USMLE-Rx Step 2 Practice Q's

USMLE-Rx Step 2 Qmax Challenge #21599

Check out today’s Step 2 CK Qmax Question Challenge.

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USMLE-Rx Step 2 Qmax Challenge #21599A 55-year-old white man presents to the emergency department complaining of diffuse, constant bone pain for the past 3 months. He is a schoolteacher. He denies any recent history of trauma or infection. He does note that his favorite fitted baseball hat no longer fits. His temperature is 37.6°C (99.7°F), blood pressure is 120/75 mm Hg, pulse is 85/min, and respiratory rate is 22/min. Physical examination reveals no focal points of tenderness. Mild frontal bossing and bilateral tibial bowing are noted. X-ray of the pelvis is shown in the image.

Which of the following is the most likely diagnosis?

A. Ankylosing spondylitis
B. Paget’s disease
C. Pituitary adenoma
D. Rickets
E. Scurvy


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6 replies »

  1. B pagets disease. X ray shows bone remodeling with lytic lesions and also cortical thickening of sacral vertebrae and trabecular coarsening. Also note the dense sclerosis of the bone.


  2. The correct answer is B. Paget’s disease is characterized by an increased rate of bone turnover, causing both excessive resorption as well as excessive formation. The history of diffuse bone pain and increasing head size in conjunction with the physical examination findings of frontal bossing and tibial bowing are suspicious for Paget’s disease. This x-ray demonstrates the classic enlarged, dysmorphic, and sclerotic appearance of the pelvis in patients with Paget’s disease. Additionally, these patients will have an elevated alkaline phosphatase with normal calcium and phosphate. A majority of those with Paget’s disease are asymptomatic and do not require treatment. Treatment may be indicated in order to treat symptoms or to prevent complications. Treatment includes calcitonin and bisphosphonates to slow bone resorption.

    A is not correct. This disorder is associated with ankylosis/fusion of joints, and does not fit well with the description and findings in this case. Ankylosing spondylitis typically presents in the late teens and early 20s with hip pain and lower back pain that is worst in the morning and improves with activity. Radiographic findings include bilateral sacroiliac changes such as blurry erosions or hardening/thickening of the fibrous tissue around the sacroiliac joints. Spinal x-rays show “bamboo spine” from ossification of the annulus fibrosus, anterior longitudinal ligament, and bony bridges across the intervertebral spaces.

    C is not correct. Hormone imbalances associated with pituitary adenomas may manifest in a number of ways including acromegalic bony changes. Radiographic findings include calvarial thickening of the skull and enlarged sinuses. X-rays of the hands show a spade appearance of the terminal phalangeal tufts due to hypertrophy. However, the history and findings (including the bilateral bowing of the tibias) are most consistent with Paget’s disease.

    D is not correct. Rickets, or osteomalacia, is the weakening and softening of bones that is frequently associated with decreased vitamin D or calcium intake. X-ray findings include bowing of the femurs (genu varum) and a deformed chest. Changes in the skull can also lead to a square-headed appearance. Although it can occur in adults, it occurs most frequently in early childhood. This is particularly common in developing countries as a result of famine and malnourishment.

    E is not correct. Scurvy is a disorder of collagen synthesis typically associated with vitamin C deficiency. Common manifestations of scurvy include perifollicular hemorrhages, perifollicular hyperkeratotic papules, petechiae and purpura, splinter hemorrhages, bleeding gums, hemarthroses, and subperiosteal hem


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