Chondrosarcoma overview

# Overview
Chondrosarcoma is the second most common malignant primary tumor of bone. it is most frequently diagnosed in patients in their 4th and 5th decades of life.Men are slightly more affected with chondrosarcoma than women. There is no racial predilection to chondrosarcoma. Jaffe and Lichtenstein first described chondrosarcoma in 1948. Chondrosarcoma may be classified based on histological findings and location. The exact pathogenesis of chondrosarcoama is not fully understood. Multiple genes have been implicated in pathogenesis of chondrosarcoma. Cytogenetic analysis of chondrosarcomas revealed that structural abnormalities of chromosomes 1, 6, 9, 12 and 15 and numerical abnormalities of chromosomes 5, 7, 8 and 18 are most frequent associated. Anomalies associated with chromosome 9(9p12-22) are more commonly seen in central chondrosarcomas. Germline mutations in the exostosin (EXT1 or EXT2) genes, TP53 or pRb pathway, isocitrate dehydrogenase-1 and isocitrate dehydrogenase 2 genes and gene encoding the receptor for parathyroid have been implicated. On gross pathology, greyish-white lobulated mass, necrosis, calcification, and mucoid degeneration are characteristic findings of chondrosarcoma. On microscopic histopathological analysis abnormal cartilage, increased cellularity, and nuclear atypia are characteristic findings of chondrosarcoma. Chondrosarcoma may be divided into three grades based on cancer cells morphology under microscope and growth rate of tumor. There are no established causes for chondrosarcoma. Common risk factors in the development of chondrosarcoma are benign cartilage tumors such as enchondromas, osteochondromas, multiple exostoses, Ollier's disease, and Maffucci's syndrome. Chondrosarcoma must be differentiated from other diseases such as chondroma, enchondroma, osteochondroma, and osteosarcoma. Complications that can develop as a result of chondrosarcoma are metastasis and recurrence. The prognosis of chondrosarcoma correlates with the grade and stage of the lesion at the time of diagnosis. Chondrosarcoma is associated with a 5 year survival rate of 70%. The presence of grade 3 lesions are associated with a particularly poor prognosis. Biopsy is the gold standard test for the diagnosis of chondrosarcoma. Open biopsy is carried out for chondrosarcoma. The tumor is then staged based on Enneking system for chondrosarcoma. The most common symptoms of chondrosarcoma include pain and swelling in the area of tumor. Patients with chondrosarcoma usually appear lethargic and emaciated. Physical examination of patients with chondrosarcoma is usually remarkable for palpable mass, tenderness and decreased range of motion. On x-ray, chondrosarcoma is characterized by lytic lesion, intralesional calcification, endosteal scalloping, and cortical remodeling. On CT scan chondrosarcoma is characterized by matrix calcification, endosteal calcification, cortical breach, and heterogenous contrast enhancement. On MRI, chondrosarcoma is characterized by low to intermediate signal on T1, very high intensity in calcified portions on T2, and moderate to intense contrast enhancement on T1 contrast. Bone scan shows very hot uptake in all grades of chondrosarcoma. Chemotherapy and radiotherapy are indicated for chondrosarcoma as adjuvant therapy or palliative treatment in surgically inaccessible areas. Surgery is the mainstay of treatment for chondrosarcoma. Adjunctive chemotherapy and radiation may be required. Recurrence rate depends on the grade of chondrosarcoma.

