United State Medical Licensing Examination (Step 1) Set 20

A 64-year-old man with long-standing hypertension experiences severe abdominal pain and loses consciousness. He dies en route to the hospital. Significant autopsy findings include dilation of the aorta just above the iliac bifurcation and massive abdominal hemorrhage. Which of the following was most likely the initiating event that resulted in his fatal lesion?

A 5-year-old boy is brought to a pediatrician by his mother for progressive abdominal girth and poor appetite. His mother is concerned over a "growing lump" she has felt in his abdomen, and physical examination confirms the presence of a large palpable mass in the left upper quadrant. Abdominal ultrasound demonstrates an 18-cm solid mass in the upper pole of the left kidney. Arenal biopsy is taken. Which of the following is the pathologist most likely to see on microscopic examination of the biopsy?

Over the past few months, a 5-year-old boy has developed changes suggestive of puberty. Physical examination reveals the presence of secondary sex characteristics including pubic hair and penile enlargement. Laboratory studies reveal increased levels of ACTH. If you were able to examine his adrenals, which of the following would you most likely find?

A 7-year-old girl presents with a neck mass located at the anterolateral aspect of the neck, anterior to the sternocleidomastoid muscle. A biopsy of the lesion revealed a largely cystic mass lined by stratified squamous epithelium surrounded by an underlying dense layer of lymphoid tissue with germinal centers. Based on these findings, what is the most likely diagnosis?

A 45-year-old man developed severe abdominal pain and was transported to the emergency room where he was found to be hypotensive and in shock. He was unresponsive to therapy and died 2 days later. Based upon this history and the accompanying image in below figure, which of the following most likely initiated this sequence of events?

Approximately 6 months ago, a 59-year-old man developed a dull, continuous abdominal pain that radiated to the right upper quadrant and was relieved by bending forward. He has also had recurrent thrombophlebitis. He now develops jaundice. Of the following, which is the condition that would most likely explain all of these findings?

A 67-year-old man complains of low back pain and generalized weakness, gradually worsening over the past 6 months. Physical examination reveals an individual in moderate discomfort due to the back pain. Laboratory examination reveals an anemia with rouleaux formation of the erythrocytes on the peripheral smear. Urinalysis demonstrates proteinuria and hypercalciuria. X-rays reveal diffuse osteoporosis of the spine and small lytic lesions in the ribs. Which of the following diagnoses most likely explains these findings?

A 67-year-old woman complains of gradually increasing fatigue. On physical examination, she is found to be anemic and has a peripheral neuropathy characterized by loss of position and vibratory sense. Laboratory studies document a macrocytic anemia and decreased WBC and platelets counts. What pathological mechanism accounts for these findings?

A 27-year-old woman complains of double vision and drooping of her eyelids. She also states that she has recently noticed weakening of her jaws when chewing tough foods. Physical examination reveals mild weakness of her facial and neck muscles but no atrophy is noted. Which of the following diagnoses is most likely?

During a routine dental examination of a 55-year-old man, a small, reddish, and raised lesion is noted on the posterior of the median sulcus of his tongue. The patient is referred to a surgeon who performs an excisional biopsy of the lesion. A section of the biopsy is shown in below figure. Which of the following is the most appropriate diagnosis?