10. Pathology and Oncology MCQs

A 14-year-old boy presents with knee pain and a destructive, sunburst periosteal reaction in the distal femur. A biopsy confirms conventional osteosarcoma. Mutation of which tumor suppressor gene, normally responsible for regulating the G1 to S phase cell cycle transition, is most strongly associated with this condition?

A 15-year-old boy presents with a painful mass near his knee. Radiographs reveal a destructive metaphyseal lesion of the distal femur with a 'sunburst' periosteal reaction. Biopsy confirms high-grade, conventional osteosarcoma. Following complete staging, what is the most appropriate initial step in management?

A 68-year-old male presents with a pathologic subtrochanteric femur fracture. Laboratory workup reveals hypercalcemia, renal insufficiency, and anemia. Radiographs show multiple punched-out lytic lesions in the pelvis and skull. What is the most definitive diagnostic test to confirm the suspected underlying systemic condition?

Which of the following genetic alterations is most frequently associated with classic high-grade intramedullary osteosarcoma?

A 14-year-old boy presents with night pain in his right femur. Radiographs reveal a permeative, diaphyseal lytic lesion with an "onion-skin" periosteal reaction. Biopsy confirms small blue cells. Which of the following cytogenetic abnormalities is most characteristic of this diagnosis?

A 4-year-old boy presents with congenital pseudarthrosis of the tibia (CPT). He has a known diagnosis of Neurofibromatosis type 1 (NF1). What is the primary histological characteristic of the pseudarthrosis tissue found at the fracture site in CPT?

A 22-year-old male presents with a slow-growing, deep soft tissue mass in his thigh. Core needle biopsy reveals a biphasic microscopic pattern consisting of spindle cells and epithelial cells. Cytogenetic testing demonstrates a t(X;18) chromosomal translocation. Which of the following is the most likely diagnosis?

A 16-year-old male complains of severe mid-tibial pain that is characteristically worse at night and awakens him from sleep. The pain dramatically resolves within 30 minutes of taking ibuprofen. Radiographs demonstrate a 7 mm radiolucent nidus surrounded by intense reactive cortical sclerosis. The profound pain relief provided by NSAIDs is primarily mediated by the inhibition of which substance highly produced by the nidus?

In a 16-year-old patient diagnosed with high-grade conventional osteosarcoma of the distal femur, what is the single most important prognostic factor for long-term overall survival following neoadjuvant chemotherapy and surgical resection?

A 14-year-old boy presents with pain and swelling in the diaphysis of his left femur. Radiographs demonstrate a permeative destructive lesion with a prominent 'onion skin' periosteal reaction. Biopsy reveals small, round, blue cells. Which specific chromosomal translocation is most characteristically associated with this patient's tumor?

A 15-year-old girl complains of severe, progressively worsening back pain that is predominantly nocturnal and relieved dramatically by non-steroidal anti-inflammatory drugs. Examination reveals a painful structural scoliotic curve. Imaging demonstrates a small radiolucent nidus with surrounding sclerosis in the posterior elements of L3. Which of the following statements is true regarding her scoliosis?

A 25-year-old male presents with chronic dull aching pain in his anterior leg. Radiographs reveal a multi-loculated, expansile, 'soap-bubble' osteolytic lesion in the anterior cortex of the tibial diaphysis. Biopsy shows nests of basaloid cells with peripheral palisading in a fibrous stroma. Which of the following conditions is most closely related histogenetically to this tumor?

A 60-year-old male is scheduled for prophylactic internal fixation of an impending pathologic subtrochanteric femur fracture. His primary malignancy is known to be renal cell carcinoma. Which of the following preoperative interventions is most highly recommended to reduce perioperative morbidity?

A 14-year-old male presents with a permeative diaphyseal lesion of the femur with a significant soft tissue mass. A biopsy confirms Ewing sarcoma. Which chromosomal translocation is most characteristically associated with this diagnosis?

Which of the following cytogenetic abnormalities is most characteristically associated with primary Aneurysmal Bone Cysts (ABCs)?

A 9-year-old boy falls and fractures his proximal humerus. Radiographs reveal a central, purely lytic lesion in the metaphysis with a piece of cortical bone resting dependently within the cavity ('fallen leaf' sign). If aspirated, the fluid within this cyst is most likely to contain high levels of which substance?

An 8-year-old boy presents with a symptomatic unicameral bone cyst (UBC) in the proximal humerus. Radiographs show a 'fallen leaf' sign. What is the most widely accepted initial invasive treatment for an active, symptomatic UBC?

A 15-year-old boy presents with a painful mass in his distal femur. Biopsy confirms osteosarcoma. Which of the following genetic syndromes is most commonly associated with a significantly increased risk of developing this specific malignancy?

A 55-year-old male presents with deep, aching thigh pain. Radiographs reveal a lytic lesion in the proximal femur with 'popcorn' calcification and endosteal scalloping greater than two-thirds of the cortical thickness. What is the most appropriate next step in management?