Sterile abscess mimicking recurrent tumour in the cerebellopontine angle

Vestibular schwannomas are the most common tumours encountered in the cerebellopontine angle (CPA) region, accounting for 90 per cent of all lesions. Early pyogenic abscess following surgery and delayed abscesses due to retained foreign bodies have been reported. We describe a case of sterile abscess of unknown aetiology in the CPA region, occurring 13 years after surgical excision of a vestibular schwannoma. The clinical and radiological features were suggestive of recurrent vestibular schwannoma or malignant transformation. We believe this is the first reported case of delayed occurrence of sterile abscess in the CPA region. Further the diagnostic difficulties of such rare lesions occurring in the CPA after vestibular schwannoma surgery are discussed.