Systemic Pathology — MCQs

A 4-year-old boy is brought to the emergency department with 2 days of fever and painful lumps in his legs bilaterally. In addition, he says that his arms and legs are extremely itchy. Since birth he has had recurrent skin and soft tissue infections. Physical exam reveals a pruritic erythematous scaling rash along both upper and lower extremities bilaterally. Palpation of the painful lesions reveal indurated tissue without any production of pus. Which of the following protein functions is most likely disrupted in this patient?

A previously healthy 59-year-old man comes to the physician with a 6-month history of worsening headaches, difficulty chewing, and progressive hearing loss. Examination shows a mildly tender, 1-cm, hard swelling over the left maxilla. The remainder of the examination shows no abnormalities. Serum studies show a calcium concentration of 8.5 mg/dL, alkaline phosphatase activity of 112 U/L, and parathyroid hormone concentration of 310 pg/mL. Audiometry shows bilateral mixed conductive and sensorineural hearing loss. Which of the following processes is the most likely cause of this patient's condition?

An 11-month-old male is brought to the emergency room by his mother. The mother reports that the child is in severe pain and has not moved his right leg since earlier this morning when he was crawling on the floor. The child did not fall or sustain any obvious injury. The child’s past medical history is notable for anemia and recurrent infections since birth. His temperature is 99.1°F (37.3°C), blood pressure is 100/65 mmHg, pulse is 120/min, and respirations are 22/min. Physical examination reveals mild macrocephaly and hepatosplenomegaly. Palpation of the right femur seems to exacerbate the child’s pain. A radiograph demonstrates a transverse mid-shaft femur fracture. Which of the following is the most likely cause of this patient’s condition?

A 20-year-old man comes to the clinic complaining of fever and a sore throat for 5 days. He receives oral penicillin from his primary doctor. After a day of antibiotic treatment, he developed gross hematuria. As a child, he recalls having multiple episodes of hematuria. The vital signs are within normal limits. On physical examination, pharyngeal edema and cervical lymphadenopathy are present. His laboratory examination reveals the following: WBC 11,000/mm3 Neutrophils 76% Lymphocytes 23% Eosinophils 1% Platelets 150,000/mm3 Hemoglobin 14 g/dL Hct 41.2% BUN 16 mg/dL Creatinine 0.9 mg/dL ASO titer 100 Urinalysis shows hematuria but no proteinuria. Immunofluorescence shows granular IgA immune complex deposits in the mesangium. Hepatitis B, hepatitis C, and HIV serology are negative. ASO titers and C3 levels are within normal limits. What is the most likely diagnosis?

A 31-year-old man presents to his primary care physician with shortness of breath. He states that he had a “cold” 2 weeks ago and since then has had a persistent cough and worsening shortness of breath. He denies fever, chills, chest pain, sore throat, or rhinorrhea. His medical history is significant for seasonal allergies. He uses fluticasone nasal spray. He had his tonsils removed when he was 8 years of age. His mother and maternal grandfather have cirrhosis, and his father has depression and hypertension. The patient endorses that he smokes tobacco socially on the weekends and uses marijuana daily. He drinks 1-2 beers after work with his co-workers most evenings. A chest radiograph shows hyperinflation of the lungs and hyperlucency. Routine labs are drawn, as shown below. Serum: Na+: 139 mEq/L Cl-: 105 mEq/L K+: 4.0 mEq/L HCO3-: 26 mEq/L Urea nitrogen: 15 mg/dL Glucose: 100 mg/dL Creatinine: 0.8 mg/dL Alkaline phosphatase: 98 U/L Aspartate aminotransferase (AST, GOT): 46 U/L Alanine aminotransferase (ALT, GPT): 49 U/L Pulmonary function tests are pending. Which of the following is most likely to confirm the patient’s diagnosis?

A previously healthy, 16-year-old boy is brought to the emergency department with persistent bleeding from his gums after an elective removal of an impacted tooth. Multiple gauze packs were applied with minimal effect. He has a history of easy bruising. His family history is unremarkable except for a maternal uncle who had a history of easy bruising and joint swelling. Laboratory studies show: Hematocrit 36% Platelet count 170,000/mm3 Prothrombin time 13 sec Partial thromboplastin time 65 sec Bleeding time 5 min Peripheral blood smear shows normal-sized platelets. Which of the following is the most likely diagnosis?

A 6-year-old boy is brought to the pediatrician by his mother after he reported having red urine. He has never experienced this before and did not eat anything unusual before the episode. His past medical history is notable for sensorineural deafness requiring hearing aids. He is otherwise healthy and enjoys being in the 1st grade. His birth history was unremarkable. His temperature is 98.8°F (37.1°C), blood pressure is 145/85 mmHg, pulse is 86/min, and respirations are 18/min. On examination, he is a well-appearing boy in no acute distress. Cardiac, respiratory, and abdominal exams are normal. A urinalysis is notable for microscopic hematuria and mild proteinuria. This patient’s condition is most commonly caused by which of the following inheritance patterns?

A 7-year-old girl presents with fatigue, jaundice, pruritus, and frequent pale stools. She developed these symptoms gradually over the past 3 months. Her past medical history is significant for multiple episodes of bronchitis and pneumonia. When asked about current respiratory symptoms, she says that she sometimes feels short of breath and has a dry, non-productive cough. Her mother was diagnosed with chronic obstructive pulmonary disease at age of 27. The girl's blood pressure is 110/80 mm Hg, the heart rate is 107/min, the respiratory rate is 18/min, and the temperature is 36.9°C (98.4°F). On physical examination, the patient is jaundiced with several petechiae over the inner surface of her upper and lower extremities. On auscultation, lung sounds are diminished and occasional wheezes are heard over the lower pulmonary lobes bilaterally. Heart auscultation reveals muffled heart sounds and no murmurs. On palpation, there is tenderness in the right upper quadrant of the abdomen and hepatomegaly. Her chest X-ray shows bilateral lower lobe emphysema. Which microscopic pathological changes are most characteristic of the patient’s condition?

A 21-year-old man comes to the emergency department because of a 2-week history of progressive shortness of breath and intermittent cough with blood-tinged sputum. During this time, he has also noticed blood in his urine. He has no history of serious illness and does not take any medications. His temperature is 37°C (98.6°F), pulse is 92/min, respirations are 28/min, and blood pressure is 152/90 mm Hg. Cardiopulmonary examination shows crackles at both lung bases. Urinalysis is positive for blood and results of a direct enzyme-linked immunoassay are positive for anti-GBM antibodies. The pathogenesis of this patient's disease is most similar to which of the following?

A 56-year-old man presents with feelings of anxiety and fatigue for the past 4 months. He says that he has also had some weight loss, as well as occasional double vision and a gritty sensation in his eyes for the last 2 months, which is worse at the end of the day. He has also noticed some painless swelling in his fingers and lower legs during the same time period. The patient denies any recent history of fevers, chills, night sweats, nausea, or vomiting. Current medications include aspirin, simvastatin, and omeprazole. Which of the following mechanisms is most likely responsible for this patient’s condition?