A 29-year-old with 7 weeks of amenorrhea, unilateral pelvic pain, and spotting has β-hCG of 4,200 mIU/mL. Transvaginal ultrasound shows no intrauterine gestational sac. Best interpretation?

A patient reports persistent, excessive worry about work and family for over 6 months, with restlessness and sleep disturbance. This presentation is most consistent with:

A 55-year-old with progressive proximal muscle weakness has violaceous periorbital discoloration and erythematous papules over the MCPs. Which is most likely?

A 19-year-old with a peanut allergy develops hypotension, wheezing, and urticaria within minutes of ingestion. Which mechanism explains this response?

A 66-year-old with slowly progressive hyperthyroid symptoms has a nodular thyroid on exam; there is no ophthalmopathy or pretibial myxedema. Most likely etiology?

A patient avoids leaving the house, fearing inability to escape if panic occurs. This pattern is best described as:

Which lesion best characterizes a primary syphilitic chancre?

A combat veteran reports intrusive nightmares, avoids crowded areas, and is hypervigilant. These features are most consistent with which PTSD diagnostic cluster?

A 75-year-old with a new blowing holosystolic murmur at the apex and orthopnea likely has which valvular consequence of ventricular remodeling?

Why does invasive cervical cancer most commonly arise at the transformation zone?