10. Pathology and Oncology MCQs

A 19-year-old male complains of severe, aching pain in his right proximal tibia that is worse at night and dramatically relieved by NSAIDs. Imaging shows a 1 cm radiolucent nidus surrounded by dense sclerotic bone. What is the most appropriate definitive management if medical therapy fails?

A 15-year-old presents with knee pain. Radiographs reveal a mixed lytic and sclerotic lesion in the distal femur with an associated Codman triangle. Prior to definitive surgical resection, what is the most critical orthopedic purpose of obtaining a whole-bone MRI of the affected femur?

A 40-year-old female complains of severe, pinpoint pain in her long finger that worsens significantly upon exposure to cold water. Physical examination reveals exquisite point tenderness beneath the nail plate. What is the most likely diagnosis?

A 15-year-old boy presents with knee pain and a mass in the distal femur. A biopsy reveals malignant mesenchymal cells producing osteoid. The patient's family history is significant for a sister who developed breast cancer at age 28 and a mother who died of an adrenocortical carcinoma. Which of the following gene mutations is most likely associated with this patient's underlying syndrome?

A 12-year-old boy presents with a painful, swollen thigh. Radiographs demonstrate a diaphyseal permeative lytic lesion with a periosteal 'onion skin' reaction. Biopsy reveals uniform small round blue cells expressing CD99. Which of the following is the most common cytogenetic abnormality associated with this tumor?

A 55-year-old man presents with a large, painful mass in his pelvis. Biopsy shows a cartilaginous tumor with hypercellularity, pleomorphism, and binucleated cells. Foci of the tumor show abrupt transition to a high-grade, non-cartilaginous spindle cell sarcoma. What is the most likely diagnosis?

A 14-year-old girl sustains a minor fall and complains of persistent arm pain. Radiographs show an expansile, multiloculated, radiolucent lesion in the metaphysis of the humerus. MRI demonstrates multiple fluid-fluid levels. Genetic analysis of the biopsy tissue is most likely to reveal a rearrangement involving which of the following genes?

A 25-year-old man presents with a long history of anterior tibial bowing and pain. Radiographs show a multiloculated, 'soap bubble' radiolucent lesion in the anterior diaphyseal cortex of the tibia. Biopsy reveals a biphasic tumor with both epithelial and osteofibrous components. Immunohistochemistry will be strongly positive for which of the following?

A 40-year-old woman is incidentally found to have a well-circumscribed, lobulated, cartilaginous lesion in the proximal humerus with punctate calcifications. There is no endosteal scalloping or cortical breakthrough. Molecular testing of such lesions frequently demonstrates mutations in which of the following enzymes?

A 60-year-old man presents with chronic low back pain and new-onset bowel incontinence. MRI shows a large, destructive midline mass involving the sacrum. Biopsy reveals lobules of physaliferous cells with a myxoid stroma. Which of the following immunohistochemical markers is most specific for this diagnosis?

A 28-year-old woman presents with a slow-growing, painful mass near her knee joint. MRI shows a heterogeneous soft tissue mass adjacent to, but not within, the knee joint capsule, with calcifications. Core biopsy shows a biphasic tumor with spindle cells and glandular-like epithelial elements. Cytogenetic evaluation is most likely to show which translocation?

A 19-year-old male presents with severe nocturnal pain in his right thigh that is dramatically relieved by ibuprofen. Radiographs show a small radiolucent nidus surrounded by dense reactive sclerosis in the femoral diaphysis. The profound pain relief provided by NSAIDs is primarily due to the high local production of which of the following?

A 35-year-old man undergoes arthroscopy for chronic knee swelling and locking. The synovium is diffusely hypertrophic and reddish-brown. Histology shows mononuclear cells, multinucleated giant cells, and prominent hemosiderin deposition. The pathogenesis of this condition is primarily driven by an overexpression of which of the following?

A 6-year-old boy presents with skull pain and a soft tissue mass over his parietal bone. Radiographs show a 'punched-out' lytic lesion with no sclerotic rim. Biopsy reveals sheets of mononuclear cells with grooved, 'coffee-bean' nuclei admixed with eosinophils. These cells will characteristically test positive for S-100, CD1a, and which other immunohistochemical marker?

A 65-year-old man presents with diffuse back pain, fatigue, and recent weight loss. Laboratory studies show anemia and hypercalcemia. Radiographs demonstrate multiple 'punched-out' lytic lesions in the skull and vertebrae. Bone marrow biopsy is likely to show a proliferation of neoplastic cells that express which of the following surface markers?

A 30-year-old man presents with a slowly enlarging, painful mass bound to the Achilles tendon. Biopsy reveals nests of pale, spindled to epithelioid cells. The cells are strongly positive for S-100, HMB-45, and Melan-A. Molecular testing reveals a t(12;22)(q13;q12) translocation. What is the most appropriate diagnosis?

A 28-year-old woman presents with a slow-growing, painless mass on the posterior aspect of her distal femur. Radiographs reveal a heavily ossified, lobulated mass attached to the posterior cortex by a broad base, with a 'string sign' visible between the tumor and the underlying bone. Histology shows low-grade spindle cells between well-formed trabeculae of woven bone. This tumor is characterized by the amplification of which gene?

A 16-year-old boy presents with right knee pain. Radiographs reveal a well-defined, 2 cm lytic lesion within the epiphysis of the proximal tibia with a thin sclerotic rim. Biopsy demonstrates mononuclear cells with 'chicken-wire' calcifications. Immunohistochemistry of this tumor frequently shows positivity for which of the following?