Aneurysmal Bone Cyst : Differential
Aneurysmal Bone Cyst (ABC) - Differential Diagnosis: ABC-like changes (previously called secondary ABC) are commonly seen in association with many primary benign and malignant bone tumors such as chondroblastoma, giant cell tumor, osteoblastoma, fibrous dysplasia, nonossifying fibroma, and osteosarcoma. It is important to differentiate between ABC arising de novo and ABC-like changes. Adequate sampling of any solid foci within ABC is important. The clinical and imaging features will also help point to the correct diagnosis. Other entities that enter into the differential diagnosis include solitary (unicameral) bone cyst, hemangioma, and central giant cell granuloma (for jaw lesions). One of the most important distinctions is from telangiectatic osteosarcoma (TO) since it can mimic ABC on imaging studies and gross morphology. The fibrous septa in TO contain overtly malignant cells with marked anaplasia. The image shows a blood-lake surrounded by fibroblastic proliferation with numerous osteoclast-type giant cells.