Bone Cyst

Bone Cyst

Cystic bone lesions are significant because they can mimic primary bone cancers. Aneurysmal bone cyst (ABC), simple bone cyst (SBC), intraosseous ganglion, and epidermoid cyst are the most common. Cystic lesions in bone can also be caused by degenerative joint disorders and hydatid cysts.Microscopic findings, age, gender, clinical presentation, lesion localization, and radiographic findings, as with other bone cancers, are relevant in the diagnosis of these lesions. ACCs, which can be primary or secondary, are blood-filled multilocular cystic lesions that generate osteoclast-like giant cells and reactive osteoid in the metaphysis of long bones and posterior components of vertebrae.In young individuals, BCC should be evaluated if there is membranous fibrous tissue in the metaphysis that is no larger than the epiphyseal growth plate and lacks laying epithelium. Intraosseous ganglion cysts are fibrous-walled nonneoplastic pseudoprecysts that form in the subchondral space and should not cause joint degeneration. Intraosseous epidermoid cysts are found in the skull bone and phalanges and are bordered with keratinized squamous epithelium.In bone cysts, no relevant immunohistochemistry markers have been identified. However, the presence of USP6 gene rearrangement in ACCs aids in the differentiation of primary and secondary ACCs.