multiple biliary hamartomas (MBHs) are a rare cause of multiple benign hepatic lesions. The condition is also known as von Meyenburg complexes, multiple bile duct hamartomas or biliary microhamartomas. Multiple biliary hamartomas are asymptomatic and usually found incidentally, when it is important to differentiate them from other causes of multiple liver lesions, particularly metastases.
Choledochal cyst classification
- I - fusiform CBD dialation
- II - extrahepatric saccular dilation
- III - intraduodenal bile duct dilation
- IV - multiple dilations (a: intra- and extrahepatric; b: extrahepatic only)
- V - intrahepatic dilations = Caroli disease
when combination of small bile ducts dilatation and congenital hepatic fibrosis = Caroli syndrome
increased cholangiocarcinoma risk
emphysematous cholecystitis
- acute cholecystitis complication in elderly diabetic
- caused gas-forming bacteria
- gas in the lumen or the wall of the gallbladder
Gangrenous cholecystitis
Gangrenous cholecystitis is the most common complication of acute cholecystitis: wall ischaemia and necrosis.
- intraluminal membranes
- asymmetrical wall thickness
- with possible wall disruption and/or ulceration
- variable absence of the sonographic Murphy’s sign attributed to ischaemic denervation of the gallbladder
Porcelain gallbladder
Charcot’s triad
- fever
- abdominal pain
- jaundice
in ascending cholangitis
Primary sclerosing cholangitis (PSC)
- beaded, irregular bilde ducts appearence
- PSC is an idiopathic condition with inflammation and destruction of the bile ducts.
- results in multiple strictures, liver damage, and eventually cirrhosis.
- assosciated with ulcerative colitis.
primary biliiary cirrhosis
inflammation and destruction of smaller bile ducts than in PSC.
middle-aged women, presents with pruritus, may lead to cirrhosis.
AIDS cholangitis
Like PSC, however papillaryy stenosis is present
Biliary cystadenoma
Biliary cystadenoma benign cystic neoplasms of the liver in middle-aged. Either unilocular or multilocular. Only rarely are they found in the extrahepatic biliary tree and gallbladder.
CT arterial phase
Extensive intrahepatic biliary dilatation caused by an expansile CBD heterogeneously enhancing lesion which is invading the liver.
Right portal vein appears severely narrowed, highly suspicious of tumour invasion. (CT portal phase below)
extensive CHOLANGIOCARCINOMA
Cholangiocarcinoma
- malignant tumours arising from cholangiocytes in the biliary tree and are the second most common primary hepatic malignancy after hepatocellular carcinoma (HCC).
- presents with painless jaundice
- Risk factors:
- Caroli disease / choledochal cyst
- choledocholithiasis more than cholelithiasis
- primary sclerosing cholangitis (PSC)
- recurrent pyogenic cholangitis (hepatolithiasis)
- cirrhosis
- toxins
- viral infections
- intrahepatic in 20% of cases, extrahepatic in 80%
Cholangiocarcinoma - types
intrahepatic - 20%; extrahepatic - 80%
-
Mass-forming
- Intrahepatic, exophytic, nodular (peripheral) tumours are most commonly of the mass-forming type
- They demonstrate variable amounts of central fibrosis, usually marked.
-
Periductal infiltrating
- Most common at the hilum (over 70%), where they are known as Klatskin tumours
- they can also be seen in combination with mass-forming tumours within the liver.
- Growth along the walls of the duct may narrow or dilate the duct.
-
Intraductal
- Alterations in duct calibre, usually duct ectasia with or without a visible mass.
- If a mass is visible it may be mural or polypoid in shape.
- The duct dilatation is thought to be due to abundant mucin production. This entity is thought to be similar to the pancreatic intraductal papillary mucinous neoplasms (IPMN).
-
Extrahepatic/large duct
- These tumours are most commonly infiltrating, although both exophytic (mass-forming) and polypoid (intraductal) types are identified. They have similar appearances to their intrahepatic counterparts.
Imaging of cholangiocarcinoma
Mass-forming cholangiocarcinomas:
- homogeneously low in attenuation on noncontrast scans
- heterogeneous minor peripheral enhancement with gradual centripetal enhancement.
- capsular retraction may be evident (helpful in distinguishing cholangiocarcinomas from other hepatic tumours.)
- bile ducts distal to the mass are typically dilated.
- unlike HCC, cholangiocarcinoma only rarely forms a tumour thrombus.
Periductal infiltrating:
- intrahepatic tumours appear as regions of duct wall thickening or of the periductal parenchyma, with altered calibre of the involved duct (usually narrowed).
- most common at the hepatic hilum.
- longer than benign strictures (i.e. approximately 20 mm in length)
- contrast enhancement.
- peripheral dilatation of the biliary tree.
Intraductal tumours:
- alterations in duct calibre
- usually duct ectasia with or without a visible mass.
- If a polypoid mass is seen it is hypoattenuating on pre-contrast imaging and demonstrates enhancement.
