Systemic Pathology — MCQs

A 54-year-old man comes to the physician because of a cough with blood-tinged sputum for 1 week. He also reports fever and a 5-kg (11 lb) weight loss during the past 2 months. Over the past year, he has had 4 episodes of sinusitis. Physical examination shows palpable nonblanching skin lesions over the hands and feet. Examination of the nasal cavity shows ulceration of the nasopharyngeal mucosa and a depressed nasal bridge. Oral examination shows a painful erythematous gingival enlargement that bleeds easily on contact. Which of the following is the most likely cause of the patient's symptoms?

A 3-year-old boy is brought to the physician by his parents for a well-child examination. The boy was born at term via vaginal delivery and has been healthy except for impaired vision due to severe short-sightedness. He is at the 97th percentile for height and 25th percentile for weight. Oral examination shows a high-arched palate. He has abnormally long, slender fingers and toes, and his finger joints are hyperflexible. The patient is asked to place his thumbs in the palms of the same hand and then clench to form a fist. The thumbs are noted to protrude beyond the ulnar border of the hand. Slit lamp examination shows lens subluxation in the superotemporal direction bilaterally. Which of the following is the most likely underlying cause of this patient's condition?

A 20-month-old boy is brought to the emergency department by his parents with fever and diarrhea that have persisted for the past 2 days. He has a history of repeated bouts of diarrhea, upper respiratory tract infections, and failure to thrive. His vital signs are as follows: blood pressure 80/40 mm Hg, pulse 130/min, temperature 39.0°C (102.2°F), and respiratory rate 30/min. Blood tests are suggestive of lymphopenia. The child is diagnosed with severe combined immune deficiency after additional testing. Which of the following is the most common association with this type of immunodeficiency?

A 49-year-old woman is brought to the emergency department by her daughter because of increasing arthralgia, headache, and somnolence for the past week. She has a history of systemic lupus erythematosus without vital organ involvement. She last received low-dose glucocorticoids 2 months ago. Her temperature is 38.6 °C (101.5 °F), pulse is 80/min, respirations are 21/min, and blood pressure is 129/80 mm Hg. She is confused and disoriented. Examination shows scleral icterus and ecchymoses over the trunk and legs. Neurological examination is otherwise within normal limits. Laboratory studies show: Hemoglobin 8.7 g/dL Leukocyte count 6,200/mm3 Platelet count 25,000/mm3 Prothrombin time 15 seconds Partial thromboplastin time 39 seconds Fibrin split products negative Serum Bilirubin Total 4.9 mg/dL Direct 0.5 mg/dL A blood smear shows numerous fragmented red blood cells. Urinalysis shows hematuria and proteinuria. Which of the following is the most likely diagnosis?

An investigator studying disorders of hemostasis performs gene expression profiling in a family with a specific type of bleeding disorder. These patients were found to have abnormally large von Willebrand factor (vWF) multimers in their blood. Genetic analysis shows that the underlying cause is a mutation in the ADAMTS13 gene. This mutation results in a deficiency of the encoded metalloprotease, which is responsible for cleavage of vWF. Which of the following additional laboratory findings is most likely in these patients?

A 32-year-old man presents with a 2-month history of increasing lethargy, frequent upper respiratory tract infections, and easy bruising. Past medical history is unremarkable. The patient reports a 14-pack-year smoking history and says he drinks alcohol socially. No significant family history. His vital signs include: temperature 36.8°C (98.2°F), blood pressure 132/91 mm Hg and pulse 95/min. Physical examination reveals conjunctival pallor and scattered ecchymoses on the lower extremities. Laboratory results are significant for the following: Hemoglobin 8.2 g/dL Leukocyte count 2,200/mm3 Platelet count 88,000/mm3 Reticulocyte count 0.5% A bone marrow biopsy is performed, which demonstrates hypocellularity with no abnormal cell population. Which of the following is the most likely diagnosis in this patient?

Four days after admission to the hospital for acute pancreatitis, a 41-year-old man develops hypotension and fever. His temperature is 39.1°C (102.3°F), pulse is 115/min, and blood pressure is 80/60 mm Hg. Physical examination shows warm extremities, asymmetric calf size, and blood oozing around his IV sites. There are numerous small, red, non-blanching macules and patches covering the extremities, as well as several large ecchymoses. His hemoglobin concentration is 9.0 g/dL. A peripheral blood smear shows schistocytes and decreased platelets. Which of the following sets of serum findings are most likely in this patient? $$$ Prothrombin time %%% Partial thromboplastin time %%% Fibrinogen %%% D-dimer $$$

A 12-year-old boy is brought by his parents to the physician for a fever for the past 2 days. His temperature is 101.3°F (38.5°C). His medical history is significant for sickle cell disease and recurrent infections. A year ago, he underwent spleen scintigraphy with technetium-99m that revealed functional hyposplenism. Which of the following findings would be found in a peripheral blood smear from this patient?

A previously healthy 15-year-old girl is brought to the physician by her parents for lethargy, increased thirst, and urinary frequency for 10 days. She is 173 cm (5 ft 8 in) tall and weighs 54 kg (120 lb); BMI is 18 kg/m2. Physical examination shows no abnormalities. Her serum glucose concentration is 224 mg/dL. A urine dipstick is positive for ketone bodies. Which of the following is most likely involved in the pathogenesis of this patient's condition?

A 30-year-old woman comes to the emergency department because of weakness and fatigue for 2 days. She has also noticed that her urine is darker than usual. For the past week, she has had a persistent non-productive cough and low-grade fever. She has seasonal allergies. She drinks one to two glasses of wine on social occasions and does not smoke. Her temperature is 37.9°C (100.2°F), pulse is 88/min, respirations are 18/min, and blood pressure is 110/76 mm Hg. She has conjunctival pallor and scleral icterus. Cardiopulmonary examination shows bibasilar crackles. The remainder of the physical examination shows no abnormalities. Laboratory studies show: Leukocyte count 8,000/mm3 Hemoglobin 7.1 g/dL Hematocrit 21% Platelet count 110,000/mm3 MCV 94 μm3 Serum Total bilirubin 4.3 mg/dL Direct 1.1 mg/dL Indirect 3.2 mg/dL AST 15 U/L ALT 17 U/L LDH 1,251 U/L Haptoglobin 5.8 mg/dL (N = 41–165) An x-ray of the chest shows bilateral patchy infiltrates. A peripheral blood smear shows spherocytes. Which of the following is most likely to confirm the diagnosis?