10. Pathology and Oncology MCQs

A 65-year-old male undergoes marginal excision of a large, deep, fatty thigh mass initially thought to be a lipoma. Pathology reveals an atypical lipomatous tumor (well-differentiated liposarcoma). Amplification of which gene region is the molecular hallmark of this tumor?

A 9-year-old girl presents with a pathologic fracture of the proximal femur with a "shepherd's crook" deformity. She also has precocious puberty and cafe-au-lait spots with irregular borders. The underlying pathophysiology involves a post-zygotic activating mutation in which of the following?

A 25-year-old male presents with a slowly growing, painful mass near the knee joint. MRI shows a soft tissue mass adjacent to the joint capsule with focal calcifications. Biopsy shows a biphasic spindle cell neoplasm. What is the characteristic chromosomal translocation?

A 68-year-old woman presents with generalized bone pain, anemia, and hypercalcemia. Skeletal survey reveals multiple punched-out lytic lesions in the skull and pelvis. Which of the following lab findings is most likely present?

A 30-year-old female presents with a painless, slowly enlarging mass on the posterior aspect of the distal femur. Radiographs demonstrate a dense, ossified mass attached to the posterior cortex with a radiolucent cleft between the tumor and underlying bone. What is the most appropriate management?

A 14-year-old boy presents with knee pain. Radiographs reveal an eccentrically located, sharply marginated lytic lesion with stippled calcifications confined to the proximal tibial epiphysis. Histology shows polygonal cells with longitudinal nuclear grooves and pericellular calcification. What is the diagnosis?

A 20-year-old male complains of severe nocturnal back pain relieved by NSAIDs. Imaging reveals a 2.5 cm lytic lesion with surrounding sclerosis in the posterior elements of L4. What makes this lesion most likely an osteoblastoma rather than an osteoid osteoma?

A 12-year-old girl presents with a rapidly expanding, painful, eccentrically located lytic lesion in the distal femur. MRI reveals multiple fluid-fluid levels. Biopsy confirms an Aneurysmal Bone Cyst (ABC). Primary ABCs are often associated with a recurrent chromosomal translocation resulting in the upregulation of which gene?

A 35-year-old female presents with a slow-growing, painful mass in her anterior tibial diaphysis. Radiographs show a multi-loculated, "soap-bubble" eccentric osteolytic lesion in the anterior cortex. Histology reveals epithelial cell islands in a fibrous stroma. What is the recommended treatment?

A 15-year-old boy completes neoadjuvant chemotherapy for Ewing sarcoma of the fibula. He subsequently undergoes wide resection. Pathologic evaluation of the resected specimen is performed. Which of the following is the most significant prognostic factor for overall survival at this stage?

A 55-year-old woman with metastatic breast cancer presents with thigh pain. Radiographs reveal a mixed blastic and lytic lesion in the pertrochanteric region of the femur. According to Mirels' criteria, which of the following characteristics contributes the highest number of points toward the total score?

A 19-year-old male with Multiple Hereditary Exostoses (MHE) notes a sudden increase in the size of a long-standing painless mass on his proximal medial tibia, now accompanied by pain. What is the most reliable MRI feature suggesting malignant transformation to secondary chondrosarcoma?

A 15-year-old boy presents with an enlarging, painful mass in his distal femur. Radiographs display a "sunburst" periosteal reaction and a Codman triangle. Core needle biopsy reveals malignant osteoid. Genetic testing of the tumor cells is most likely to show abnormalities in which of the following tumor suppressor genes?

A 60-year-old male presents with a large, slow-growing pelvic mass. Imaging shows a lytic lesion with "popcorn" calcifications in the right ilium. Biopsy confirms a grade II (intermediate) chondrosarcoma. What is the most appropriate primary treatment modality?

A 22-year-old male presents with a 6-month history of a dull, aching pain in his posterior thoracic spine that is not relieved by aspirin. CT imaging reveals a 3.5 cm expansile, radiolucent lesion in the T8 posterior elements. What is the most likely diagnosis?

A 65-year-old male with a history of nephrectomy for renal cell carcinoma presents with a destructive, lytic lesion of the proximal humerus and an impending fracture. Prophylactic stabilization with an intramedullary nail is planned. What critical step should be taken prior to surgery?

A 30-year-old female presents with a slow-growing, painful mass deep in the plantar aspect of her foot. Biopsy reveals a biphasic tumor with both epithelial and spindle cell components. Which genetic translocation is diagnostic for this tumor?

A 14-year-old girl presents with a rapidly enlarging, painful mass in her proximal humerus. Radiographs show an eccentric, expansile radiolucent lesion. MRI demonstrates multiple fluid-fluid levels. If a primary neoplastic process is confirmed, which gene rearrangement is characteristic of this lesion?

A 16-year-old boy presents with chronic knee pain. Radiographs reveal a well-defined lytic lesion located exclusively within the epiphysis of the distal femur. Histology demonstrates mononuclear cells, osteoclast-like giant cells, and fine "chicken-wire" calcifications. What is the diagnosis?