MCQ Book Questions

Q60842. A 9-year-old boy is evaluated for signs of precocious puberty. Laboratory tests demonstrate a 21-hydroxylase defi ciency and increased serum levels of androgens. A CT scan reveals enlargement of the adrenal glands bilaterally. If this patient is untreated, short stature will result as a consequence of which of the following mechanisms of disease?

Q60843. A 17-year-old girl suffers a spiral fracture of her right tibia, and the leg is casted. Unfortunately, the fracture does not heal cor- rectly due to excessive motion and interposition of soft tissue at the fracture site. Which of the following represents the most likely complication of nonunion in this patient?

Q60844. A 50-year-old woman presents with lower back pain of 3 weeks in duration. Radiologic studies reveal several dis- crete lytic lesions in the lumbar back and pelvis. Laboratory studies show elevated serum levels of alkaline phosphatase. Serum calcium, serum protein, and peripheral blood smears are normal. Aspiration biopsy of a pelvic lesion shows keratin- positive cells. Which of the following is the most likely diagnosis?

Q60845. A 6-year-old child with mild hydrocephalus suffers chronic infections and dies of intractable chronic anemia. At autopsy, his bones are dense and misshapen. The femur, in particular, shows obliteration of the marrow space. Histologically, the bones dem- onstrate disorganization of bony trabeculae by retention of pri- mary spongiosa and further obliteration of the marrow spaces by secondary spongiosa (shown in the image). Hematopoietic bone marrow cells are sparse. The disorder is caused by muta- tions in genes that regulate which of the following cell types?

Q60846. A 10-year-old boy complains of increasing pain in his left hip. He began limping shortly after playing a baseball game at school. He is afebrile. An X-ray of the femoral head shows a fracture and irregular densities of the cancellous bone. You make a diagnosis of Legg-Calvé-Perthes disease. Which of the following best describes the pathologic fi ndings in this patient?

Q60847. A 50-year-old man presents with a 2-day history of left leg pain. His temperature is 38.7°C (103°F). He has a harsh systolic murmur and echocardiographic evidence of bacterial endocarditis. If this patient has developed hematogenous osteomyelitis, his bone infection would most likely be found in which of the following anatomic locations?

Q60848. A 74-year-old, obese woman (BMI = 33 kg/m2) complains of chronic pain in her back, knees, and fi ngers. The pain typi- cally subsides at rest. On physical examination, the distal interphalangeal joints are enlarged and tender. Which of the following best describes the pathogenesis of joint pain in this patient?

Q60849. A 60-year-old woman with arthritis suffers a massive stroke and expires. At autopsy, the proximal phalangeal joint tis- sue shows pannus, synovial cell hyperplasia, and lymphoid follicles. Which of the following best describes the pathogen- esis of pannus formation in this patient?

Q60850. A 33-year-old woman presents with a spontaneous fracture of her femoral head. She has suffered from Crohn disease for 20 years. Multiple surgical procedures have resulted in the removal of much of her small bowel. She has had profound weight loss over the last 10 years. The bone is pinned. Histo- logically, the resected femoral head shows bony trabeculae that are covered by a thicker-than-normal layer of osteoid (shown in the image). In this section, the osteoid is stained red, and mineralized bone is stained black. Which of the following best describes the pathogenesis of this lesion?

Q60851. A 67-year-old man from England develops bow-legs and leg pain over a period of 5 years. He also complains of progres- sive hearing loss over the last 2 years. A bone biopsy shows a mosaic pattern with prominent cement lines and increased osteoblastic and osteoclastic activity. Serum electrolyte levels are normal. This patient is at increased risk for developing which of the following diseases?

Q60852. A 60-year-old man with a history of gout presents with mul- tiple rubbery nodules on his hands (shown in the image). Which of the following best explains the pathogenesis of this patient’s underlying condition?

Q60853. A 23-year-old man complains of stiffness and pain in his lower back that causes him to awaken at night. He fi rst noticed morning stiffness in his lower back during his college years. He also describes occasional pain in his right eye and sensitiv- ity to light. An X-ray of the sacroiliac region shows fusion of the small joint spaces in the posterior spine and ossifi cation of the intervertebral discs. Serologic tests for rheumatoid fac- tor and antinuclear antibodies are negative. This patient most likely expresses which of the following human leukocyte anti- gen (HLA) haplotypes?

Q60854. A 9-year-old boy complains of 2 weeks of pain in the hip. His temperature is 38°C (101°F). Laboratory studies show an elevated erythrocyte sedimentation rate. An X-ray reveals a mottled radiolucent defect in the upper femur, with abun- dant periosteal new bone formation. Fine-needle aspiration returns numerous neutrophils and cocci. Staphylococcus aureus is cultured from the bone lesion. A biopsy shows a fragment of necrotic bone embedded in fi brinopurulent exudate. Which of the following terms best describes the necrotic bone?

Q60855. A 40-year-old woman complains of morning stiffness in her hands. On physical examination, her fi nger joints are painful, swollen, and warm. X-ray examination of the hands shows narrowing of the joint spaces and erosion of joint surfaces of the metacarpal/phalangeal joints. The adjacent bones show osteoporosis. A synovial biopsy reveals prominent lymphoid follicles, synovial hyperplasia, and villous folds (shown in the image). Laboratory studies conducted on a blood sample from this patient will most likely show polyclonal antibodies directed against which of the following proteins?

Q60856. A 55-year-old man presents with pain in the left arm. Labo- ratory studies show elevated serum levels of calcium and parathyroid hormone. An X-ray of the left arm reveals mul- tiple small bone cysts and pathologic fractures. Biopsy of the affected bone discloses numerous giant cells in a cellu- lar and fi brous stroma. The patient undergoes removal of a parathyroid adenoma. Which of the following best describes the pathogenesis of bone pain and pathologic fractures in this patient?

Q60857. A 2-year-old boy presents with a rash. On physical examina- tion, he has a crusty, red skin lesion at the hairline and on the extensor surfaces of his extremities and abdomen. Exophthal- mos is noted. An X-ray fi lm of the head shows multiple, radio- lucent lesions in the skull. A biopsy of one of the skull lesions shows large, plump cells with pale, eosinophilic, foamy cyto- plasm and convoluted nuclei (shown in the image). What is the most likely diagnosis?

Q60858. A 28-year-old man complains of burning pain on urination, as well as pain in his fi ngers and left eye. He also relates a recent episode of bacillary diarrhea contracted during a visit to Mexico. Physical examination confi rms arthritis and conjunctivitis. The patient responds well to treatment with NSAIDs. Which of the following is the most likely diagnosis?

Q60859. An 85-year-old man presents with a 3-week history of pain- ful swelling of his right knee. Aspiration of joint fl uid returns numerous neutrophils and crystals, which are described as rhomboid and “coffi n-like.” Chemical analysis shows that these crystals are composed of calcium pyrophosphate. Which of the following is the most likely diagnosis?

Q60860. A 10-year-old boy complains of pain in his hands and feet. His temperature is 38°C (101°F). Physical examination reveals a faint pericardial friction rub. His spleen, liver, and axillary lymph nodes are enlarged. Which of the following is the most likely diagnosis?

Q60861. A 58-year-old woman fractures her hip after slipping on an icy sidewalk. An X-ray shows generalized osteopenia. A bone biopsy reveals attenuated bony trabeculae and a normal ratio of mineral-to-matrix. Serum calcium and phosphorus levels are normal. Which of the following best explains the pathogenesis of osteopenia in this postmeno- pausal woman?