10. Pathology and Oncology MCQs

A 14-year-old boy has a permeative lesion in the femoral diaphysis with an onion-skin periosteal reaction. Biopsy shows sheets of uniform small, blue, round cells. Which genetic translocation is most characteristic of this tumor?

A 70-year-old man with a history of Paget disease presents with new, severe pain and swelling in his thigh. Radiographs show cortical destruction and a soft tissue mass arising from a previously thickened, bowed femur. What is the most likely diagnosis?

A 45-year-old woman presents with a deep intramuscular mass in her thigh. Biopsy reveals uniform round to oval cells in a myxoid stroma with a delicate, branching chicken-wire capillary network. This tumor is characterized by which of the following translocations?

A patient with multiple enchondromas and numerous soft-tissue hemangiomas is at the highest risk for developing which of the following complications?

A 20-year-old woman presents with an expansile, lytic lesion in the proximal humerus. MRI shows multiple fluid-fluid levels. Genetic testing of the biopsy tissue reveals a USP6 gene rearrangement. What is the most likely diagnosis?

A 30-year-old female presents with a painless, slow-growing mass in the posterior thigh. MRI shows a poorly circumscribed mass within the muscle. Biopsy reveals spindle cells with abundant collagen, lacking nuclear atypia. Immunohistochemistry shows nuclear beta-catenin expression. Which condition is most strongly associated with this tumor?

A 65-year-old male presents with generalized bone pain and fatigue. Radiographs show multiple punched-out lytic lesions in the skull and long bones. A technetium-99m bone scan is negative in the areas of the lytic lesions. What is the most common laboratory abnormality associated with this condition?

A 28-year-old female presents with recurrent knee swelling and catching. MRI demonstrates a nodular intra-articular soft tissue mass with significant blooming artifact on gradient-echo sequences. What is the underlying pathogenesis of this condition?

A 10-year-old boy is diagnosed with alveolar rhabdomyosarcoma of the forearm. Which of the following genetic translocations is most characteristic of this specific subtype and confers a poorer prognosis compared to embryonal variants?

A 25-year-old female presents with a painless, densely ossified mass attached to the posterior cortex of the distal femur. MRI shows no medullary involvement. Histology reveals mature bone trabeculae separated by a bland fibrous stroma. Amplification of which gene is characteristic of this lesion?

A 55-year-old patient undergoes resection of a large, high-grade soft tissue sarcoma of the thigh. The pathology report notes microscopically positive margins (R1 resection) along a major neurovascular bundle that was deliberately preserved. What is the most appropriate next step in management to optimize local control?

A 24-year-old woman presents with a slowly enlarging, painful mass in her plantar midfoot. Radiographs show a soft tissue mass with stippled calcifications. Biopsy reveals a biphasic spindle cell neoplasm. Which of the following cytogenetic abnormalities is most characteristic of this lesion?

A 45-year-old man presents with chronic hip pain. Radiographs reveal a lytic epiphyseal lesion in the proximal femur with central calcification. Histology shows cells with abundant clear cytoplasm and distinct boundaries mixed with areas of conventional chondrosarcoma. What is the most appropriate definitive management?

A 14-year-old boy undergoes neoadjuvant chemotherapy followed by limb-salvage surgery for classic high-grade osteosarcoma of the distal femur. Which of the following is the most important prognostic factor for his long-term overall survival?

A 62-year-old man with a history of renal cell carcinoma presents with progressive severe right arm pain. Radiographs show a large destructive lytic lesion in the humeral diaphysis with impending fracture. What is the most critical step prior to proceeding with surgical stabilization?

A 58-year-old man presents with a painful mass in his proximal humerus. Radiographs show a lesion with intra-lesional pop-corn calcifications and an adjacent aggressive lytic component destroying the cortex. Biopsy reveals a low-grade cartilage tumor abruptly transitioning to a high-grade spindle cell sarcoma. What is the most likely diagnosis?

A 12-year-old boy presents with a permeative lytic lesion in the tibial diaphysis with an associated "onion skin" periosteal reaction. Biopsy shows sheets of small round blue cells that stain positive for CD99 and PAS, but negative for reticulin. Which of the following fusion genes is most likely present?

A 28-year-old woman presents with a slow-growing, painless mass on the posterior aspect of her distal femur. Imaging shows a heavily ossified, lobulated mass attached to the posterior cortex by a broad stalk, with a cleavage plane visible between the tumor and the underlying bone. Amplification of which gene is characteristic of this lesion?

A 55-year-old man presents with progressive bowel and bladder dysfunction. An MRI of the sacrum reveals a destructive midline mass centered at S3. Biopsy shows lobules of vacuolated (physaliferous) cells with abundant mucoid stroma. Immunohistochemistry is positive for brachyury and cytokeratin. What is the most appropriate surgical management?

A 10-year-old child who survived bilateral retinoblastoma in infancy presents with a new onset of pain and swelling in the distal femur. Radiographs reveal a mixed lytic and sclerotic lesion with a Sunburst periosteal reaction. Given the patient's genetic history, what is the most likely diagnosis of this secondary malignancy?