Describe Enchondroma in detail.
Definition
Enchondroma is a common benign tumour of mature hyaline cartilage arising within the medullary cavity of a bone. It most often affects the small tubular bones of the hands and feet and the long bones, and is usually solitary.
Clinical Features
Most enchondromas are asymptomatic and found incidentally, or they present as a pathological fracture through a weakened phalanx. Multiple enchondromas occur in Ollier’s disease, and multiple enchondromas with soft-tissue haemangiomas in Maffucci’s syndrome — both carry an increased risk of malignant change to chondrosarcoma.
Investigations & Management
Radiographs show a well-defined lucent medullary lesion, often with stippled or ‘popcorn’ calcification of the cartilage matrix and endosteal scalloping. Asymptomatic lesions are observed; a symptomatic lesion or pathological fracture is treated by curettage and bone grafting. Features suggesting malignant transformation (pain without fracture, cortical destruction, a soft-tissue mass, growth in an adult) warrant biopsy.
DANGER / REMEMBER
In an adult, a cartilage lesion that becomes painful (without fracture), enlarges or destroys cortex may be a chondrosarcoma rather than a benign enchondroma — the distinction can be difficult and needs specialist assessment.
Pathology & Syndromes
The lesion is composed of lobules of mature hyaline cartilage within the medulla, separated by normal marrow. It is usually solitary, but two non-hereditary syndromes are important: Ollier’s disease (multiple enchondromatosis, often asymmetrical, with deformity and shortening) and Maffucci’s syndrome (multiple enchondromas plus soft-tissue haemangiomas). Both carry a substantially increased risk of malignant transformation to chondrosarcoma, so patients need long-term surveillance.
CLINICAL PEARL
A phalangeal lucent lesion with popcorn calcification that presents as a pathological fracture in a young adult is very likely a benign enchondroma; multiple lesions should prompt thought of Ollier’s or Maffucci’s and their malignant potential.
Multiple enchondromas — Ollier disease, Maffucci syndrome.
KEY POINT
Key points TO remember
- Benign hyaline-cartilage tumour within the medulla; hands/feet and long bones.
- Often asymptomatic or presents as a pathological fracture of a phalanx.
- X-ray: lucent lesion with popcorn calcification & endosteal scalloping.
- Observe if asymptomatic; curette + graft if symptomatic; Ollier/Maffucci carry malignant risk.
EXAM TIP
Sources: Maheshwari's Essential Orthopaedics; Apley & Solomon's System of Orthopaedics and Trauma; AO Principles of Fracture Management.
All questions in Bone Tumours
- Q1Define Classification & Approach to a Bone Tumour. Describe its clinical features and management. ★
- Q2Define Osteosarcoma. Describe its clinical features, investigations, management and prognosis. ★
- Q3Define Ewing’s Sarcoma. Describe its clinical features, investigations, management and prognosis. ★
- Q4Giant Cell Tumour ★
- Q5Define Metastatic Bone Disease. Describe its clinical features, investigations, management and prognosis. ★
- SN1Define Osteochondroma. Describe its clinical features and management.
- SN2Define Osteoid Osteoma. Describe its clinical features and diagnosis. ★
- SN3Describe Enchondroma in detail.
- SN4Describe Periosteal Reactions & Codman’s Triangle in detail.
- SN5Define Multiple Myeloma. Describe its clinical features, investigations and management. ★
- SN6Describe Simple & Aneurysmal Bone Cysts in detail.
- SN7Define Pathological Fracture. Describe its causes and management. ★