The Solid Variant of the Aneurysmal Bone Cyst in the Lumbar Spine Mimicking a Malignant Bone Tumor

The Solid variant of the aneurysmal bone cyst is clinically important, because its solid composition is comparable to that observed in osteosarcoma or osteoblastoma, presenting difficulty for the correct diagnosis. The fluid-fluid level, which is a common sign of the conventional aneurismal bone cyst, is not apparent in radiographs of the solid type. These cysts were localized, equally within the whole spine as compared to most conventional aneurysmal bone cysts in which are localized to the posterior neural arch of the cervical spine. In this particular patient case, a young male aged 11.5 years presented with lower back pain and radiating pain which was misdiagnosed as a malignant bone tumor. Surgical intervention was considered and the incisional biopsy and laminectomy were conducted due to the low possibility of malignancy. We present this case and literature reviews with radiological and pathological findings as an example of the differential diagnosis of malignant tumors.