DWI/ADC: a peripherally hyperintense “target” appearance on DWI favours cholangiocarcinoma over hepatocellular carcinoma
gallbladder metastasis
melanoma
double duct sign
dialtion of both pancreatic and common bile ducts.
even if no mass still suspicious of adenocarcinoma.
small mass is located in the uncinate process of the pancreas with a preserved fat plane around the superior mesenteric artery and veins. Both the biliary tree and pancreatic duct are dilated. A prominent coeliac node is also present. Incidental splenunculi.
Pancreatic ductal adenocarcinoma
Hereditary syndromes with increased risk of pancreatic ductal adenocarcinoma
- Hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome)
- familial breast cancer
- familial atypical multiple mole melanoma (FAMMM)
- hereditary pancreatitis
- ataxia-telangiectasia
- Peutz-Jeghers syndrome
Acinar cell carcinoma
- rare, aggressive cariant of pancreatic adenocarcinoma
- in elderly males
- produces large amounts of lipase, which leads to:
- subcutaneous fat necrosis
- bone infarcts leading to polyarthralgias
- eosinophilia
Serous cystadenoma
- “grandmother tumor”
- > 6 cyst, < 2 cm
- hypervascular pancreatic tumor (specific)
- doesn’t cause pancreatic duct dilation or tail atrophy
- central stellate calification
hypervascular pancreatic tumor
serous cystadenoma (grandmother tumor) or neuroendocrine tumors
serous cystadenoma
central calcifications
most common cystic neoplasm of the pancreas
Mucinous cystic neoplasms of the pancreas
Mucinous cystadenomas (MCN) of the pancreas
- “mother tumor”
- malignant potential
- few (< 6), large (> 2 cm) cysts
- in the pancreatic body or tail
- has a capsule (the other pancreatic tumor woth capsule is SPEN)
mucinous cystadenoma (mother tumor)
Solid pseudopapillary epithelial neoplasm (SPEN)
- SPEN = Frantz tumor = daughter tumor
- mostly benign, ~15% can be malignan
- well-encapsulated lesion with varying solid and cystic components owing to haemorrhagic degeneration
Intraductal papillary mucinous neoplasm (IPMN)
- IPMN
- more often in elderly males, but in females as well - grandfather tumor
- benign or malignant
- main duct location - 60% are malignant
- cystic intrapancreatic lesion in contiguity with the main duct or a side branch
- if nodular or enhancing component - concern for malignancy
- main duct IPMN (with dilatation of the main duct >5 mm)
- either segment of the pancreatic duct (or the entire duct) are dilated and filled with low density (mucin thus water signal) material
- branch duct IPMN
- single or multiple side branches demonstrating marked dilatation
cystic mass-like appearance which often mimics cystic tumours of the pancreas
* its appearance has been termed a bunch of grapes due to its appearance * microcystic variety has appearances similar to serous cystadenomas, but again communication with the main pancreatic duct is the key to the correct diagnosis
IPMN DDx
DDX:
chronic pancreatitis - difficult to distinguish from main duct type on account of dilated duct
mucinous cystadenoma/cystadenocarcinoma - should not appear to communicate with the main pancreatic duct
serous cystadenoma - should not appear to communicate with the main pancreatic duct, may appear similar to microcystic branch type IPMN, 30-40% have central calcification
Fukuoka consensus guidelines, also referred to as the Tanaka criteria
Investigation
- cyst <5 mm
- asymptomatic - invasive carcinoma is rare, follow-up only
- symptomatic - further evaluation or resection
- cyst >5 mm
- pancreatic protocol CT or MRI pancreas and MRCP to evaluate
Classification
- branch duct IPMN (BD-IPMN)
- cyst >5 mm communicating with main duct
- main duct IPMN (MD-IPMN)
- dilatation of the main duct > 5 mm without other cause for obstruction
- 5-9 mm: “worrisome feature”
- ≥10 mm: “high-risk stigmata”
- mixed-type IPMN: appears like an advanced branch duct IPMN with main pancreatic duct dilatation (>5 mm)
High-risk stigmata
- enhancing solid component >5 mm
- main pancreatic duct ≥10 mm
- obstructive jaundice
Worrisome features
- cyst ≥3 cm
- thickened and enhancing cyst wall
- enhancing mural nodule <5 mm
- main pancreatic duct 5-9 mm
- lymphadenopathy
- abrupt change in calibre of the pancreatic duct with distal pancreatic atrophy
- cyst growth rate ≥5 mm in two years
- elevated Ca19-9
Insulinoma
- most common neuroendocrine pancreatic tumor
- symptoms (Whipple triad):
- hypoglicemia
- clinical symptoms of hypoglicemia
- alleviation of symptoms after glucose
Gastrinoma
- 2nd most common neuroendorine tumor
- causes hypersecretion of gastric acid resulting in Zollinger-Ellison syndrome
- associated with MEN 1 (then multiple and in the duodenum)
double bubble sign
causes:
- duodenal web
- duodenal atresia/stenosis
- annular pancreas
- midgut volvulus
- external compression of the duodenum:
- choledochal cyst
- mesenteric duplication cyst
- intramural duodenal haematoma
- preduodenal portal vein
- retroperitoneal tumour
- superior mesenteric artery syndrome
Von Hippel-Lindau disease (mnemonic)
H: haemangioblastoma
I: increased risk of renal cell cancer
P: phaeochromocytoma
P: pancreatic lesions (cyst, cystadenoma, cystadenocarcinoma)
E: eye dysfunction (retinal haemangioblastoma), endolymphatic sac tumours
L: liver, renal and pancreatic cysts
Groove pancreatitis
focal pancreatitis between the head of the pancreas, duodenu and common bile duct.
