WBR0674
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| Author | [[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Serge Korjian)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Gastrointestinal, SubCategory::Genitourinary, SubCategory::General Principles |
| Prompt | [[Prompt::A 69-year-old woman with a past medical history significant for coronary artery disease, peripheral vascular disease, heart failure, and atrial fibrillation presents to the emergency department for severe abdominal pain that started several minutes before admission. Physical examination is grossly unremarkable. The abdomen is nontender and no masses or hepatosplenomegaly could be appreciated. The patient undergoes CT angiography and the diagnosis of occlusive acute mesenteric ischemia of the superior mesenteric artery (SMA) is made. Urgent laparotomy shows significant small bowel infarcts. Which of the following organs most likely has a similar gross pathological appearance when infarcted?]] |
| Answer A | AnswerA::Testis |
| Answer A Explanation | AnswerAExp::Testes and ovaries undergo red (hemorrhagic) infarction. |
| Answer B | AnswerB::Heart |
| Answer B Explanation | AnswerBExp::Heart, kidney, and spleen undergo white (pale or anemic) infarction. |
| Answer C | AnswerC::Kidney medulla |
| Answer C Explanation | AnswerCExp::Heart, kidney, and spleen undergo white (pale or anemic) infarction. |
| Answer D | AnswerD::Spleen |
| Answer D Explanation | AnswerDExp::Heart, kidney, and spleen undergo white (pale or anemic) infarction. |
| Answer E | AnswerE::Kidney cortex |
| Answer E Explanation | AnswerEExp::Heart, kidney, and spleen undergo white (pale or anemic) infarction. |
| Right Answer | RightAnswer::A |
| Explanation | [[Explanation::The patient in this scenario has mesenteric ischemia that most likely progressed to mesenteric infarction. Acute mesenteric ischemia is considered a medical emergency. Patients are classically older than 60 years of age with a prominent cardiovascular past medical history, such as heart failure, myocardial infarction, and arrhythmias that predispose them to arterial embolization to the mesenteric arteries. Physical examination in early mesenteric ischemia is usually unremarkable and interestingly contradicts the patient's symptoms. The patients typically complain of excruciating pain but little or no tenderness can be appreciated on physical examination. CT angiography is currently the gold standard for the diagnosis of acute mesenteric ischemia. Laparotomy is especially indicated when peritoneal symptoms are present and when infarction is suspected.
Bowel ischemia is called red (hemorrhagic) ischemia, similar to that seen in loose tissues that contain dual circulations such as the lungs, and small intestine, in venous occlusion such as that seen in ovarian and testicular torsions, and in loose tissues such as the lung. On the other hand, white (pale or anemic) ischemia is characteristic of solid organs that contain end arterial circulation such as the heart, kidney, and spleen. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Infarct, WBRKeyword::Red infarction, WBRKeyword::White infarction, WBRKeyword::Hemorrhagic, WBRKeyword::Mesenteric ischemia, WBRKeyword::Superior mesenteric artery |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |