10. Pathology and Oncology MCQs

A 16-year-old male is receiving neoadjuvant chemotherapy for osteosarcoma using the standard MAP regimen (Methotrexate, Doxorubicin, Cisplatin). He subsequently develops irreversible congestive heart failure. Which of the chemotherapeutic agents is most likely responsible for this specific toxicity?

A 55-year-old male presents with chronic back pain and bowel/bladder dysfunction. Imaging reveals a destructive, midline lesion centered in the sacrum. Biopsy demonstrates lobules of large cells with abundant vacuolated cytoplasm (physaliferous cells) set in a myxoid background. The tumor cells are most likely to show strong immunohistochemical positivity for which of the following markers?

A 20-year-old female presents with mild chronic leg pain. Radiographs show an eccentric, lytic, expansile lesion in the proximal tibial metaphysis with a well-defined, scalloped sclerotic margin. Histology reveals a pseudolobular architecture with stellate to spindle-shaped cells in a myxoid stroma, and osteoclast-like giant cells at the lobule peripheries. What is the diagnosis?

A patient diagnosed with polyostotic fibrous dysplasia presents with a newly discovered, painless, deep soft tissue mass in the thigh. Excisional biopsy of the mass reveals a well-circumscribed lesion composed of bland spindle cells in an abundant myxoid stroma with decreased vascularity. The presence of this soft tissue lesion in conjunction with fibrous dysplasia is known as:

A 28-year-old female presents with a painless mass behind her knee. Radiographs reveal a densely ossified mass attached to the posterior cortex of the distal femur by a broad base, with a radiolucent cleft between the tumor and the underlying bone cortex (string sign). Molecular analysis of this tumor is most likely to reveal an amplification of which of the following?

A 40-year-old male undergoes wide excision of a deep thigh mass, which is diagnosed histologically as a myxoid liposarcoma (t(12;16) translocation). Unlike most soft tissue sarcomas of the extremities, which primarily metastasize to the lungs, myxoid liposarcoma has a uniquely high propensity to metastasize to which of the following locations?

A 28-year-old female presents with a painless mass on the posterior aspect of her distal thigh. Radiographs show a densely ossified mass attached to the posterior femoral cortex with a broad base and no medullary involvement. Which genetic amplification is most specific to this lesion?

A 24-year-old male presents with a slowly enlarging, painless mass near his knee joint. MRI reveals a deep soft-tissue mass adjacent to the joint capsule with small areas of calcification. Biopsy confirms a malignant biphasic tumor. Which chromosomal abnormality is diagnostic?

A 65-year-old male with a history of renal cell carcinoma presents with a painful destructive lesion in his subtrochanteric femur. Mirels' score is 10. Prophylactic fixation is planned. What is the most critical step prior to surgical intervention?

A 55-year-old male presents with bowel and bladder dysfunction and sacral pain. Imaging reveals a midline destructive sacral lesion. Histology shows physaliferous cells with vacuolated cytoplasm. Which immunohistochemical marker is highly specific for this diagnosis?

An 18-year-old female presents with a rapidly expanding, painful lytic lesion in her distal fibula. MRI shows an expansile lesion with multiple fluid-fluid levels. Genetic analysis reveals a characteristic rearrangement. Which gene is primarily involved?

A 32-year-old male presents with an anterior tibial bowing deformity and pain. Radiographs reveal a multiloculated, expansile, eccentric intracortical radiolucency in the tibial diaphysis. Histology shows biphasic spindle and epithelial cells. What is the most appropriate definitive surgical treatment?

A 68-year-old female complains of generalized bone pain and fatigue. Radiographs show multiple "punched-out" lytic lesions in her skull and pelvis. A bone scan shows no increased uptake in these areas. Which of the following laboratory findings is most likely to confirm the diagnosis?

A 50-year-old male undergoes wide resection of a high-grade pleomorphic sarcoma of the thigh. He receives preoperative radiation therapy. Compared to postoperative radiation, preoperative radiation is associated with which of the following?

A 14-year-old boy presents with chronic knee pain. Radiographs reveal a well-circumscribed, 2 cm lytic lesion in the proximal tibial epiphysis with a thin sclerotic margin and central calcifications. What is the most common histological finding associated with this tumor?

A 45-year-old male has a large, deep mass in his thigh. Core biopsy confirms myxoid liposarcoma. Which chromosomal translocation is classically associated with this tumor, and where is the most common site of metastasis?

A 19-year-old male presents with persistent, dull aching back pain that is worse at night. The pain is not relieved by ibuprofen. CT imaging reveals a 2.5 cm radiolucent nidus with surrounding sclerosis in the posterior elements of L4. What is the most likely diagnosis?

A 10-year-old girl is evaluated for multiple bony deformities and multiple subcutaneous soft-tissue hemangiomas. Radiographs show multiple cartilaginous lesions within the medullary cavity of her tubular bones. She is at highest risk for developing which of the following malignancies?

A 20-year-old male presents with swelling over the anterior mid-tibia. Imaging reveals a surface lesion with sunburst periosteal reaction, cortical thickening, and no intramedullary involvement. Biopsy shows an intermediate-grade tumor with predominantly chondroblastic matrix. What is the appropriate treatment?

A 24-year-old male presents with chronic axial back pain. He notes that the pain is dull, constant, and only mildly relieved by non-steroidal anti-inflammatory drugs (NSAIDs). Radiographs and a subsequent CT scan reveal a 3.0 cm expansile, lytic lesion in the posterior elements of L4. Histologically, the lesion shows a loose fibrovascular stroma with interlacing trabeculae of osteoid lined by prominent osteoblasts. What is the most likely diagnosis?