10. Pathology and Oncology MCQs

A 45-year-old man presents with generalized bone pain and proximal muscle weakness. Laboratory evaluation reveals severe hypophosphatemia, hyperphosphaturia, normal serum calcium, and a normal parathyroid hormone level. Imaging identifies a small mesenchymal tumor in his thigh. Which hormone is most likely being overproduced?

A 77-year-old man has had increasing right knee pain for the past 3 months. A radiograph and coronal T1-weighted MRI scan are shown in Figures 19a and 19b. A biopsy specimen is shown in Figure 19c. What is the most likely diagnosis?

An 83-year-old man has a painful mass of the great toe. Radiographs and a biopsy specimen are seen in Figures 22a and 22b. What is the most likely diagnosis?

A 19-year-old man has had intermittent progressive knee pain with ambulation and pain at night following a rodeo accident 4 weeks ago. Figures 4a through 4e show the radiographs, a bone scan, CT scan, and T2-weighted MRI scan. What is the most likely diagnosis?

A 20-year-old basketball player has tenderness and bruising after sustaining a blow to the knee. A radiograph is shown in Figure 15. What is the most likely diagnosis?

A 12-year-old girl presents with a destructive diaphyseal lesion of the femur with a permeative pattern and an 'onion skin' periosteal reaction.

A core needle biopsy is performed, revealing sheets of uniform small, round, blue cells. Immunohistochemistry is strongly positive for CD99. Which of the following chromosomal translocations is most characteristic of this tumor?

A 14-year-old boy presents with knee pain. Radiographs reveal a mixed sclerotic and lytic lesion in the distal femoral metaphysis with a sunburst periosteal reaction and a Codman triangle. A biopsy shows malignant spindle cells producing osteoid. What is the most significant prognostic factor for survival in this patient?

An athletic 55-year-old man reports a painless mass in the anterior aspect of the thigh that appeared 3 weeks ago and has not changed in size. The patient denies any history of trauma. Examination reveals a firm, well-defined nontender mass in the anterior thigh and no inguinal adenopathy or cutaneous changes. Plain radiographs are unremarkable. T1- and T2-weighted MRI scans are shown in Figures 44a and 44b. What is the most likely diagnosis?

What is the most common primary malignant tumor of bone in childhood?

Figures 21a and 21b show the radiograph and CT scan of a 14-year-old patient with thigh pain. The next most appropriate step in management should consist of

Mutations in the retinoblastoma (Rb) gene are strongly associated with the subsequent development of which of the following primary bone tumors?

The characteristic chromosomal translocation t(11;22)(q24;q12) found in the majority of Ewing sarcoma cases results in the fusion of which two genes?

According to the Seddon classification, a peripheral nerve injury characterized by complete disruption of the axon and myelin sheath, but with preservation of the surrounding endoneurial, perineurial, and epineurial connective tissue is termed:

A 10-year-old boy who plays baseball reports acute pain after throwing a softball from the outfield to second base. A radiograph is shown in Figure 26. Management should consist of

A 10-year-old boy presents with knee pain and inability to actively extend his knee after a jumping injury. Radiographs reveal a high-riding patella and a small bony avulsion from the inferior pole of the patella. What is the most appropriate management?

In a patient sustaining multiple injuries, Damage Control Orthopedics (DCO) relies on early temporary stabilization followed by definitive fixation. Which inflammatory marker is thought to peak on day 2-3 and correlates with the "second hit" phenomenon?

An otherwise healthy 16-year-old boy who has had thoracolumbar pain with an increasingly worse deformity for the past 2 years now reports that the pain is worse at night. He responded well to nonsteroidal anti-inflammatory drugs initially, but they have become less effective. He denies any neurologic or constitutional symptoms. Examination is consistent with a mild thoracolumbar scoliosis and is otherwise normal. Laboratory studies show a normal CBC, erythrocyte sedimentation rate, and C-reactive protein. Standing radiographs show a 20 degree left thoracolumbar scoliosis, and he has a Risser stage of 4. A bone scan shows increased uptake at L2; a CT scan through this level is shown in Figure 18. Management should now consist of

A 45-year-old woman with chronic forefoot pain and a positive Mulder's click in the third webspace undergoes surgical excision of the symptomatic lesion after failing conservative management. Histologic examination of the excised specimen is most likely to reveal which of the following?

A 45-year-old woman presents with progressive diffuse bone pain, muscle weakness, and multiple stress fractures. Lab tests reveal severe hypophosphatemia, normal serum calcium, and markedly elevated FGF-23 levels. Which of the following best describes the pathogenesis of her condition?

A 30-year-old male presents with a slow-growing, painless mass on the dorsum of his wrist, which transilluminates. It fluctuates in size and becomes more prominent with wrist flexion. What is the MOST likely diagnosis?