Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Radiology description | Radiology images | Treatment | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Pernick N. Enchondroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonechondromaenchondroma.html. Accessed February 8th, 2023.
Definition / general
- Usually asymptomatic or pain due to pathologic fracture
- May be due to displaced growth plate
- 70% solitary; 30% multiple
- Multiple enchondromas: may produce severe deformities; associated with chondrosarcomatous transformation
Terminology
- Enchondroma protuberans: rare, exaggeratedly eccentric enchondroma resembling osteochondroma radiologically (Hum Pathol 1982;13:734)
- Maffuci syndrome: multiple enchondromas and soft tissue hemangiomas; also ovarian carcinoma, brain gliomas
- Ollier disease: nonhereditary disease of multiple enchondromas of long bones and flat bones (up to 50% of skeleton) with associated skeletal deformities, histologic features of low grade chondrosarcoma should be ignored if radiographically benign; most lesions regress when skeleton matures; often ovarian sex cord tumors
Epidemiology
- Age 20 - 49 years, M = F
Sites
- Small bones of hands and feet (rare in thumb or ribs)
Radiology description
- Thinning but preservation of cortex, O ring sign, no penetration into soft tissue, pathologic fractures common
- Long bones: well circumscribed tumor of metaphysis or diaphysis with flecks of calcification; doesn’t invade the cortex
Radiology images
Treatment
- Excision, may recur if incompletely excised
- Often no treatment recommended
Case reports
- 34 year old man with Ollier disease (Hum Pathol 2000;31:1299)
- 53 year old man with multiple foci of chondrosarcomatous transformation (Hum Pathol 1984;15:91)
- Patient with tenosynovial chondroma of hand (Hum Pathol 1978;9:476)
Gross description
- Well circumscribed, pale blue, solid, resembles cartilage but without myxoid change
Gross images
Microscopic (histologic) description
- Lobules of hyaline cartilage encased by bone and covered by perichondrium (fibrous tissue)
- Resembles low grade chondrosarcoma due to hypercellularity, binucleation, myxoid change but radiographically is benign
- Calcification, endochondral ossification
- Necrosis common in benign lesions due to avascular cartilage
- Tongues of bone extend into cartilage (versus sharp interface at growth plate)
- More atypia present with Ollier disease and Maffuci syndrome
- Long bones: hypocellular, few binucleated cells, may be multifocal but does not infiltrate marrow; no myxoid change
Microscopic (histologic) images
Differential diagnosis
- Epiphyseal dysplasia:
- In babies, affects multiple joints
- Low grade chondrosarcoma:
- Breaks through or erodes cortex, marked myxoid change, large tumors occupy marrow space and entrap bony trabeculae