WBR0674
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| 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 (ED) in excruciating abdominal pain that started several minutes before admission. Physical examination is unremarkable. The abdomen is nontender, no masses or hepatosplenomegaly could be appreciated. The patient undergoes computed tomography (CT) angiography and the diagnosis of occlusive acute mesenteric ischemia of the superior mesenteric artery (SMA) is made. Urgent laparotomy shows infarcts of specific abdominal regions. 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 has mesenteric ischemia that most likely progressed to mesenteric infarction. It is considered an emergency, whereby patients are usually older than 60 years with a prominent cardiovascular past medical history, such as heart failure, myocardial infarction, and arrhythmias that predispose them to arterial embolization to the superior mesenteric arteries. As seen in this patient, physical examination in mesenteric ischemia is usually unremarkable and interestingly contradicts the patient's symptoms. The patients typically complain of excruciating pain but no tenderness on physical examination. CT angiography is currently widely used for the diagnosis of acute mesenteric ischemia. Laparotomy is especially indicated when peritoneal symptoms are present and when infarction is suspected, but it is performed anyways in almost all cases of acute mesenteric ischemia.
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 Educational Objective: Lung, liver, bowels, ovaries, and testes undergo red (hemorrhagic) infarction. |
| Approved | Approved::No |
| Keyword | WBRKeyword::infarct, WBRKeyword::infarction, WBRKeyword::white, WBRKeyword::red, WBRKeyword::pale, WBRKeyword::anemic, WBRKeyword::hemorrhagic, WBRKeyword::mesenteric, WBRKeyword::ischemia, WBRKeyword::laparotomy |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |