Enchondroma question

Enchondroma

Introduction
* A benign chondrogenic lesion caused by an abnormality of chondroblast function in the physis
  • chondroblasts escape the physis and proliferate in metaphysis
  • 2nd most common benign cartilage lesion (osteochondroma is most common)
  • Age & location
    • age range is 10-60 years
    • occurs in medullary cavity in diaphysis or metaphysis
    • hand is most common location (60%)
      • presentation as pathological fractures common
    • other locations include the femur (20%) and proximal humerus (10%)
  • Include
    • solitary enchondroma
      • 1% chance of malignant transformation (chondrosarcoma)
    • Ollier’s disease (multipe enchondromatosis)
      • no genetic predisposition has been identified
      • multiple enchondromas in long bone diaphysis
      • 10-30% chance of malignant transformation into chondrosarcoma
        • however associated with high rate of both skeletal and non-skeletal malignancies
      • involved bones are dysplastic
    • Maffucci’s syndrome
      • no genetic predisposition has been identified
      • multiple enchondromas and soft-tissue angiomas
      • 100% chance of malignant transformation into chondrosarcoma
      • increased risk of visceral malignancies (astrocytoma, GI malignancy)|

Symptoms

  • Presentation

    • most are asymptomatic
    • often present as pathologic fx of the hand but asymptomatic in foot
  • Physical exam

    • enchondroma may disrupt the growth plate and lead to shortening and angular deformities
      Imaging
  • Radiograph

    • “pop-corn” mineralization (calcification), stippled ringsin diaphyseal or metaphyseal medullary cavity
    • occasionally may have purly lytic appearance (especially in hand) \ 16x11
  • Bone scan may be helpful and is usually minimally warm

  • MRI may show steak of cartilage or “sled runner tracks”
    Histology

  • Classic characteristics include

    • hypocellular with bland hyaline cartilage (blue balls of cartilage) \ 16x11 \ 16x11
    • lesions in hand are more hypercellular and even display some worrisome histologic characteristics
    • small chondroid cells in lacunar spaces
      Differential
  • Must differentiate from a bone infarct (“smoke-up-chimney” appearance)
    Treatment

  • Nonoperative

    • observation
      • treatment for most enchondromas
      • watch with serial xrays for interval growth (obtain xrays at 3 months and 1 year from time of presentation)
  • Operative

    • curettage and bone grafting
      • indications
        • lesion that shows any change on serial xrays
        • hand fractures after fracture has first been allowed to heal with imobilization
  • Ollier’s disease and Maffucci’s

    • treat deformity with diaphysectomy
    • watch lesions carefully for malignant transformation

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