USMLE Practice 2021


B – She has Cushing’s syndrome with classic red/purple abdominal striae (aka “stretch marks”), truncal obesity, and moon facies. Increased levels of the stress hormone cortisol often result in hypertension, and muscle wasting is common in this runaway catabolic process resulting in weakness.

C – Osgood-Schlatter is also known as apophysitis of the tibial tubercle. It’s due to chronic stress/irritation at the insertion of the patellar tendon on the tibial tubercle. It’s classically seen in teenagers doing repetitive vigorous activity (running, jumping). The radiograph demonstrates classic fragmentation of the tibial tubercle (which isn’t necessary to recognize to get the question correct).

D – Radon is a radioactive gas and common ground contaminant. Given off by soil, it’s heavy and is thus typically concentrated in basements. That said, this question is garbage: wood dust is also a known carcinogen.

A – Fear = amygdala

E – Cystic fibrosis is an autosomal recessive disease involving CFTR, which means you need a double hit to express the disease. If the genetic test only picked up one, then it must have missed the other.

E – What terrible machine learning algorithm wrote these other answer choices?

E – If you ever had a child or spent time with someone who has, you would know this is stone-cold normal. Remember, if normal is an answer choice, the default answer is to pick it unless really convinced otherwise.

A – Early-onset tremor with presumed autosomal dominant inheritance (and successively earlier ages of onset aka “anticipation”) with associated psychiatric disturbances and likely early death is concerning for Huntington’s disease. Involvement is centered in the basal ganglia, particularly the caudate. Resting tremor is most commonly Parkinson’s. Intention tremors (resulting in zig-zagging as the patient tries to hone in on the target) and dysmetria (i.e. over/under reaching) are most commonly a result of a cerebellar process such as a stroke.