Aneurysmal bony cyst of the temporal bone; case study and literature review

Aneurysmal bone cysts (ABC) are rapidly growing, benign, non-neoplastic osteolytic lesions that consist of an intraosseous destructive tumour and an extraosseous aneurysm-like cyst. We report a case of ABC of the left temporal bone in 53 years old female patient who presented clinically with swelling over the left temporal region for 5 months. CT and MRI features were suggestive of ABC. Surgical resection was performed and histopathology confirmed the diagnosis and on follow-up the patient was doing well. The pattient presented with gradually increasing painless swelling in the left temporal region for 8 months with intermittent pain in the swelling. There was no history of any trauma, ear discharge, vertigo, nausea, vomiting or seizures. Neurological and ophthalmological examination results were normal. Local examination revealed a non-tender, firm and hard mass, measuring approximately 3.5×3×3 cm in the left temporal region. Skin over the swelling was normal. CT scan showed mass on superior wall of the bony portion of the left external auditory canal with marked irregular osseous erosions, osteolysis and thinning of the surrounding temporal bone. On T1-weighted MRI, the above-described mass was of mixed signal intensity with internal septations and hyperintense areas within, suggestive of haemorrhage. On T2-weighted MRI, the mass showed increased signal intensity with fluid–fluid levels within, multiple internal septations and hypointense rim around the mass (suggesting capsule).All the components of the mass gave a ‘bubbly’ appearance.

Conclusion Aneurysmal bone cyst of the temporal bone is a rare manifestation .CT and MRI are the imaging modalities for evaluation of aneurysmal bone cyst, aiding in diagnosis and helpful in treatment planning.

Publication History

Article published online:
12 May 2023