Aneurysmal bone cyst (ABC) is a
non-cancerous bone tumor composed of multiple varying sizes of
spaces in a bone which are filled with blood.
The term is a misnomer, as the lesion is neither an
aneurysm nor a
cyst.
It generally presents with pain and swelling in the affected bone.
[ Pressure on neighbouring tissues may cause compression effects such as neurological symptoms.][
The cause is unknown.][ Diagnosis involves medical imaging.][ ]CT scan
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...
and X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
show lytic expansion lesions with clear borders.[ MRI reveals fluid levels.][
Treatment is usually by curettage, bone grafting or surgically removing the part of bone.][
It is rare.][ Aneurysmal bone cyst was first described by Jaffe and Lichtenstein in 1942.]
Signs and symptoms
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.
Sites
Commonly affected sites are metaphyses of vertebra, flat bones, femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg.
The Femo ...
and tibia.
Causes
Aneurysmal bone cyst has been widely regarded a reactive process of uncertain cause since its initial description by Jaffe and Lichtenstein in 1942. Many hypotheses have been proposed to explain the cause and pathogenesis of aneurysmal bone cyst, and until very recently the most commonly accepted idea was that aneurysmal bone cyst was the consequence of an increased venous pressure and resultant dilation and rupture of the local vascular network. However, studies by Panoutsakopoulus ''et al.'' and Oliveira ''et al.'' uncovered the clonal neoplastic nature of aneurysmal bone cyst. Primary cause has been regarded arteriovenous fistula within bone.malignant
Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer.
A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...
tumors, such as osteosarcoma
An osteosarcoma (OS) or osteogenic sarcoma (OGS) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchyme, mesenchymal origin (and thus a sarcoma) and that exhi ...
, chondrosarcoma, and hemangioendothelioma.
Pathology
Histologically, they are classified in two variants.
* The classic (or standard) form (95%) has blood filled clefts among bony trabeculae. Osteoid tissue is found in stromal matrix.
* The solid form (5%) shows fibroblastic proliferation, osteoid production and degenerated calcifying fibromyxoid elements.
According to Buraczewski and Dabska, the development of the aneurysmal bone cyst follows three stages.
Diagnosis
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
and CT scan
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...
show lytic expansion lesions with clear borders.[ Expansion of cortex gives the lesion a balloon-like appearance. Larger lesions may appear septated.][ Bone scan shows outer radiotracer uptake, with a central dark area.]
Differential diagnosis
Following conditions are excluded before diagnosis can be confirmed:
Treatment
Curettage is performed on some people,phenol
Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire.
The molecule consists of a phenyl group () ...
, methyl methacrylate are considered for use to kill cells at margins of resected cyst.
Prognosis
20–70% recur after curettage.[
]
Epidemiology
It is rare.[ 80% occur in people age less than 20 years.][ It is second most common tumor of spine and most common benign tumor of pelvis in pediatric population.][
]
Additional images
File:Aneurysmal bone cyst - high mag.jpg, High magnification micrograph of an aneurysmal bone cyst
File:Aneurysmal bone cyst - intermed mag.jpg, Intermediate magnification micrograph of an aneurysmal bone cyst
See also
* Simple bone cyst (SBC)
* Giant cell tumor of bone
* Traumatic bone cyst
References
External links
{{Disorders of translation and posttranslational modification
Osteopathies
Vascular neoplasia