10. Pathology and Oncology MCQs

A 55-year-old man complains of vague lower back pain and constipation for the past 6 months. A digital rectal examination reveals a firm presacral mass. MRI shows a large, destructive midline lesion of the sacrum. Biopsy demonstrates lobules of large, vacuolated cells with abundant mucinous cytoplasm (physaliferous cells) set in a myxoid stroma. Which of the following is the most appropriate definitive surgical management?

A 45-year-old man presents with chronic hip pain. Radiographs demonstrate an expansile, lytic lesion in the proximal femoral epiphysis with central calcifications. The physeal plates are closed. Biopsy reveals sheets of large cells with abundant clear cytoplasm and distinct cell membranes, interspersed with trabeculae of woven bone. What is the most likely diagnosis?

A 12-year-old boy presents with a painful, enlarging mass in the diaphysis of the femur. Radiographs show a permeative lytic lesion with an 'onion skin' periosteal reaction. Biopsy reveals sheets of uniform small round blue cells that strongly express CD99 on immunohistochemistry. Which of the following chromosomal translocations is most characteristic of this patient's diagnosis?

A 32-year-old woman presents with a large, expansile lytic epiphyseal lesion in her distal femur. Biopsy confirms a giant cell tumor of bone. Due to the extensive size and proximity to the articular surface, the surgeon decides to use neoadjuvant medical therapy to consolidate the tumor and facilitate joint-salvage surgery. Which of the following is the mechanism of action of the most appropriate pharmacological agent?

A 55-year-old man complains of severe, generalized bone pain and proximal muscle weakness. Laboratory studies reveal severe hypophosphatemia, normal serum calcium, normal parathyroid hormone (PTH), and low 1,25-dihydroxyvitamin D levels. A small soft-tissue mass is discovered on the plantar aspect of his foot. Complete resection of this mass is most likely to reverse his symptoms by eliminating the abnormal paraneoplastic production of which of the following substances?

A 28-year-old man presents with chronic, dull anterior leg pain. Radiographs reveal a multiloculated, expansile, eccentric lytic lesion involving the anterior cortex of the tibial diaphysis. Histological examination shows islands of epithelial cells interspersed within a fibrous stroma. Immunohistochemistry is strongly positive for cytokeratin. What is the most appropriate definitive management for this lesion?

A 62-year-old man presents with a destructive lytic bone lesion in his proximal humerus. Further workup reveals a primary renal mass consistent with clear cell renal carcinoma. He is scheduled for wide excision and endoprosthetic reconstruction of the humerus. To minimize severe intraoperative complications, which of the following interventions should be strongly considered 24 to 48 hours prior to the orthopedic surgery?

A 19-year-old male presents with severe right thigh pain that is distinctly worse at night and dramatically relieved by over-the-counter ibuprofen. Radiographs reveal localized cortical thickening in the proximal femoral diaphysis with a central 7-mm radiolucent nidus. The dramatic pain relief provided by NSAIDs in this condition is directly mediated by the inhibition of which substance produced by the nidus?

A 15-year-old boy presents with right knee pain of three months duration. Radiographs demonstrate a well-circumscribed, 2-cm lytic lesion with a thin sclerotic margin located entirely within the epiphysis of the distal femur. Fine stippled calcifications are noted internally. Histopathology reveals mononuclear cells with longitudinal nuclear grooves ('coffee bean' nuclei), scattered osteoclast-like giant cells, and areas of 'chicken-wire' calcification. What is the most likely diagnosis?

A 45-year-old man presents with a painless, deep, 10-cm soft-tissue mass in his posterior thigh. MRI shows a well-defined intramuscular mass that is markedly hyperintense on T2-weighted sequences. Core needle biopsy confirms myxoid liposarcoma. Compared to other high-grade soft tissue sarcomas, this specific subtype is uniquely characterized by which of the following clinical behaviors?

A 12-year-old boy presents with a painful mass in his left mid-thigh. Radiographs demonstrate a diaphyseal permeative lytic lesion of the femur with an 'onion skin' periosteal reaction. Core needle biopsy reveals sheets of small, round, blue cells that stain positive for CD99. Which of the following is the most common cytogenetic abnormality associated with this condition?

A 28-year-old man presents with a slow-growing, painless mass deep in the plantar aspect of his left foot. Core needle biopsy demonstrates a biphasic histologic pattern consisting of both uniform spindle cells and epithelial cells forming glandular structures.

Which of the following translocations is classically diagnostic for this soft-tissue tumor?

A 19-year-old man presents with a 6-month history of a dull, aching pain in his right proximal femur that is notably worse at night and dramatically relieved by taking nonsteroidal anti-inflammatory drugs. CT imaging reveals a 7-mm radiolucent nidus surrounded by dense, reactive sclerosis. Histologic examination of the central nidus would most likely reveal which of the following?

A 12-year-old boy presents with an enlarging, painful mass over his right thigh. Radiographs demonstrate a large, ill-defined, destructive diaphyseal lesion of the femur with a prominent 'onion-skin' periosteal reaction. Core needle biopsy reveals sheets of small, uniform, round blue cells. Which of the following cytogenetic abnormalities is most likely present in this tumor?

A 28-year-old man presents with a slowly enlarging, painful mass deep within his plantar foot. Magnetic resonance imaging demonstrates a well-circumscribed, multilobulated mass adjacent to the plantar fascia. Core needle biopsy demonstrates a biphasic tumor with both epithelial and spindle cell components. Which of the following is true regarding this specific soft tissue sarcoma?