Systemic Pathology — MCQs

A 14-year-old girl is brought to the emergency department because of a 3-day history of worsening confusion, high-grade fever, and a productive cough. She has had recurrent respiratory infections and bulky, foul-smelling, oily stools since infancy. She is at the 14th percentile for height and 8th percentile for weight. Despite appropriate care, the patient dies 2 days after admission. Autopsy of the lungs shows bronchial mucus plugging and bronchiectasis. Which of the following is the most likely underlying cause of this patient's condition?

A 64-year-old man presents to his primary care provider after noticing the development of a blistering rash. The patient states that his symptoms began 1 week ago after he noticed a blister develop on the inside of his mouth that eventually ruptured. Over the past several days, he has noticed several more blisters on his torso. The patient denies a fever or any other symptoms. He has a history of high blood pressure, for which he takes hydrochlorothiazide. He is otherwise healthy and denies any recent changes to his medication. Today, the patient’s temperature is 99.0°F (37.2°C), blood pressure is 124/84 mmHg, pulse is 66/min, and respirations are 12/min. On exam, the patient’s mouth is notable for a previously ruptured blister on his left buccal mucosa. On his left flank and anterior abdomen are scattered 10-15-cm bullae that appear flaccid and filled with serous fluid. The lesions are erythematous but there is no surrounding erythema. On manual rubbing of the skin near the lesions, new blisters form within minutes. Which of the following is involved in the pathogenesis of this disease?

A 63-year-old female enrolls in a research study evaluating the use of iron studies to screen for disease in a population of post-menopausal women. Per study protocol, past medical history and other identifying information is unknown. The patient's iron studies return as follows: Serum iron: 200 µg/dL (normal 50–170 µg/dL) TIBC: 220 µg/dL (normal 250–370 µg/dL) Transferrin saturation: 91% (normal 15–50%) Serum ferritin: 180 µg/L (normal 15-150 µg/L) Which of the following is the most likely cause of these findings?

A 42-year-old man presents to his primary care physician complaining of subjective fever, cough, and night sweats. He states that over the past 2 months he has “not felt like myself.” He has lost 12 lbs over this time period. Two weeks ago, he started experiencing night sweats and cough. This morning he decided to take his temperature and reports it was “high.” He has a history of HIV and admits to inconsistently taking his anti-retrovirals. A chest radiograph reveals a cavitary lesion in the left upper lobe. An interferon-gamma release assay is positive, and the patient is started on appropriate antimicrobial therapy. A month later he is seen in clinic for follow-up. Lab work is obtained, as shown below: Leukocyte count: 11,000/mm^3 with normal differential Hemoglobin: 9.2 g/dL Platelet count: 400,000/mm^3 Mean corpuscular volume (MCV): 75 µm^3 Based on these results, a peripheral smear is sent and shows Pappenheimer bodies. Which of the following is the most accurate test for the patient’s diagnosis?

A previously healthy 4-year-old boy is brought to the emergency department because of a 1-day history of pain and swelling of his left knee joint. He has not had any trauma to the knee. His family history is unremarkable except for a bleeding disorder in his maternal uncle. His temperature is 36.9°C (98.4°F). The left knee is erythematous, swollen, and tender; range of motion is limited. No other joints are affected. An x-ray of the knee shows an effusion but no structural abnormalities of the joint. Arthrocentesis is conducted. The synovial fluid is bloody. Further evaluation of this patient is most likely to show which of the following findings?

A 45-year-old man comes to the physician for a 2-day history of headache and breathlessness on exertion. During the same period, he has vomited twice and not passed urine. He also reports pain and stiffness in his fingers that has worsened progressively over the past 2 years. He has no history of serious illness and takes no medications. He does not smoke or drink alcohol. He is in moderate distress. His temperature is 37.2°C (98.9°F), pulse is 88/min, blood pressure is 170/100 mm Hg, and respirations are 24/min. Pulse oximetry on room air shows an oxygen saturation of 91%. Examination reveals pallor, 2+ pretibial edema, and jugular venous distention. The skin on the arms, chest, and upper back is coarse and thickened. Diffuse cutaneous hyperpigmentation and hypopigmented patches with perifollicular hypopigmentation are noted. Contractures are present in the proximal interphalangeal joints of both hands. Diffuse crackles are heard on auscultation of the chest. There is dullness to percussion and decreased breath sounds over both lung bases. S1 and S2 are normal. An S3 gallop is heard at the apex. The remainder of the examination shows no abnormalities. His hemoglobin concentration is 8.1 g/dL, and his serum creatinine is 5.3 mg/dL. Further evaluation of this patient is most likely to show which of the following?

At a routine exam, a 68-year-old woman is discovered to have a serum calcium level of 11.5 mg/dL. Follow-up laboratory tests show a high parathyroid hormone with low phosphorus and mildly elevated alkaline phosphatase. 24-hour urine calcium level is elevated. Review of symptoms includes complaints of fatigue, constipation, and diffuse bone pain for which she takes vitamin D. Past medical history is significant for type 2 diabetes mellitus for 25 years and essential hypertension for 15 years. The patient has a history of kidney stones. Family history is irrelevant. Which of the following radiologic findings is consistent with the patient's condition?

A 42-year-old woman comes to the physician with acute, severe pain in the middle of her lower back. She also complains of constipation and trouble sleeping recently. Menses occur regularly at 28-day intervals. Examination shows localized tenderness to palpation over the lumbar spine. Serum calcium is 14 mg/dL and serum phosphorus is 1.5 mg/dL. An x-ray of the lumbar spine shows a compression fracture of the L4 vertebral body and osteopenia. Which of the following is the most likely underlying cause of this patient's decreased bone mineral density?

A 70-year-old woman is on hospital day 2 in the medical intensive care unit. She was admitted from the emergency department for a 2-day history of shortness of breath and fever. In the emergency department, her temperature is 39.4°C (103.0°F), the pulse is 120/min, the blood pressure is 94/54 mm Hg, the respiratory rate is 36/min, and oxygen saturation was 82% while on 4L of oxygen via a non-rebreather mask. Chest X-ray shows a right lower lobe consolidation. She was intubated, sedated, and started on broad-spectrum antibiotics for sepsis of pulmonary origin and intravenous norepinephrine for blood pressure support. Since then, her clinical condition has been stable, though her vasopressor and oxygen requirements have not improved. Today, her physician is called to the bedside because her nurse noted some slow bleeding from her intravenous line sites and around her urinary catheter. Which of the following most likely represents the results of coagulation studies for this patient?

A 19-year-old man and recent immigrant from Brazil present to the clinic. He has no known past medical, past surgical, or family history. The patient admits to having several regular sexual partners. Today, he complains of a skin rash on his back. He is unclear when it started but became aware when one of his partners pointed it out. A review of systems is otherwise negative. Physical examination reveals numerous hypopigmented skin lesions over his upper back. When questioned, he states that they do not get darker after spending time in the sun. On examination, there is a 5 cm (1.9 in) patch of hypopigmented skin in the center of his back with a fine-scale overlying it. What is the most likely diagnosis?