10. Pathology and Oncology MCQs

A 50-year-old woman is found to have an expansive, lytic lesion in her distal femur.

Serum calcium is 11.5 mg/dL (Normal: 8.5-10.5) and PTH is significantly elevated. Biopsy reveals highly vascular fibroblastic stroma containing numerous multinucleated giant cells and hemosiderin. What is the most appropriate definitive management for the bone lesion?

A 65-year-old man undergoes a biopsy for an expansile diaphyseal tibial lesion. Pathology shows a chaotic pattern of woven and lamellar bone with prominent and irregular cement lines. Based on this histological description, what is the most likely diagnosis?

A 15-year-old boy presents with progressive distal thigh pain. Radiographs reveal a mixed lytic and sclerotic lesion in the distal femoral metaphysis with a 'sunburst' periosteal reaction and Codman's triangle. A biopsy is performed. Which of the following histological findings is required to confirm the most likely diagnosis?

A 15-year-old male is diagnosed with conventional osteosarcoma of the distal femur. Which of the following tumor suppressor gene mutations is most strongly associated with the pathogenesis of this primary bone malignancy?

A 15-year-old male is diagnosed with osteosarcoma of the distal femur, characterized radiographically by a 'sunburst' pattern. Which of the following genetic mutations is most strongly associated with the pathogenesis of this primary bone tumor?

A 15-year-old male presents with a painful, enlarging mass in his distal femur. Radiographs demonstrate a destructive metaphyseal lesion with a 'sunburst' periosteal reaction. Biopsy confirms osteosarcoma. Mutations in which of the following pairs of tumor suppressor genes are most strongly implicated in the pathogenesis of this patient's primary bone malignancy?

An 11-year-old boy presents with a painful mass in his diaphyseal femur. Radiographs show a permeative, destructive lesion with an "onion skin" periosteal reaction. Cytogenetic analysis of a biopsy specimen will most likely reveal which of the following genetic translocations?

A 14-year-old boy presents with a permeative diaphyseal lesion in his femur with an associated large soft tissue mass. Biopsy reveals sheets of uniform, small round blue cells. Which of the following cytogenetic abnormalities is most closely associated with this diagnosis?

A 15-year-old girl presents with knee pain and a destructive, permeative diaphyseal lesion in her femur with an associated "onion skin" periosteal reaction. Biopsy confirms small round blue cells. Which of the following chromosomal translocations is most characteristic of this pathology?

Synovial chondromatosis is a benign nodular condition characterized by which of the following pathophysiologic mechanisms?

A 55-year-old woman presents with a deep thigh mass. MRI reveals a large, predominantly lipomatous tumor with thickened, nodular septa. Biopsy shows mature adipocytes with focal hyperchromatic, atypical stromal cells. Which genetic alteration is most specific for this diagnosis?

Which of the following best describes the fundamental pathogenesis underlying primary synovial chondromatosis?

Multiple Hereditary Exostoses (MHE) is characterized by multiple osteochondromas throughout the skeleton. Mutations in the EXT1 and EXT2 genes are causative. What is the primary molecular function impaired by these mutations?

A 55-year-old male presents with a large, slow-growing, deep soft tissue mass in his posterior thigh. Histopathology demonstrates mature adipocytes with focal variation in cell size and hyperchromatic stromal cells.

Which molecular finding specifically differentiates an Atypical Lipomatous Tumor (ALT) from a benign lipoma?

An 18-year-old male with a known solitary osteochondroma of the proximal tibia presents with increasing localized pain and recent growth of the lesion over the past 6 months. MRI reveals a cartilage cap measuring 2.8 cm in thickness.

What is the most likely diagnosis?

Histologically, an Atypical Lipomatous Tumor (ALT) and a Well-Differentiated Liposarcoma (WDLPS) are identical. What is the primary criterion used to differentiate these two entities in nomenclature?

A 40-year-old male with a history of recurrent primary synovial chondromatosis of the hip presents with rapid clinical deterioration, severe pain, and extensive bony destruction on imaging.

What is the most feared complication in this setting?

An osteochondroma is defined as a cartilage-capped exostosis.

Which of the following imaging features is pathognomonic and strictly required for the diagnosis of an osteochondroma?

On a standard radiograph, the presence of multiple, uniform-sized, spherical calcified loose bodies within the joint capsule of the knee strongly suggests which of the following diagnoses?

A 35-year-old male presents with chronic knee pain, swelling, and mechanical catching. Radiographs show multiple intra-articular calcified bodies of uniform size.

Which of the following is the underlying pathophysiology of this condition?