Solid variant of aneurysmal bone cyst presenting as a giant cervical mass: A clinical, radiological, histopathological dilemma

Abstract

Background:Typical aneurysmal bone cysts (ABCs) are osteolytic, multicystic lesions with parietal sclerosis and blood-filled cysts. In rare instances, the cystic components may be completely absent. Such solid variants in ABC (s-ABC) exhibit a solid architecture; making the clinical, radiological, and histological differentiation from other solid bone tumors like osteosarcoma (especially giant cell rich osteosarcoma) and giant cell tumor, a difficult task.Case Report:We report the case of a 45–year-old male presenting with a giant solid cervical spine lesion. Histopathology revealed solid variant of ABC, even though the radiological and fine needle aspiration cytology studies pointed toward a giant cell tumor.Conclusion:We aim to discuss the clinical, radiological, and histological findings of solid ABC (a rare benign entity) vis-à-vis the common neoplastic entities of osteosarcoma and giant cell tumor. The histopathological nuisances in making the diagnosis of s-ABC are put forth, along with its impact on management of such giant bony spinal lesions.

Test yourself answer to question: Incidental left L5/S1 facet finding on MRI

“…The osteolytic appearance on CT, but lack of fluid-fluid levels, septations and cystic component on MRI, is more consistent with a solid variant rather than conventional ABC [5]. Solid ABC's commonly affect long tubular bones, with only 16 cases reported to date in the spine [5].…”

Solid Variant of Aneurysmal Bone Cyst of the Temporal Bone

“…Given their more solid architecture, SVABCs are often difficult to distinguish clinically and radiologically from other solid bone tumors such as osteosarcoma and giant cell tumor. 20 On radiography, SVABCs can exhibit varying degrees of focal osteoid production, with some lesions demonstrating an absence of the classic ABC cystic component altogether. In the present case, histology demonstrated a primarily cystic lesion with interspersed areas of osteoid formation.…”

Massive aneurysmal bone cyst of the skull base treated with denosumab

“…Left column displays tumor prior to treatment while right column displays ossified tumor after 18 months of denosumab evaluation is not uncommon. [3][4][5] This highlights the need for diligent histopathological evaluation in establishing an accurate diagnosis.…”