WBR0415

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Renal
Prompt	[[Prompt::A 52-year-old man with an unknown past medical history dies following a motor vehicle collision. On autopsy, his kidneys have the following appearance as shown in the image below. Which of the following clinical findings is mostly associated with this patient's condition? File:WBR0415.jpg.jpg]]
Answer A	AnswerA::Large hepatic multiacinar regenerative nodules
Answer A Explanation	[[AnswerAExp::Large hepatic multiacinar regenerative nodules are characteristic of hepatic fibrosis. Congenital hepatic fibrosis is common among patients with autosomal recessive polycystic kidney disease (ARPKD), which manifests early in childhood. On the other hand, ADKPD is associated]]
Answer B	AnswerB::Granulomatous inflammation and skip lesions in a bowel segment
Answer B Explanation	AnswerBExp::Granulomatous inflammation and skip lesions are characteristic of Crohn’s disease. ADPKD is not classically associated with Crohn’s disease.
Answer C	AnswerC::Cranial nerve compression by an adjacent structure
Answer C Explanation	[[AnswerCExp::Autosomal (adult) dominant polycystic kidney disease (ADPKD) is an inherited renal disorder characterized by the development of fluid-filled cysts in both kidneys during adulthood. It is associated with the development of berry aneurysms, which may cause mechanical compression of the nearby CN III in case of posterior communicating artery aneurysm. As a result, patients often present with “blown pupils” with absent papillary light reflex.]]
Answer D	AnswerD::Granulomatous inflammation of a great vessel
Answer D Explanation	AnswerDExp::Granulomatous inflammation of the aorta is a characteristic feature of Takayasu vasculitis (pulseless disease).
Answer E	AnswerE::Obliteration of the biliary tree
Answer E Explanation	AnswerEExp::Obliteration of the biliary tree is characteristic of sclerosing cholangitis. Sclerosing cholangitis is classically associated with ulcerative colitis, not ADPKD.
Right Answer	RightAnswer::C
Explanation	[[Explanation::Autosomal (adult) dominant polycystic kidney disease (ADPKD) is an inherited renal disease characterized by fluid-filled cystic enlargement in both kidneys during adulthood that progressively leads to renal failure. ADPKD is associated with berry aneurysms and development of multiple hepatic, pancreatic, and intestinal/colonic cysts. Berry aneurysms are caused by weakness of the cerebral artery walls, which results in dilation of the affected artery. Aneurysm formation in the posterior communicating artery may lead to compression of CN III (oculomotor cranial nerve). CN III contains an inner central motor component and an outer peripheral parasympathetic component. Hence, different diseases may affect CN III differently. Mechanical compression of CN III affects the outer parasympathetic component and leads to “blown pupils” with absent papillary light reflex. On the other hand, vascular diseases, such as long-standing diabetes mellitus, cause ischemic injury to the inner motor component, and patients present with a “down and out” gaze when the inner motor component is affected. Educational Objective: Autosomal (adult) dominant polycystic kidney disease (ADPKD) is an inherited renal disorder characterized by the development fluid-filled cysts in both kidneys during adulthood. ADPKD is associated with berry aneurysms that may affect the posterior communicating artery and result in the mechanical compression of CN III. References: First Aid 2014 page 87]]
Approved	Approved::Yes
Keyword	WBRKeyword::kidney, WBRKeyword::excretory system, WBRKeyword::autosomal dominant, WBRKeyword::genetics, WBRKeyword::pattern of inheritance, WBRKeyword::berry aneurysms, WBRKeyword::CN III, WBRKeyword::artery
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