- Aneurysmal bone cyst
Name = PAGENAME
Caption = The ABC is located on the left, on the fifth metatarsal. Notice that the bone appears to be missing on the x-ray.
ICD10 = ICD10|M|85|5|m|80
ICD9 = ICD9|733.22
eMedicineSubj = radio
eMedicineTopic = 26
MeshID = D017824
bone cystis an expansile osteolytic lesionwith a thin wall, containing blood-filled cystic . The term aneurysmal is derived from its radiographic appearance.
Trauma is considered the initiating factor in the development of some
cysts, in documented cases involving an acute fracture. Local alterations in the blood flow are related to obstructions that are important in the development of an aneurysmal bone cyst.
The lesion generally arises in a pre-existing bone
tumor, this is because of the abnormal bones changes in hemodynamics. An aneurysmal bone cyst can arise from a pre-existing chondroblastoma, a chondromyxoid fibroma, an osteoblastoma, a giant cell tumor, or fibrous dysplasia. A giant cell tumor is the most common cause, occurring in 19% to 39% of cases. Less frequently, it results from some malignanttumors, such as osteosarcoma, chondrosarcoma, and hemangioendothelioma.
Aneurysmal bone cysts may be
intraosseous, staying inside of the bone marrow. Or they may be extraosseous, developing on the surface of the bone, and extending into the marrow.
# Initial phase of
# Active growth phase, characterized by destruction of bone tissue.
# Stable stage, where a formation of a bony shell and internal bony septa produce its soap bubble appearance.
# Healing phase where the cyst eventually heals into an irregular dense bony mass.
The tumor can have an occurrence anywhere that there is bone. Approximate percentages by sites are as shown:
* Skull and mandible (4%)
* Spine (16%)
* Clavicle and ribs (5%)
* Upper extremity (21%)
* Pelvis and sacrum (12%)
* Femur (13%)
* Lower leg (24%)
* Foot (3%)
The afflicted may have relatively small amounts of pain that will quickly increase in severity over a time period of 6-12 weeks. The skin temperature around the bone may increase, a bony swelling may be evident, and movement may be restricted in adjacent joints.
lesionsmay cause quadriplegiaand patients with skull lesions may have headaches.
Giant cell tumor of bone
* [http://bonetumor.org/tumors/pages/page151.html Bonetumor.org]
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