LEC 5 neoplasm of bone and cartilage

• Osteoid osteoma:

  • More common in males than females
  • Typically affects individuals in the second and third decades of life
  • Believed to be a benign bone-forming tumor arising from osteoblasts
  • Characterized by a central nidus of osteoid tissue surrounded by reactive bone formation
  • Nidus is typically less than 1.5 cm in size and may exhibit central calcification
  • Patients commonly present with localized bone pain that worsens at night and is relieved by NSAIDs
  • Complications include bone deformities, joint stiffness, and functional impairment, as well as pathological fractures
• • Complications include nerve impingement, fracture of the stalk, skeletal deformities, and malignant transformation into chondrosarcoma in rare cases
• Osteochondroma:

  • Often sporadic but can also occur in individuals with multiple hereditary exostoses (MHE)
  • Considered developmental anomalies arising from abnormal growth of the growth plate cartilage
  • Develop from the growth plate cartilage and consist of a bony stalk capped with cartilage
  • Appear as bony projections covered with a cartilaginous cap, typically pedunculated or sessile
  • Usually asymptomatic but can present as painless masses
• Aneurysmal bone cyst:

  • More common in children and young adults
  • Believed to result from vascular malformations or trauma to the bone
  • Characterized by blood-filled cystic spaces separated by fibrous septa and surrounded by reactive bone
  • Imaging shows expansile lytic lesions with a "blowout" appearance
  • Patients may experience localized pain, swelling, and limited range of motion
  • Complications include bone deformities, pathological fractures, recurrence after treatment, and in rare cases, malignant transformation
• Giant cell tumour:

  • Most commonly affects individuals between the ages of 20 and 40, with a slight female predilection
  • Arise from the mesenchymal stromal cells in bone
  • Characterized by multinucleated giant cells, stromal cells, and mononuclear cells
  • Appear as eccentric, lytic lesions in the epiphysis of long bones, commonly around the knee joint
  • Patients may experience localized pain, swelling, and limited range of motion
  • Complications include local recurrence after surgical resection, joint dysfunction, pulmonary metastases, and malignant transformation to sarcoma in rare cases
• Chondroma:

  • Benign tumors of hyaline cartilage
  • Can occur sporadically or as part of syndromes like Ollier disease and Maffucci syndrome
  • Arise from abnormal cartilage growth or differentiation
  • Develop from the proliferation of chondrocytes within the cartilage matrix
  • Appear as solitary nodules of hyaline cartilage within the medullary cavity or on the cortical surface
  • Patients may present with localized pain, swelling, or a palpable mass
• • Complications include skeletal deformities, pathological fractures, and an increased risk of malignant transformation to chondrosarcoma in cases of multiple lesions
• • Complications include local recurrence, metastasis, resistance to chemotherapy, and potential secondary malignancies
• Osteosarcoma:

  • Risk factors include bone infarcts, Paget disease, post-radiation therapy, chronic osteomyelitis, presence of metal prostheses, and genetic syndromes like retinoblastoma and Li-Fraumeni syndrome
  • Primary malignant bone tumor arising from primitive bone-forming mesenchymal cells
  • Develops from genetic mutations disrupting normal bone cell differentiation
  • Presents as a destructive mass with areas of necrosis, hemorrhage, and new bone formation
  • Patients may experience localized pain, swelling, and limited range of motion
• • Complications include local recurrence, metastasis, resistance to chemotherapy, and dedifferentiation leading to a more aggressive clinical course
• Chondrosarcoma:

  • Risk factors include previous radiation exposure, hereditary multiple exostoses (HME), and underlying bone conditions like Ollier disease and Maffucci syndrome
  • Malignant tumor derived from transformed cartilage-producing cells (chondrocytes) within the bone
  • Arises from genetic mutations leading to uncontrolled growth and proliferation of chondrocytes
  • Presents as a lobulated mass with areas of calcification and cartilaginous matrix
  • Patients may present with localized pain, swelling, and a palpable mass