Endogenous chondrosarcoma can occur in the bone, also known as central, or on the bone surface, also known as borderline (periosteal chondrosarcoma), as a single lesion, or as multiple lesions (endogenous chondrosarcoma), and chondrosarcoma can also be associated with soft tissue hemangioma (Maffucci syndrome). Clinical manifestations: Endogenous chondromas are solitary endogenous chondromas that are tumors in the medullary cavity and are composed of hyaline cartilage lobules Onset is often between 30 and 40 years of age, with equal proportions of men and women. Patients usually present to the clinic with no specific symptoms or with painless swelling. If there is a pathologic fracture, pain may be present and the tumor is often detected on radiographs. The presence of painful symptoms in the long tubular pelvis and scapular girdle should be noted for malignancy. Generally, there are no systemic symptoms. Preferred site: Generally speaking, the bones invaded by endogenous chondrosarcoma are rarely invaded by chondrosarcoma. About 40% to 65% of single endophytic chondrosarcomas occur in the hand and less frequently in the foot. Within the hand, the proximal phalanges are the best site of occurrence, accounting for approximately 40% to 50% of cases. This is followed by the metacarpals (about 15%-30%), the middle phalanges accounting for 20%-30%, and rarely located in the terminal phalanges (about 5%-15%). The incidence of each finger is most frequent in the middle finger, followed by the ring and little finger, and again in the thumb, which is the least common in the carpal bone (less than 2%). The incidence of endogenous chondrosarcoma is about 25% in long tubular bones and is more frequent in the upper extremities than in the lower extremities. Typical sites are the humerus femur and tibia. The iliac bone is the preferred site for chondrosarcoma, while only 3% of endogenous chondrosarcomas develop in the iliac bone. The skull, facial bones, patella, heel bone, sternum, scapula, ulna, and spine are rare sites. Endogenous chondrosarcomas that occur in long tubular bones are usually located in the center of the epiphysis. When the epiphysis is closed, the tumor may be pushed toward the diaphysis or epiphysis and in the hand and foot, it is located in the center of the short tubular diaphysis. Diagnosis: In adolescent patients, the tumor is found in the hand and foot bones, the tumor grows slowly and can last for several years or ten years, local mass, pain is not obvious. Differential diagnosis: 1. Bone cysts occur mostly in adolescents, most commonly in the humerus and femur, located in the epiphysis, connected to or separated from the epiphyseal plate, often with pathologic fractures X-ray is also limited osteolytic destruction, but more transparent. The cystic cavity is hollow and contains a small amount of fluid. The cystic wall is fibrous tissue and new bone tissue, and multinucleated giant cells are occasionally seen microscopically. 2, abnormal proliferation of fibers Most often occurs in the age of 10 to 30 years, the femur tibia, ribs are more common. The symptoms are not obvious, often combined with pathological fractures. x-ray examination is limited osteolytic destruction, the lesion is frosted glass-like. On pathological examination, the tumor tissue is grayish white, hard and tough like rubber, with gravel-like material inside the fire canister network. Microscopically, it is fibrous tissue and saprophytic bone Treatment If the diagnosis of endogenous chondrosarcoma is established, the lesion should be scraped and autologous bone grafting surgery is more effective, special attention should be paid to not transplanting cartilage blocks into soft tissue during surgery. If a second surgery is required, the tissue that has passed through the healthy search in the 1st approach should be removed together. If there is a malignant change or recurrence a local whole block excision may be used. Amputation may be done if necessary.