A 33-year-old man comes to the office due to left flank pain. He has no chronic medical conditions and takes no medications. The patient does not use tobacco, alcohol, or illicit drugs. Ultrasonogram of the left kidney is shown below. The right kidney has similar findings. Compared to the general population, this patient's condition most increases the likelihood of which of the following complications?

Question

A 33-year-old man comes to the office due to left flank pain.  He has no chronic medical conditions and takes no medications.  The patient does not use tobacco, alcohol, or illicit drugs.  Ultrasonogram of the left kidney is shown below.  The right kidney has similar findings.  Compared to the general population, this patient's condition most increases the likelihood of which of the following complications?

Quizplus · Accepted Answer

11ec25c8_d4f0_a488_bc81_e94cbbfe3d60_MD0003_00 This patient with ultrasonography showing numerous renal cysts likely has autosomal dominant polycystic kidney disease (ADPKD). ADPKD is commonly associated with cerebral aneurysms that may rupture and lead to intracranial bleeding; the prevalence of cerebral aneurysm increases with age, reaching approximately 20% in patients with ADPKD by age 60. ADPKD results from a mutation of either the PKD1 or PKD2 genes, which encode for proteins called polycystins. In addition to affecting renal parenchymal structure, it is believed that disruption of polycystins also causes impaired vascular integrity and contributes to the high prevalence of cerebral aneurysm in the setting of ADPKD. Hypertension, a typical complication of ADPKD resulting from localized renal ischemia and increased renin secretion, likely also contributes by facilitating aneurysm progression and rupture. Progressive renal dysfunction eventually takes place in ADPKD, with patients developing end-stage renal disease by age 55-60 on average. (Choice B) ADPKD is associated with nonmalignant cysts in the liver and, less commonly, the pancreas. However, it is not associated with pancreatic cancer. (Choices C and E) Renal cell carcinoma (RCC) increases the risk of venous thromboembolic disease and is also one of the most common causes of humoral hypercalcemia of malignancy (via parathyroid hormone-related peptide secretion). However, RCC typically appears as a single solid or partially cystic renal mass on ultrasonography; numerous foci in the same kidney would be highly unusual. ADPKD is not associated with hypercalcemia and does not significantly increase the risk of pulmonary embolism. (Choice D) Amyloidosis typically affects older patients (eg, age >50) and can lead to restrictive cardiomyopathy. The disease can also affect the kidneys; imaging typically reveals kidney enlargement, but multiple cysts are not expected. Educational objective: Autosomal dominant polycystic kidney disease is commonly associated with cerebral aneurysms that may rupture and lead to intracranial bleeding. This association is likely related to both impaired vascular integrity caused by the underlying PKD gene mutation as well as the hypertension that is typically present with the disease. References: Vascular complications in autosomal dominant polycystic kidney disease. (http://www.ncbi.nlm.nih.gov/pubmed/26260542)

A 33-Year-Old Man Comes to the Office Due to Left