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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor= {{SSK}} (Reviewed by Serge Korjian)
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
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|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
|SubCategory=Gastrointestinal
|SubCategory=Gastrointestinal
|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
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|MainCategory=Pathophysiology, Physiology
|MainCategory=Pathophysiology, Physiology
|SubCategory=Gastrointestinal
|SubCategory=Gastrointestinal
|Prompt=A 45 year old man admitted to the hospital for work-up of severe painless jaundice and icterus is found to have a massive obstructive pancreatic head mass almost completely closing the bile duct lumen. Which of the following patterns would you expect in this patient?
|Prompt=A 45-year-old man admitted to the hospital for work-up of severe painless jaundice and icterus is found to have a massive obstructive pancreatic head mass almost completely blocking the bile duct lumen. Which of the following patterns would you expect in this patient?




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Considering the patient's presentation, one would expect obstructive type jaundice. Obstructive jaundice is characterized by direct or conjugated hyperbilirubinemia since the conjugation mechanisms are not affected rather the excretion of conjugated bilirubin through bile is inhibited. As conjugated bilirubin builds up it increases in the blood. As it is water soluble (compared to unconjugated bilirubin which is not) it is excreted in large amounts in the urine, giving the urine a darker color. Urine urobilinogen is a product of bile recycling in the intestines. As the obstruction hinders bile release into the intestine, one would expect urine urobilinogen levels to decrease. Similarly, fecal stercobilin is related to bile content of the fecal material, so one would also expect the stercobilin levels to decrease and stool color to become much lighter.
Considering the patient's presentation, one would expect obstructive type jaundice. Obstructive jaundice is characterized by direct or conjugated hyperbilirubinemia as the conjugation mechanisms are not affected.
 
It is rather the excretion of conjugated bilirubin through the bile is inhibited. As conjugated bilirubin builds up it increases in the blood. As it is water soluble (compared to unconjugated bilirubin which is not) it is excreted in large amounts in the urine, giving the urine a darker color. Urine urobilinogen is a product of bile recycling in the intestines. As the obstruction hinders bile release into the intestine, one would expect urine urobilinogen levels to decrease. Similarly, fecal stercobilin is related to bile content of the fecal material, so one would also expect the stercobilin levels to decrease and stool color to become much lighter.
 
Learning objective: Obstructive jaundice is characterized by direct (conjugated) hyperbilirubinemia with increase in urinary bilirubin and decrease in urobilinogen.
 
 
References:
 
Diagnosis of obstructive jaundice. Calif Med. 1970;112(5):44-58.
Le T, Bhushan V. First Aid for the USMLE Step 1 2014. McGraw-Hill Medical; 2014.
|AnswerA=A
|AnswerA=A
|AnswerAExp=This pattern is usually not seen.
|AnswerAExp=This pattern is usually not seen.
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|AnswerE=E
|AnswerE=E
|AnswerEExp=This pattern is typical of hemolytic type jaundice.
|AnswerEExp=This pattern is typical of hemolytic type jaundice.
|EducationalObjectives=Obstructive jaundice is characterized by direct (conjugated) hyperbilirubinemia with increase in urinary bilirubin and decrease in urobilinogen.
|References=Diagnosis of obstructive jaundice. Calif Med. 1970;112(5):44-58.<br>
Le T, Bhushan V. First Aid for the USMLE Step 1 2014. McGraw-Hill Medical; 2014.
|RightAnswer=B
|RightAnswer=B
|WBRKeyword=Obstructive jaundice, Bilirubin,
|WBRKeyword=Obstructive jaundice, Bilirubin, Jaundice, Conjugated bilirubin, Pancreatic cancer,
|Approved=No
|Approved=Yes
}}
}}

Latest revision as of 01:21, 28 October 2020
Author [[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathophysiology, MainCategory::Physiology
Sub Category SubCategory::Gastrointestinal
Prompt [[Prompt::A 45-year-old man admitted to the hospital for work-up of severe painless jaundice and icterus is found to have a massive obstructive pancreatic head mass almost completely blocking the bile duct lumen. Which of the following patterns would you expect in this patient?


]]

Answer A AnswerA::A
Answer A Explanation AnswerAExp::This pattern is usually not seen.
Answer B AnswerB::B
Answer B Explanation AnswerBExp::This pattern is typical of obstructive jaundice.
Answer C AnswerC::C
Answer C Explanation AnswerCExp::This pattern is usually not seen.
Answer D AnswerD::D
Answer D Explanation AnswerDExp::This pattern is usually not seen.
Answer E AnswerE::E
Answer E Explanation AnswerEExp::This pattern is typical of hemolytic type jaundice.
Right Answer RightAnswer::B
Explanation [[Explanation::


Considering the patient's presentation, one would expect obstructive type jaundice. Obstructive jaundice is characterized by direct or conjugated hyperbilirubinemia as the conjugation mechanisms are not affected. It is rather the excretion of conjugated bilirubin through the bile is inhibited. As conjugated bilirubin builds up it increases in the blood. As it is water soluble (compared to unconjugated bilirubin which is not) it is excreted in large amounts in the urine, giving the urine a darker color. Urine urobilinogen is a product of bile recycling in the intestines. As the obstruction hinders bile release into the intestine, one would expect urine urobilinogen levels to decrease. Similarly, fecal stercobilin is related to bile content of the fecal material, so one would also expect the stercobilin levels to decrease and stool color to become much lighter.
Educational Objective: Obstructive jaundice is characterized by direct (conjugated) hyperbilirubinemia with increase in urinary bilirubin and decrease in urobilinogen.
References: Diagnosis of obstructive jaundice. Calif Med. 1970;112(5):44-58.
Le T, Bhushan V. First Aid for the USMLE Step 1 2014. McGraw-Hill Medical; 2014.]]

Approved Approved::Yes
Keyword WBRKeyword::Obstructive jaundice, WBRKeyword::Bilirubin, WBRKeyword::Jaundice, WBRKeyword::Conjugated bilirubin, WBRKeyword::Pancreatic cancer
Linked Question Linked::
Order in Linked Questions LinkedOrder::
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