10. Pathology and Oncology MCQs

A 60-year-old man presents with a massive, deep intramuscular mass in his proximal thigh. Biopsy reveals a well-differentiated liposarcoma. He undergoes marginal excision, but the tumor recurs rapidly 18 months later. Re-biopsy of the recurrence shows areas of high-grade, non-lipogenic sarcoma consistent with dedifferentiation. Molecular analysis of both the primary and recurrent tumor will show amplification of:

A 55-year-old man presents with progressive pelvic pain. Radiographs reveal a large, expansile radiolucent lesion in the ilium with internal 'rings and arcs' calcifications. Biopsy demonstrates hypercellular hyaline cartilage with nuclear atypia and myxoid changes. Which of the following gene mutations is most frequently implicated in the pathogenesis of this tumor?

A 25-year-old man presents with a slow-growing, painful mass near his ankle joint. MRI shows a soft tissue mass adjacent to, but not communicating with, the joint space. Biopsy reveals a biphasic pattern consisting of epithelial elements forming gland-like structures and a spindle cell stroma. Which of the following chromosomal translocations is characteristic of this lesion?

A 16-year-old girl complains of localized pain in her proximal humerus. Radiographs show an eccentric, expansile, lytic metaphyseal lesion with cortical thinning. MRI reveals multiple fluid-fluid levels. Biopsy shows blood-filled cystic spaces lacking an endothelial lining. Which of the following genetic alterations is diagnostic for the primary form of this lesion?

A 45-year-old man has a large, painless mass deep in his posterior thigh. Histologic examination reveals uniform, small, round to oval cells, scattered lipoblasts, and a prominent arborizing capillary network described as 'chicken wire' vasculature in a myxoid background. Which translocation is diagnostic?

A 14-year-old boy presents with knee pain. Radiographs show a well-defined lytic lesion in the epiphysis of the proximal tibia with a sclerotic rim. Biopsy reveals mononuclear cells with longitudinal nuclear grooves and 'chicken wire' calcifications. Which of the following gene mutations is highly specific for this tumor?

A 30-year-old woman presents with a slow-growing nodule attached to her Achilles tendon. The tumor consists of nests of uniform spindle cells with clear cytoplasm separated by dense fibrous septa. Immunohistochemistry is positive for HMB-45 and S-100. What is the associated cytogenetic abnormality?

A 35-year-old woman reports recurrent knee swelling without trauma. Joint aspiration yields brownish fluid. MRI reveals a thickened synovium with hypointense nodules on T2-weighted imaging showing 'blooming' artifact. The pathogenesis of this condition is driven by a translocation leading to the overexpression of which factor?

A 60-year-old man presents with insidious onset of sacral pain and recent bowel/bladder incontinence. Imaging reveals a destructive midline sacral mass. Biopsy shows large cells with copious bubbly cytoplasm in a myxoid stroma. Which immunohistochemical marker is highly specific for the presumed diagnosis?

A 20-year-old man presents with an aching back pain that is poorly relieved by NSAIDs. Imaging reveals a 3.5 cm lytic lesion with a sclerotic rim in the posterior elements of L3. Histology shows irregular osteoid trabeculae lined by plump osteoblasts in a highly vascular stroma. What is the most likely diagnosis?

A 15-year-old boy presents with a rapidly growing mass deep in his forearm. Histology demonstrates malignant small round blue cells arranged in nests separated by fibrous septa, forming cleft-like spaces. Molecular testing confirms the presence of which of the following genetic fusions?

A 65-year-old woman with a history of breast cancer treated with local radiation 15 years ago presents with severe shoulder pain. Radiographs show a destructive, permeative lytic lesion in the proximal humerus with an aggressive periosteal reaction. Biopsy confirms a secondary bone sarcoma. What is the most common histologic subtype in this setting?

A 25-year-old man presents with jaw pain. Imaging reveals a well-defined lytic lesion in the mandible. Histology shows abundant interlacing collagen fibers and bland spindle cells, identical to a soft-tissue desmoid tumor. It is locally aggressive. What is the diagnosis?

A 30-year-old woman presents with a painless, hard mass behind her knee. Radiographs reveal a heavily ossified, lobulated mass attached to the posterior cortex of the distal femur by a broad base, with a visible radiolucent cleft (string sign). Which molecular hallmark is diagnostic of this condition?

A 14-year-old boy presents with knee pain. Radiographs show an eccentric epiphyseal lytic lesion in the proximal tibia with a sclerotic margin. Biopsy shows polyhedral mononuclear cells with grooved nuclei and scattered multinucleated giant cells with fine chicken-wire calcifications. Which of the following mutations is most characteristic of this lesion?

A 35-year-old woman presents with a slow-growing mass on the posterior aspect of her distal femur. Radiographs reveal a heavily ossified, broad-based mass attached to the cortex with a radiolucent cleft between the mass and bone. Histology shows well-differentiated bone trabeculae and a low-grade fibroblastic stroma. Which of the following genetic alterations is most specific for this diagnosis?

A 25-year-old man presents with a painful swelling in his right foot. MRI shows a soft tissue mass with high signal on T2. Biopsy reveals spindle cells and epithelial cells forming glandular structures. The tumor is positive for cytokeratin, EMA, and TLE1. Which of the following translocations is diagnostic?

A 10-year-old girl is evaluated for precocious puberty, irregular cafe-au-lait spots, and multiple lytic bone lesions exhibiting a ground-glass appearance. Biopsy of a bone lesion shows curvilinear woven bone lacking osteoblastic rimming. The pathogenesis of this syndrome involves a mutation in a gene encoding which of the following?

A 40-year-old man presents with a locally aggressive soft tissue mass in the deep tissues of his thigh. Biopsy shows a biphasic population of osteoclast-like giant cells and mononuclear cells, with abundant hemosiderin deposition. Cytogenetic analysis identifies a t(1;2)(p13;q37) translocation. The targeted therapy for severe, unresectable cases typically inhibits which of the following?