10. Pathology and Oncology MCQs

A 65-year-old male presents with a pathologic fracture through a proximal femur lesion. Biopsy reveals regions of low-grade hyaline cartilage abruptly transitioning into a high-grade, non-cartilaginous spindle cell sarcoma. Which of the following is the most likely diagnosis?

A 24-year-old female presents with a painless mass on the posterior aspect of her distal femur. Radiographs demonstrate a heavily ossified, broad-based surface lesion appearing 'stuck on' the cortex, with no medullary involvement. Molecular analysis of this tumor is most likely to reveal an amplification of which gene?

A 12-year-old asymptomatic boy incidentally undergoes a radiograph revealing an eccentric, lobulated, bubbly radiolucent lesion with a sclerotic rim in the distal tibia metaphysis. The lesion occupies 60% of the bone diameter. What is the most appropriate management?

A 40-year-old male presents with hip pain. Radiographs reveal a radiolucent epiphyseal lesion in the proximal femur with central calcifications. Biopsy demonstrates sheets of cells with distinct cytoplasmic margins, abundant clear cytoplasm, and interspersed areas of hyaline cartilage. What is the recommended surgical treatment?

A 20-year-old male presents with leg pain. Imaging shows a radiolucent surface lesion on the anterior diaphysis of the tibia with a 'sunburst' periosteal reaction and adjacent cortical thickening, but no medullary involvement. Histology reveals predominantly chondroblastic matrix with intermediate-grade malignant cells. Which of the following is the most likely diagnosis?

A 16-year-old boy presents with severe knee pain. MRI reveals an expansile, metaphyseal lesion in the distal femur with multiple fluid-fluid levels. A contrast-enhanced T1-weighted scan shows thick, nodular enhancement of the internal septations. Which of the following is the most likely diagnosis?

A 35-year-old male with a history of multiple hereditary exostoses presents with a newly enlarging, painful mass on his proximal humerus. MRI demonstrates an osteochondroma with a cartilage cap thickness of 2.5 cm. Which of the following mutations is most strongly associated with his underlying condition?

A 10-year-old girl is found to have multiple non-ossifying fibromas of the lower extremities, axillary freckling, and multiple cafe-au-lait macules. She does not have any cutaneous neurofibromas. Which of the following syndromes best fits this clinical picture?

A 45-year-old woman is diagnosed with an atypical cartilaginous tumor (Grade 1 chondrosarcoma) entirely confined within the medullary canal of the proximal humerus without cortical breakthrough. What is the most appropriate definitive surgical management?

A 15-year-old girl with a history of bilateral leukocoria treated in infancy presents with a lytic, destructive lesion of the proximal tibia associated with a Codman's triangle. The primary mutation predisposing her to this secondary malignancy occurs in a gene whose product normally functions to:

A 30-year-old female undergoes a biopsy for an aggressive, lytic lesion of the ilium. Histopathology demonstrates a biphasic pattern consisting of small, round blue cells and distinct islands of well-differentiated hyaline cartilage. Which of the following best describes the management of this specific subtype of chondrosarcoma?

An 80-year-old male with long-standing Paget's disease presents with a rapidly expanding, painful mass in his left proximal femur, accompanied by a markedly elevated alkaline phosphatase. A biopsy confirms osteosarcoma. Which of the following statements regarding secondary osteosarcoma in Paget's disease is most accurate?

A 55-year-old male is diagnosed with an intermediate-grade (Grade 2) conventional chondrosarcoma located entirely within the iliac wing. What is the most appropriate surgical treatment?

A 17-year-old male is diagnosed with high-grade conventional osteosarcoma of the distal femur. Staging studies should specifically focus on detecting metastasis to which of the following organs, as it is the most common site of initial metastatic spread?

When evaluating plain radiographs to differentiate an enchondroma from a low-grade central chondrosarcoma in the long bones of an adult, which of the following findings is most specific for chondrosarcoma?

The current standard of care for a 16-year-old patient with non-metastatic conventional intramedullary osteosarcoma involves which of the following sequences?

A 28-year-old male with a history of a 'benign cartilage tumor' resected from his distal femur 5 years ago now presents with local recurrence and lung metastases. Review of the original histology most likely showed high-grade spindle cells. Which genetic mutation or amplification is typically required to differentiate a dedifferentiated chondrosarcoma from other high-grade sarcomas?

A 12-year-old male presents with distal thigh pain after running. Radiographs show a 4 cm, eccentric, cortically based lucent lesion in the distal femur occupying 60% of the medullary diameter. A biopsy confirms a non-ossifying fibroma. What is the most appropriate primary indication for surgical intervention in this patient?

A 28-year-old female presents with a slowly enlarging, painless mass at the posterior aspect of her distal femur. Radiographs show a dense, heavily ossified mass attached to the posterior cortex with a broad base and a radiolucent cleft separating it from the underlying bone. Which of the following genetic alterations is most characteristic of this lesion?