American Board of Internal Medicine (ABIM) Certification Practice Exam

For individuals aged 30 to 59, what is the cyst requirement for a diagnosis of ADPKD?

1. One cyst in each kidney

2. Two cysts in each kidney

3. Three cysts in each kidney

4. Four cysts in each kidney

The correct answer is: Two cysts in each kidney

For individuals aged 30 to 59, the requirement for a diagnosis of Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the presence of two cysts in each kidney. This criterion is based on the established diagnostic criteria, which are informed by the age-specific likelihood of developing renal cysts in ADPKD. In young patients, such as those under 30, the threshold for diagnosis is lower because the cysts may not be as prevalent. However, as patients age, the number of cysts typically increases, and two cysts per kidney is considered sufficient for a definitive diagnosis in this age group. Thus, the clinical approach accounts for the higher probability of cyst development with advancing age, and having two cysts in each kidney is consistent with the genetic inheritance pattern of the disease.