# Historical Perspective
In 1948, Jaffe and Lichtenstein described chondrosarcoma for the first time.

# Classification
Chondrosarcoma may be classified based on histological findings and location.

# Pathophysiology
The exact pathogenesis of chondrosarcoama is not fully understood. Multiple genes have been implicated in pathogenesis of chondrosarcoma. Cytogenetic analysis of chondrosarcomas revealed that structural abnormalities of chromosomes 1, 6, 9, 12 and 15 and  numerical abnormalities of chromosomes 5, 7, 8 and 18 are most frequent associated. Anomalies associated with chromosome 9(9p12-22) are more commonly seen in central chondrosarcomas. Germline mutations in the exostosin (EXT1 or EXT2) genes,  TP53 or pRb pathway,  isocitrate dehydrogenase-1 and isocitrate dehydrogenase- 2 genes and gene encoding the receptor for parathyroid have been implicated. On gross pathology, greyish-white lobulated mass, necrosis, calcification, and mucoid degeneration are characteristic findings of chondrosarcoma. On microscopic histopathological analysis abnormal cartilage, increased cellularity, and nuclear atypia are characteristic findings of chondrosarcoma. Chondrosarcoma may be divided into three grades based on cancer cells morphology under microscope and growth rate of tumor.

# Causes
The cause of chondrosarcoma has not been identified.

# Differentiating chondrosarcoma from other Diseases
Chondrosarcoma must be differentiated from other diseases such as chondroma, enchondroma, osteochondroma, and osteosarcoma.

# Epidemiology and Demographics
Chondrosarcoma is the second most common malignant primary tumor of bone. It is most frequently diagnosed in patients in their 4th and 5th decades of life. Men are slightly more affected by chondrosarcoma than women. There is no racial predilection to chondrosarcoma.

# Risk Factors
Common risk factors in the development of chondrosarcoma are benign cartilage tumors such as enchondromas, osteochondromas, multiple exostoses, Ollier's disease, and Maffucci's syndrome.

# Natural History, Complications, and Prognosis
Complications that can develop as a result of chondrosarcoma are metastasis and recurrence. The prognosis of chondrosarcoma correlates with the grade and stage of the lesion at the time of diagnosis. Chondrosarcoma is associated with a 5 year survival rate of 70%. The presence of grade 3 lesions are associated with a particularly poor prognosis.

# Diagnostic Study of Choice
Biopsy is the gold standard test for the diagnosis of chondrosarcoma. Open biopsy is carried out for chondrosarcoma. The tumor is then staged based on Enneking system for chondrosarcoma.

# History and Symptoms
The most common symptoms of chondrosarcoma include pain and swelling in the area of tumor.

# Physical Examination
Patients with chondrosarcoma usually appear lethargic and emaciated. Physical examination of patients with chondrosarcoma is usually remarkable for palpable mass, tenderness and decreased range of motion.

# Laboratory findings
There are no specific laboratory tests for the diagnosis of chondrosarcoma.

# Electrocardiogram
There are no ECG findings associated with chondrosarcoma.

# X Ray
On x-ray, chondrosarcoma is characterized by lytic lesion, intralesional calcification, endosteal scalloping, and cortical remodeling.

# Echocardiography/Ultrasound
There are no echocardiography/ultrasound findings associated with Chondrosarcoma.

# CT
On CT scan chondrosarcoma is characterized by matrix calcification, endosteal calcification, cortical breach, and heterogenous contrast enhancement.

# MRI
On MRI, chondrosarcoma is characterized by low to intermediate signal on T1, very high intensity in calcified portions on T2, and moderate to intense contrast enhancement on T1 contrast.

# Other imaging findings
Bone scan shows very hot uptake in all grades of chondrosarcoma.

# Other Diagnostic Studies
There are no other diagnostic studies associated with chondrosarcoma.

# Medical Therapy
Chemotherapy and radiotherapy are indicated for chondrosarcoma as adjuvant therapy or palliative treatment in surgically inaccessible areas. Surgery is the mainstay of treatment for chondrosarcoma.

# Surgery
Surgery is the mainstay of treatment for chondrosarcoma. Adjunctive chemotherapy and radiation may be required. Recurrence rate depends on the grade of chondrosarcoma.

# Primary prevention
There are no established measures for the primary prevention of chondrosarcoma.

# Secondary prevention
There are no established measures for the secondary prevention of chondrosarcoma.