Chondroma

Chondromas are a common benign lesion of hyaline cartilage that affect all age groups. They have limited growth ability and have no aggressive behavior.

The incidence is unclear because most lesions are found incidentally. All age groups are affected, but most commonly diagnosed at the age of 20-50 years old. The incidence in Female and male is equal.

Location

This lesion occurs on surfaces of distal femur, proximal humerus, and proximal femur, it’s called “periosteal juxtacortical chondromas.”

When it’s found in the medullary cavity in the metaphysis of long bones, they are called enchondromas. The most common site for enchondromas are the phalanges of the hand (the most common tumor of the small bones of the hands and feet).

It’s rare in flat bones (pelvis, ribs, scapulae, and vertebrae) and extremely rare in the craniofacial bones.

This tumor may arise from the synovial sheaths of tendons or from the soft tissues adjacent to the tendons in the hand and feet of adults (soft-tissue or synovial chondromas)

See Also: Differential Diagnosis for Bone Lesions

Prognosis

Malignant transformation to chondrosarcoma usually occurs following skeletal maturity. Transformation of a singular enchondromatous lesion is rare, less than 1%. Malignant transformation risk increased with Ollier disease and Maffucci syndrome. These two syndromes are also associated with non-sarcomatous, extraosseous neoplasms, including brain tumors.

Ollier’s disease

Ollier’s disease (also called “Multiple enchondromatosis”) is a rare condition in which many cartilaginous tumors appear in the large and small tubular bones and in the flat bones. Inheritance pattern is sporadic. It is caused by failure of normal endochondral ossification.

These tumors are located in the epiphysis and the metaphysis and shaft. Deformities resulting from Ollier disease include shortening and bowing of the long bones. Shortening is caused by lack of epiphyseal growth, broadening of the metaphysis. Malignancy risk is 25-30 % of patients.

Maffucci Syndrome

Maffucci syndrome is a Multiple enchondromatosis (Ollier’s disease) associated with hemangiomas of the overlying soft tissues. Inheritance pattern is sporadic. Malignancy risk is 23-100 % of patients, patients also have a markedly increased risk of visceral malignancies, such as astrocytomas and gastrointestinal malignancies.

Clinical Evaluation

The patient is usually asymptomatic. It’s frequently discovered incidentally during an unrelated radiographic examination or after a pathological fracture.

When lesions are not causing pain, serial radiographs are obtained to ensure that the lesions are inactive. Radiographs are obtained every 3 to months for 1 to 2 years and then annually as necessary.

Radiology

Radiology appearance is a benign well-defined tumor with intralesional calcification. These calcification is irregular and has been described as “stippled”, “punctate,” or “popcorn.” The lesion size is 1 to 10 cm. Small endosteal erosion or cortical expansion may be present. Small endosteal erosion (<50% width of the cortex) or cortical expansion may be present.

Takigawa proposed a radiographic classification for enchondromas, which has five categories. They include central, eccentric, polycentric, associated, and giant form categories.

CT is the best to evaluate endosteal erosion that could indicate a chondrosarcoma (malignant transformation).

Bone scan: increased uptake due to continual remodeling of the endochondral bone within the lesion.

MRI shows the lesion as lobular and bright on T2 weighted images, with no bone marrow edema or periosteal reaction. It is not necessary for diagnosis.

Histology

Punctate calcifications of the chondroid matrix define the appearance of enchondromas. On examination, the typical lesion is smaller than 3 centimeters. The enchondroma is composed of well-circumscribed nodules of benign hyaline cartilage. There is limited engulfment seen of the adjacent lamellar and cortical bone. The nuclei of the chondrocytes are small and uniformly round with condensed chromatin. Rarely binucleate forms are present.

Foci of endochondral ossification may be present in heavily calcified enchondromas. Syndromes characterized by multiple enchondromas, Ollier’s disease, and Maffucci syndrome exhibit more cellularity and atypia than classic, single enchondromas.

The increased cellularity and atypia make distinguishing enchondroma from chondrosarcoma more difficult. The distinction between benign cartilaginous lesions and atypical cartilaginous tumor/chondrosarcoma grade 1 (ACT/CS1) is difficult. The cartilaginous lesions are typically hypocellular, while ACT/CS1 has a hypercellular appearance. The chondrosarcomas have a higher number of binucleated chondrocytes. Also, they exhibit pleomorphism, cortical destruction, engulfment of the host bone, and irregular cellular distribution.

Differential Diagnoses

Differential Diagnoses include the following:

1. Low-grade chondrosarcoma.
2. Fibrous dysplasia.
3. Bone islands.
4. Bone infarcts.

Chondroma Treatment

Patients with solitary enchondromas usually consists of observation with serial radiographs, if the lesion remains radiographically stable and asymptomatic, no further intervention is indicated.

Operative Treatment

If a lesion grows, or if it becomes symptomatic, extended curettage and bone grafting is indicated.

In case of pathologic fracture, currettage and bone grafting with immobilization is indicated.

Periosteal chondromas are usually excised with a marginal margin.

Prognosis

Patients with benign lesions generally have a good prognosis if they treated appropriately, and most of them remain asymptomatic.

References & More

• Campbel’s Operative Orthopaedics 12th edition Book.
• Millers Review of Orthopaedics -7th Edition Book.
• Biondi NL, Varacallo M. Enchondroma. [Updated 2022 Sep 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536938/
• Silve C, Jüppner H. Ollier disease. Orphanet J Rare Dis. 2006 Sep 22;1:37. doi: 10.1186/1750-1172-1-37. PMID: 16995932; PMCID: PMC1592482.
• Elston JB, Payne WG. Maffucci syndrome. Eplasty. 2014 Apr 25;14:ic11. PMID: 24917896; PMCID: PMC4005419.
• Karaytuğ K, Alpan B, Bayram S, Valiyev N, Bilgiç B, Özger H. Long-term results of different surgical options in the management of solitary enchondroma. ANZ J Surg. 2022 Jul;92(7-8):1809-1813.
• Takigawa K. Chondroma of the bones of the hand. A review of 110 cases. J Bone Joint Surg Am. 1971 Dec;53(8):1591-600. 
• Altay M, Bayrakci K, Yildiz Y, Erekul S, Saglik Y. Secondary chondrosarcoma in cartilage bone tumors: report of 32 patients. J Orthop Sci. 2007 Sep;12(5):415-23.
• Schwartz HS, Zimmerman NB, Simon MA, Wroble RR, Millar EA, Bonfiglio M. The malignant potential of enchondromatosis. J Bone Joint Surg Am. 1987 Feb;69(2):269-74.
• Lewis RJ, Ketcham AS. Maffucci’s syndrome: functional and neoplastic significance. Case report and review of the literature. J Bone Joint Surg Am. 1973 Oct;55(7):1465-79.