GI Question

[Newyorkgiants]

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Had this from a question bank:

a 47 -yea old man comes to the physician because of abdominal pain and fatigue for several months. He has notice that his urine is darker than normal. Physical examination shows icteric sclera. The liver is normal size and the edge is smooth. The gallbladder is palpable but not tender. Laboratory tests show elevated total bilirubin, alkaline phosphatase, and gamma-glutamyl transferase. Ca 19-9 is within normal limits. Which of the following is most likely the diagnosis.

A. Acute cholecystitis
B. Amyloidosis
C. Hepatic Cirrhosis
D. Hepatocellular Carcinoma.
E. Pancreatic cancer

The correct answer was E.

Pancreatic cancer would cause obstructive jaundice. That would mean that there would be no urobilin in the urine. Isn't it the urobilin that gives the urine and stool the dark color?

 

[ChessMaster3000]

Had this from a question bank:

a 47 -yea old man comes to the physician because of abdominal pain and fatigue for several months. He has notice that his urine is darker than normal. Physical examination shows icteric sclera. The liver is normal size and the edge is smooth. The gallbladder is palpable but not tender. Laboratory tests show elevated total bilirubin, alkaline phosphatase, and gamma-glutamyl transferase. Ca 19-9 is within normal limits. Which of the following is most likely the diagnosis.

A. Acute cholecystitis
B. Amyloidosis
C. Hepatic Cirrhosis
D. Hepatocellular Carcinoma.
E. Pancreatic cancer

The correct answer was E.

Pancreatic cancer would cause obstructive jaundice. That would mean that there would be no urobilin in the urine. Isn't it the urobilin that gives the urine and stool the dark color?

Urobilin would be low, but I believe other conjugated bilirubin products can cause pigment in urine. Btw, urobilin is conjugated right?

Also I find it interesting that 19-9 was normal, as this is classically elevated. That is definitely a red herring--a tough one also.

 

[acciddropping]

I would think that the head of the pancreas is where the cancer is, since gb is enlarged and have liver syxs - and it's a presentation of an early cancer? I know that Pancreatic cancer does not show syxs unless it's very late. So, reason for why 199 is normal maybe because it's an early pancreatic cancer) -- can someone explain about urobilin stuff with dark stool stuff if you don't mind? thks

 

[NMDO]

Urobilin is what gives stool and urine its normal color. Normally, conjugated bilirubin enters the bowel and is converted to urobilinogen (--> urobilin). In obstructive liver disease, the CB never enters the bowel so therefore it never gets converted to urobilinogen, so urobilinogen is absent in the stool and urine. This causes light stools. In obstructive disease, you will also have excess CB enter the kidney and be excreted in the urine. I don't know the exact mechanism of why this causes your urine to be dark, but Goljan says bilirubin in your urine will cause a dark color (so I guess just know it).

Also, the gall bladder can be palpable in some cases of cholecystitis, but we were taught to almost always associated palpable gall bladder to cancer. That question is tricky, but with the info given I think process of elimination can get you to the right answer. Hope that helps a little bit. RR pathology covers the urobilinogen/conjugated bilirubin stuff in detail for a better explanation.

 

[Newyorkgiants]

I agree with your reasoning. But according to Goljan its the urobilin that is recycled to the kidney that gives the urine its color. If they never mentioned the color of the urine it would make sense why pancreatic carcinoma is correct, but the dark urine part just throws me off.

 

[mcloaf]

I agree with your reasoning. But according to Goljan its the urobilin that is recycled to the kidney that gives the urine its color. If they never mentioned the color of the urine it would make sense why pancreatic carcinoma is correct, but the dark urine part just throws me off.

Urobilin makes pee yellow, not dark. Bilirubin in urine will make it dark/tea/amber colored.

 

[sarah65]

My two cents: I've come across this question, and this scenario in practice. The question is trying to emphasize Courvoisier's Law: A painless enlarged gallbladder with icterus, the cause is less likely to be gallstones.

Let's knock the options out: Acute cholecystitis incorrect due to painless gb. Amyloidosis: Liver is not enlarged. Cirrhosis: Liver is smooth and normal sized. Hepatocellular carcinoma: Rare, and doesn't fit the biochemical profile. Pancreatic cancer: The back pressure of bile on the biliary tract elevated GGT (specific for biliary duct dysfunction), ALT and AST are not elevated (yet).

The fact that CA 19-9 was not elevated is a definite red-herring though, but I suppose it serves us to give greater weight to clinical signs.

The above is probably an oversimplified snapshot, but I've been trying to retrain my brain into thinking this way to solve the questions in the few seconds provided in the exam, so thought I'd share.

 

[ChessMaster3000]

My two cents: I've come across this question, and this scenario in practice. The question is trying to emphasize Courvoisier's Law: A painless enlarged gallbladder with icterus, the cause is less likely to be gallstones.

Let's knock the options out: Acute cholecystitis incorrect due to painless gb. Amyloidosis: Liver is not enlarged. Cirrhosis: Liver is smooth and normal sized. Hepatocellular carcinoma: Rare, and doesn't fit the biochemical profile. Pancreatic cancer: The back pressure of bile on the biliary tract elevated GGT (specific for biliary duct dysfunction), ALT and AST are not elevated (yet).

The fact that CA 19-9 was not elevated is a definite red-herring though, but I suppose it serves us to give greater weight to clinical signs.

The above is probably an oversimplified snapshot, but I've been trying to retrain my brain into thinking this way to solve the questions in the few seconds provided in the exam, so thought I'd share.

well said, Sarah. I think the biggest thing for me is to not get confused between YELLOW and DARK urine. I get that confused all the time. An easy easy to remember that is only conjugated urine can get into the urine anyway, whether or not its in the urobilinogen form. So if (conjugated) urobilinogen can be reuptaken into the circulation and filtered by the kidney, so can ("regular") conjugated bilirubin.