10. Pathology and Oncology MCQs

A 25-year-old male presents with a long-standing anterior bowing deformity of his tibia and new-onset pain. Radiographs reveal a multi-loculated, "bubbly" diaphyseal osteolytic lesion. Biopsy shows nests of epithelial cells in a fibrous stroma. This tumor is most likely to be strongly positive for which marker?

A 30-year-old woman presents with a deep, firm mass in her right ankle. Biopsy shows nests of pale spindle cells separated by fibrous septa. Immunohistochemistry is strongly positive for S100 and HMB-45. What is the characteristic chromosomal translocation for this tumor?

A 25-year-old male presents with a deep, slow-growing soft tissue mass in the posterior thigh. Core needle biopsy reveals a biphasic tumor consisting of both epithelial and spindle cell components. Which of the following chromosomal translocations is highly specific and diagnostic for this malignancy?

A 16-year-old boy presents with severe localized knee pain and a destructive, sunburst-pattern bone lesion in the distal femoral metaphysis. Biopsy reveals highly pleomorphic spindle cells. The definitive histologic criterion for diagnosing this lesion as conventional osteosarcoma rather than a high-grade undifferentiated pleomorphic sarcoma is the presence of:

A 12-year-old girl presents with a "shepherd's crook" deformity of the proximal femur.

Radiographs show a classic ground-glass appearance. The underlying condition is driven by a genetic mutation that results in the constitutive activation of which of the following?

An 11-year-old boy presents with a painful mass in the diaphysis of his femur. Radiographs show an aggressive, permeative lytic lesion with an 'onion-skin' periosteal reaction. Biopsy reveals small round blue cells. Which of the following immunohistochemical markers and translocations are most characteristic of this lesion?

A 25-year-old man presents with a slow-growing, deep-seated mass in his popliteal fossa. Imaging reveals a soft tissue mass with punctate calcifications. Biopsy demonstrates a biphasic spindle cell neoplasm with epithelial components. What is the pathognomonic chromosomal translocation associated with this tumor?

A 22-year-old man presents with an anterior tibial bowing deformity and a multi-loculated, lytic 'soap-bubble' lesion in the anterior cortex of the tibial diaphysis. Biopsy shows islands of epithelial cells surrounded by fibrous stroma. Immunohistochemistry is positive for cytokeratin. What is the most appropriate definitive management?

An 18-year-old male complains of severe, progressively worsening nocturnal thigh pain that is completely relieved by ibuprofen. Radiographs reveal a cortical thickening with a 7mm radiolucent nidus. Which of the following is true regarding the pathophysiology of his pain?

A 32-year-old woman presents with a firm mass in her foot, firmly attached to the plantar fascia. Biopsy shows nests of uniform cells with clear cytoplasm separated by fibrous septa. The cells are strongly positive for S-100 and HMB-45. Which of the following translocations is diagnostic for this tumor?

A 25-year-old male presents with multiple asymmetric cartilaginous tumors in his hands and long bones. He also has multiple soft tissue hemangiomas on his trunk and extremities. What is his most likely underlying diagnosis, and what gene mutation is most commonly associated with it?

An 18-year-old female sustains a pathologic fracture of her proximal humerus. Radiographs show an expansile, eccentrically placed, radiolucent lesion with 'fluid-fluid' levels on MRI. Biopsy shows blood-filled spaces lacking an endothelial lining and scattered giant cells. Which genetic alteration is primarily responsible for the primary form of this lesion?

A 35-year-old man presents with recurrent bloody effusions and chronic swelling in his knee. MRI reveals a large, lobulated intra-articular mass with low signal intensity on both T1 and T2 weighted images, with prominent blooming artifact on gradient-echo sequences. What is the characteristic genetic translocation and resulting molecular driver of this condition?

A 45-year-old male undergoes wide resection of a massive, painless, deep-seated soft tissue mass in his thigh. Pathology reveals a uniform proliferation of round cells, signet-ring lipoblasts, and a prominent plexiform ('chicken-wire') capillary network in a myxoid stroma. Which genetic abnormality is highly specific for this sarcoma?

A 55-year-old man presents with a pathologic fracture of his right femur. Radiographs reveal an aggressive, blastic (sclerotic) lesion in the proximal femur. Which of the following primary malignancies is the most likely source of this metastasis?

A 25-year-old woman presents with a slow-growing mass on the posterior aspect of her distal femur. Radiographs show a heavily ossified, broad-based mass originating from the cortical surface without medullary involvement. Histology reveals low-grade spindle cells with abundant osteoid formation. What is her expected 5-year survival with wide surgical resection alone?

A 16-year-old boy presents with a rapidly enlarging mass in his forearm. Biopsy shows small round blue cells arranged in nests separated by fibrous septa, with a loss of central cellular cohesion mimicking pulmonary alveoli. Immunohistochemistry is strongly positive for MyoD1 and myogenin. Which translocation implies the worst prognosis for this specific tumor type?

A 45-year-old male presents with chronic knee pain. Radiographs reveal a lytic lesion in the proximal tibial epiphysis with faint mineralization. Biopsy shows lobules of cells with abundant clear cytoplasm and distinct boundaries, interspersed with reactive woven bone formation. Which of the following is the most likely diagnosis?

A 28-year-old female undergoes resection of a deep-seated soft tissue mass near her knee joint. Histology demonstrates a biphasic pattern of spindle cells and epithelial-like glandular structures. Which of the following chromosomal translocations is characteristic of this tumor?