10. Pathology and Oncology MCQs

According to the Enneking surgical staging system for musculoskeletal tumors, what defines a Stage IIB sarcoma?

During an emergent open reduction and internal fixation, the patient develops sudden tachycardia, muscle rigidity, and a rapidly rising core body temperature. The anesthesia team administers a life-saving medication. What is the mechanism of this drug?

A 15-year-old male presents with night pain in his femur that is dramatically relieved by NSAIDs. A CT scan shows a small radiolucent nidus surrounded by dense reactive sclerosis. What is the primary mediator secreted by this lesion that causes the characteristic pain?

A 14-year-old female is diagnosed with conventional high-grade osteosarcoma of the distal femur. Genetic analysis of the tumor is most likely to reveal a somatic mutation or inactivation in which of the following genes?

A 15-year-old boy presents with pain and swelling around his distal femur. Radiographs reveal a sunburst periosteal reaction and a Codman triangle. Biopsy confirms osteosarcoma. Germline mutations in which of the following tumor suppressor genes are most classically associated with an increased risk for this malignancy?

A 28-year-old male presents with a deep, slow-growing soft tissue mass in the popliteal fossa. Biopsy reveals a biphasic tumor with both spindle cells and epithelial cells. Which of the following chromosomal translocations is highly specific to this diagnosis?

A 15-year-old boy presents with severe night pain in his proximal femur that is dramatically relieved by oral ibuprofen. Imaging confirms a cortically based lesion with a small radiolucent nidus. The symptomatic relief provided by NSAIDs is directly related to the inhibition of which of the following?

A 14-year-old girl is diagnosed with osteosarcoma of the distal femur. Her family history is notable for her mother having premenopausal breast cancer and her brother having a soft tissue sarcoma. A germline mutation in which gene is the most likely underlying cause?

Which of the following chromosomal translocations is classically associated with Ewing sarcoma, leading to the formation of a chimeric transcription factor?

A 14-year-old boy presents with progressive knee pain and swelling. Radiographs show a permeative, destructive diaphyseal lesion of the femur with a large soft tissue mass and an 'onion skin' periosteal reaction. Biopsy reveals small round blue cells. Which chromosomal translocation is the diagnostic hallmark of this tumor?

A 19-year-old male reports persistent nocturnal diaphyseal tibial pain that is dramatically relieved by aspirin. Radiographs reveal a cortically based sclerotic lesion with a central radiolucent nidus measuring 8 mm. What is the primary biochemical mediator produced in high quantities by the nidus responsible for the patient's specific pain pattern?

A 55-year-old male with a history of renal cell carcinoma presents with a large, solitary, highly destructive lytic lesion in the proximal diaphyseal femur with an impending pathologic fracture. What is the most critical step prior to proceeding with prophylactic intramedullary stabilization?

A 14-year-old boy presents with a painful, swollen mass on his left diaphyseal femur. Radiographs reveal a permeative, destructive lesion with an "onion-skin" periosteal reaction. Biopsy confirms small round blue cells. Immunohistochemistry is most likely to be strongly positive for which of the following markers?

A 15-year-old boy presents with a destructive diaphyseal lesion of the femur with a large soft tissue mass. Biopsy reveals small round blue cells. Which of the following chromosomal translocations is most pathognomonic for this tumor?

A 60-year-old female with a history of breast cancer presents with severe thigh pain. Radiographs reveal a 3 cm lytic lesion in the peritrochanteric region of the femur involving 50% of the cortical diameter. What is her Mirels' score, and what is the recommended treatment?

A 14-year-old boy presents with a diaphyseal femur lesion with an "onion skin" periosteal reaction. Biopsy reveals small round blue cells. Which of the following chromosomal translocations is most pathognomonic for this tumor?

A 45-year-old female with a history of breast cancer presents with progressively worsening proximal femur pain. Radiographs demonstrate a large lytic lesion. You calculate a Mirels score to determine the need for prophylactic fixation. Which of the following is NOT a parameter used in the Mirels scoring system?

A 14-year-old boy presents with a painful, swollen thigh. Radiographs reveal a permeative, diaphyseal lesion with an 'onion-skin' periosteal reaction. A biopsy is planned. Which of the following chromosomal translocations is most pathognomonic for the suspected diagnosis?

A 19-year-old male complains of severe, aching pain in his proximal femur that is notably worse at night and dramatically relieved by ibuprofen. Radiographs demonstrate a 1-cm radiolucent nidus surrounded by dense reactive sclerosis. What is the most appropriate initial management?