Osteochondroma and Benign Tumors

The histological image provided shows a lesion characterized by a cartilaginous cap overlying mature trabecular bone that is continuous with the underlying medullary cavity. Which of the following is the most likely diagnosis?

A 16-year-old boy presents with a painless bony lump over the distal femur that has been gradually enlarging over the past 2 years. On examination, a firm, immobile, bony hard mass is palpable over the posterolateral aspect of the distal femur. Plain radiographs show a sessile bony projection with a cartilage cap arising from the metaphyseal region. The lesion is oriented away from the joint. What is the most likely diagnosis?

A 22-year-old woman presents with multiple bony lumps over both knees, shoulders, and pelvis that have been present since childhood and continue to grow slowly. Family history is significant for similar bony tumors in her mother and maternal grandfather. Plain radiographs show multiple sessile and pedunculated bony projections with cartilage caps at the metaphyseal regions of long bones. Genetic testing reveals a mutation in the EXT1 gene. What is the most appropriate management for this patient?