Chondroma overview

# Overview
Juxtacortical chondroma was first discovered by Lichtenstein and Hall in 1952. The term juxtacortical chondroma was first coined by Jaffe in 1956. Chondroma may be classified according to location of the outgrowth into 3 groups that include enchondrom, periosteal chondroma and synovial chondroma. Enchondromas arise from rests of growth plate cartilage or chondrocytes that are normally involved in the production and maintainence of the cartilaginous matrix, which consists mainly of collagen and proteoglycans. Genes involved in the pathogenesis of enchondromas and periostal chondromas include isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2). On gross pathology, small (usually less than 3 cm), translucent, grey blue, nodular lesions with occasional calcifications are characteristic findings of chondromas. Enchondromas may be single or multiple. Multiple enchondromas are associated Maffucci syndrome, Ollier disease and metachondromatosis. The cause of chondromas has not been identified. However, enchondroma is believed to occur either as an overgrowth of the cartilage that lines the ends of the bones, or as a persistent growth of original embryonic cartilage.The incidence of osteochondromas is approximately 30,000 per 100,000 of all cartilage tumors and 2,000 per 100,000 of all bone tumors.The prevalence of enchondromas is approximately 12,000 - 24,000 per 100,000 individuals of benign bone tumors and 3000 - 10,000 of all bone tumors. Patients of all age groups may develop enchondromas. The incidence of enchondroma peaks in the third and fourth decades of life. Enchondroma affects men and women equally. Chondroma is usually diagnosed incidentally. Common complications of chondroma include malignant transformation into a low grade growth disturbance, pathologic fracture, especially in short tubular and recurrence. Benign chondromas have a good prognosis with aprropriate treatment. The majority of patients with enchondroma are asymptomatic. Less common symptoms of enchondroma may include pain, enlargement of the affected digits, and slowing of affected bone growth and asymmetrical bone deformities. There are no diagnostic lab findings associated with chondroma. Findings on an x-ray suggestive of chondroma include well-defined or sclerotic border, sharp zone of transition, confinement by natural barriers, lack of destruction of the cortex and lack of extension into the soft tissue. Findings on CT scan suggestive of enchondroma include sharply defined scalloped margins, expansion of the overlying cortex may be present, no periosteal reaction and soft tissue mass. Findings on MRI suggestive of chondroma include well circumscribed, lobulated mass replacing the marrow for enchondroma, lobulated soft tissue lesion that is abutting the cortex and evidence of pressure erosion on neighboring bone, with no evidence of medullary bone or soft tissue edema for periostal chondroma for periostal chondroma. Surgery is not the first-line treatment option for patients with asymptomatic and benign chondroma. Surgery is usually reserved for patients with either malignant transformation and pathological fracture.

# Historical Perspective
Juxtacortical chondroma was first discovered by Lichtenstein and Hall in 1952. The term juxtacortical chondroma was first coined by Jaffe in 1956.

# Classification
Chondroma may be classified according to location of the outgrowth into 3 groups that include enchondrom, periosteal chondroma and synovial chondroma.

# Pathophysiology
Enchondromas arise from rests of growth plate cartilage or chondrocytes that are normally involved in the production and maintainence of the cartilaginous matrix, which consists mainly of collagen and proteoglycans. Genes involved in the pathogenesis of enchondromas and periostal chondromas include isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2). On gross pathology, small (usually less than 3 cm), translucent, grey blue, nodular lesions with occasional calcifications are characteristic findings of chondromas. Enchondromas may be single or multiple. Multiple enchondromas are associated Maffucci syndrome, Ollier disease and metachondromatosis.

# Causes
The cause of chondromas has not been identified. However, enchondroma is believed to occur either as an overgrowth of the cartilage that lines the ends of the bones, or as a persistent growth of original embryonic cartilage.

# Epidemiology and Demographics
The incidence of osteochondromas is approximately 30,000 per 100,000 of all cartilage tumors and 2,000 per 100,000 of all bone tumors.The prevalence of enchondromas is approximately 12,000 - 24,000 per 100,000 individuals of benign bone tumors and 3000 -10,000 of all bone tumors. Patients of all age groups may develop enchondromas. The incidence of enchondroma peaks in the third and fourth decades of life. Enchondroma affects men and women equally.

# Risk Factors
There are no established risk factors for chondromas.

# Screening
There is insufficient evidence to recommend routine screening for chondromas.

# Differential Diagnosis
Enchondroma must be differentiated from low-grade chondrosarcoma, fibrocartilaginous dysplasia, bone islands and bone infarcts. Periosteal chondroma must be differentiated from periosteal chondrosarcoma and periosteal osteosarcoma.

# Natural History, Complications and Prognosis
Chondroma is usually diagnosed incidentally. Common complications of chondroma include malignant transformation into a low grade growth disturbance, pathologic fracture, especially in short tubular and recurrence. Benign chondromas have a good prognosis with aprropriate treatment.

# History and Symptoms
The majority of patients with enchondroma are asymptomatic. Less common symptoms of enchondroma may include pain, enlargement of the affected digits, and slowing of affected bone growth and asymmetrical bone deformities.

# Physical Examination
Patients with chondroma usually appear well. Physical examination of patients with enchondroma is usually unremarkable.

# Laboratory Findings
There are no diagnostic lab findings associated with chondroma.

# Electrocardiogram
There are no electrocardiogram findings associated with chondroma.

# X Ray Findings
Findings on an x-ray suggestive of chondroma include well-defined or sclerotic border, sharp zone of transition, confinement by natural barriers, lack of destruction of the cortex and lack of extension into the soft tissue.

# CT
Findings on CT scan suggestive of enchondroma include sharply defined scalloped margins, expansion of the overlying cortex may be present, no periosteal reaction and soft tissue mass.

# MRI
Findings on MRI suggestive of chondroma include well circumscribed, lobulated mass replacing the marrow for enchondroma, lobulated soft tissue lesion that is abutting the cortex and evidence of pressure erosion on neighboring bone, with no evidence of medullary bone or soft tissue edema for periostal chondroma for periostal chondroma.

# Echocardiography or Ultrasound
There are no echocardiography or ultrasound findings associated with chondroma.

# Other imaging studies
Other imaging studies for enchondroma includes radionuclide bone scan.

# Medical Therapy
There is no medical therapy for chondromas; the mainstay of therapy is surgery.

# Surgery
Surgery is not the first-line treatment option for patients with asymptomatic and benign chondroma. Surgery is usually reserved for patients with either malignant transformation and pathological fracture.

# Primary Prevention
There is no established method for primary prevention of chondroma.

# Secondary Prevention
There is no established method for secondary prevention of chondroma.