10. Pathology and Oncology MCQs

A 15-year-old boy presents with sudden shoulder pain after throwing a baseball. Radiographs demonstrate a pathologic fracture through an expansile, eccentric, radiolucent metaphyseal lesion in the proximal humerus.

MRI shows multiple fluid-fluid levels within the lesion. An open biopsy reveals blood-filled cavernous spaces lacking an endothelial lining. If this lesion is primary in nature, cytogenetic analysis is most likely to reveal an upregulation of which of the following genes?

A 9-year-old boy undergoes evaluation for mild shoulder discomfort. A radiograph reveals a centrally located, purely lytic lesion in the proximal humerus diaphysis with thinning of the cortices. A 'fallen leaf' sign is noted.

Diagnostic aspiration yields clear, serous yellow fluid. Laboratory analysis of this fluid is most likely to show markedly elevated levels of which of the following compared to normal serum?

A 40-year-old man presents with chronic knee swelling and episodes of hemarthrosis without any history of trauma. MRI of the knee demonstrates a diffuse, nodular synovial proliferation with a prominent 'blooming artifact' on gradient-echo sequences.

Biopsy confirms pigmented villonodular synovitis (PVNS). The pathogenesis of this condition involves a translocation typically resulting in the overproduction of which molecule?

A 19-year-old man complains of localized pain in the proximal tibia that is significantly worse at night. He reports that over-the-counter ibuprofen provides dramatic relief within 30 minutes. Plain radiographs demonstrate an area of dense cortical thickening with a small 8-mm radiolucent central nidus.

The intense nocturnal pain characteristic of this lesion is mediated by a tremendously increased local concentration of which substance?

A 22-year-old man presents with a painful, enlarging mass in his distal femur. A core needle biopsy reveals a highly pleomorphic spindle cell neoplasm producing fine, lace-like osteoid matrix. The patient's family history is significant for a mother who died of breast cancer at age 35 and a sister who was treated for a childhood adrenocortical carcinoma. Which of the following genetic syndromes is most strongly associated with an increased risk of developing this specific bone tumor?

A 10-year-old boy is evaluated for several months of severe thigh pain that is notably worse at night and dramatically relieved by taking ibuprofen. Radiographs and subsequent CT imaging reveal a 7 mm radiolucent nidus surrounded by dense reactive cortical sclerosis in the proximal femoral diaphysis. Which of the following inflammatory mediators is produced in abnormally high concentrations by the cells within this lesion, directly causing the patient's classic pain symptoms?

A 14-year-old girl is diagnosed with a highly aggressive, small blue cell tumor involving the diaphysis of her right femur. Cytogenetic and molecular analysis confirms the diagnosis of Ewing sarcoma. This malignancy is classically characterized by a specific balanced reciprocal translocation that creates an aberrant fusion transcription factor. Which of the following translocations is most specific to this disease process?

A 45-year-old woman is evaluated for a slowly enlarging, painful mass in her proximal humerus. Imaging demonstrates a medullary lesion with 'rings and arcs' calcification. Biopsy confirms an atypical cartilaginous tumor (grade 1 central chondrosarcoma). Recent advances in molecular pathology have identified a specific somatic mutation common to both solitary enchondromas and central chondrosarcomas. Which of the following genes is most likely mutated in this patient's tumor?

A 12-year-old girl presents with swelling and pain in her left distal femur. Radiographs show a rapidly expanding, destructive lytic lesion with a 'blown-out' appearance. Biopsy reveals blood-filled cystic spaces lacking an endothelial lining, separated by cellular fibrous septa containing multinucleated giant cells and reactive woven bone. Which of the following molecular findings is most specific for confirming the diagnosis of a primary aneurysmal bone cyst (ABC)?

You are evaluating the biopsy of articular cartilage from a 25-year-old athlete with a focal chondral defect. The normal articular cartilage surrounding the defect is analyzed. In which zone of the articular cartilage do the collagen fibers orient perpendicular to the subchondral bone, and what is the predominant type of collagen?

A 22-year-old man presents with a 6-month history of dull aching pain in his posterior thoracic spine. The pain is persistent and not reliably relieved by NSAIDs. A CT scan shows a 2.5-cm expansile radiolucent lesion in the posterior elements of T10 with surrounding reactive sclerosis. Histology shows interlacing trabeculae of woven bone with prominent osteoblastic rimming and vascular connective tissue, but no cellular atypia. Which of the following is the most likely diagnosis?

A 12-year-old girl presents with progressive pain and swelling in her mid-thigh. Radiographs show a permeative diaphyseal lesion in the femur with a prominent 'onion-skin' periosteal reaction. A core needle biopsy reveals sheets of small round blue cells. Molecular genetic testing of the biopsy specimen is most likely to show which of the following chromosomal translocations?

A 14-year-old boy presents with persistent knee pain for 3 months. Radiographs demonstrate a 2-cm epiphyseal radiolucent lesion in the proximal tibia with a thin sclerotic rim. MRI shows extensive surrounding bone marrow edema. Histologic examination of a biopsy specimen reveals sheets of mononuclear cells with characteristic nuclear grooves and focal areas of 'chicken-wire' pericellular calcification. Which of the following is the most appropriate management?

A 16-year-old girl is evaluated for a painful, enlarging mass about her distal thigh. Radiographs reveal a destructive, bone-forming metaphyseal lesion of the distal femur with a sunburst periosteal reaction and Codman triangle. Biopsy confirms the diagnosis of conventional osteosarcoma. Alterations in which of the following cellular mechanisms are most strongly implicated in the pathogenesis of this condition?

A 10-year-old boy presents with a 2-month history of worsening thigh pain, particularly at night, accompanied by intermittent low-grade fever. Radiographs show a permeative, diaphyseal radiolucent lesion in the femur with a lamellated 'onion-skin' periosteal reaction. Biopsy reveals sheets of uniform small round blue cells that express high levels of MIC2 (CD99). Molecular analysis is most likely to identify which of the following chromosomal translocations?

A 22-year-old man presents with severe right leg pain that predictably awakens him at night but is completely relieved within 30 minutes of taking ibuprofen. Radiographs demonstrate cortical thickening in the anterior tibial diaphysis. CT scan confirms a 9-mm radiolucent nidus with central calcification surrounded by dense reactive bone. After 6 months of conservative management, the patient requests definitive treatment due to gastrointestinal intolerance of NSAIDs. Which of the following is the most appropriate next step in management?

A 15-year-old boy presents with a painful, destructive diaphyseal lesion of the femur with a large soft tissue extension. A core needle biopsy reveals sheets of uniform small round blue cells. Cytogenetic analysis is most likely to identify which of the following chromosomal translocations?

A 15-year-old boy presents with progressive knee pain. Radiographs demonstrate a destructive diaphyseal lesion of the distal femur with an associated 'onion-skin' periosteal reaction. A subsequent incisional biopsy reveals sheets of uniform, small, round blue cells. Immunohistochemistry demonstrates strong membranous staining for CD99. A molecular cytogenetic test reveals a t(11;22) translocation. What is the most likely diagnosis?

A 15-year-old boy presents with an aggressive diaphyseal lesion in his right femur. A biopsy demonstrates sheets of small round blue cells. Cytogenetic analysis reveals a t(11;22) translocation. Which of the following fusion genes is most likely present?

A 14-year-old boy presents with a destructive diaphyseal lesion of the femur with a large soft tissue mass. Biopsy reveals uniform small blue cells. Which of the following cytogenetic abnormalities is most characteristic of this tumor?