DDx - adenocarcinoma
Modified CT severity index in acute pancreatitis
Pancreatic inflammation
0: normal pancreas
2: intrinsic pancreatic abnormalities with or without inflammatory changes in peripancreatic fat
4: pancreatic or peripancreatic fluid collection or peripancreatic fat necrosis
Pancreatic necrosis
0: none
2: 30% or less
4: more than 30%
Extrapancreatic complications
2: one or more of pleural effusion, ascites, vascular complications, parenchymal complications and/or gastrointestinal involvement
Total score
Total points are given out of 10 to determine the grade of pancreatitis and aid treatment:
0-2: mild
4-6: moderate
8-10: severe
Diffuse pancreatic parenchymal enlargement predominantly affected the body and tail with decreased attenuation. Indistinct pancreatic margins with surrounding retroperitoneal fat stranding. Thickened oedematous large bowel at the hepatic and splenic flexures. Multiple peripancreatic and periportal lymph nodes.
Relative hypoattenuation of the liver to the spleen in keeping with hepatic steatosis.
multiple calcified splenic lesions
pneumocystis jiroveci in AIDS
H-shaped vertebrae
Sharply delimited central endplate depression, classically seen in approximately 10% of patients with sickle-cell anaemia, and results from microvascular endplate infarction (figure 1) 3.
It may occasionally be seen with other conditions such as Gaucher disease.
Esophageal rings
A: a few centimetres proximal to the gastro-oesophageal junction, a contraction of oesophageal smooth muscle covered by mucosa
B: B ring is a mucosal ring that develops in the distal oesophagus at the gastrooesophageal junction (Z line)
C: diaphragmatic impression
Schatzki ring: symptomatically narrow oesophageal B-ring occurring in the distal oesophagus and usually associated with a hiatus hernia.
Shwachman-Diamond syndrome
shortened extremities
cup deformity of ribs
Hyperechoic pancreas due to extreme pancreatic lipomatosis, usually with preservation of pancreatic size.
mesenchymal esophageal masses
- benign
- GIST, leiomyoma, hemangioma, others
- smooth, round, submucosal
esophageal adenoma
- benign, malignant potential
- within barrett esophagus
- < 1.5 cm
fibrovascular polyp (esophagus)
pedunculated mass with significant fatty component
Most common primary retroperitoneal tumor?
Liposarcoma
- They are usually seen in the extremities (75%), 10-15% liposarcomas arise in the retroperitoneum
- most commonly well-differentiated with high fat content
- CT findings favouring a liposarcoma over a lipoma include:
- inhomogeneous attenuation, with evidence of significant amounts of soft-tissue within the fatty mass
- poor definition of adjacent structures
- invasion of mediastinal structures
- calcification
- The higher grade lesions are often devoid of macroscopic fat and have appearances similar to other sarcomas.
(Image STIR)
Retroperitoneal fibrosis
Retroperitoneal fibrosis (RPF)
- typically presents with ureteric obstruction,
- Retroperitoneal fibrosis is visible as a soft tissue density mass located around the aorta and iliac arteries. Classically, it develops around the aortic bifurcation and spreads upwards where it can envelop the renal hila. It encases but does not invade or stenose the ureters or vessels. However, ureteric obstruction and venous thromboses can occur.
In early or active stages, variable enhancement can be seen with intravenous contrast while no enhancement may be seen in the quiescent disease.
Adrenal washout
Absolute = (enhanced-delayed)/(enhanced-unenhanced)
adenoma if >60%
Relative = (enhanced - delayed)/enhanced
adenoma if >40%
macroscopic fat in adrenal gland
myelolipoma
Syndromes associated with pheochromocytoma
von Hippel Lindau
MEN 2a and 2b
neurofibromatosis type 1
Carney’s triad - gastric leiomyosarcoma, pulmonary chondroma, extraadrenal pheo
multilocular cystic nephroma
herniation into the collecting system specific, but usually doesn’t occur and the mass cannot be differentiation from RCC
Lobste claw or ball in tree sign of papillary necrosis
Causes differential POSTCARD:
- pyelonephritis
- obstruction
- sickle cell disease
- tuberculosis
- cirrhosis
- analgesics (NSAIDs)
- renal vein thrombosis
- diabetes
medullary nephrocalcinosis
- hypercalcemic state (hyperparathyroidism, sarcocidosis)
- medullary sponge kidney
- renal tubular acidosis (distal, type 1)
- furosemide therapy in a child
cortical nephrocalcinosis causes
acute cortical necrosis
chronic glomerulonephritis
chronic transplant rejection
hyperoxaluria
Alport syndrome
most common uretral neoplasm
transitional cell carcinoma
fibroepithelial polyp
most common benign tumor of the ureter
typically proximally
