Early recurrence of an intracranial epidermoid cyst due to low-grade infection: case report.

Intracranial epidermoid cysts are slow-growing lesions, which may recur after incomplete resection, but do so over many years. The authors present the case of an epidermoid that repeatedly recurred over a short period, which was discovered to be secondary to a low-grade bacterial infection. A 30-year-old woman presented with signs and symptoms related to brainstem and cranial nerve compromise from a large cerebellopontine angle epidermoid cyst. She underwent a subtotal excision of a macroscopically and histologically typical epidermoid. The lesion recurred within 1 year of surgery, but with atypical radiological appearances. No systemic or local evidence of infection was found during a second resection. A further large recurrence with the same atypical features occurred after another 6 months, necessitating a third surgical resection. On this occasion, the atypical cyst contents grew coagulase-negative Staphylococcus after prolonged culture in an enrichment medium. Following a course of appropriate antibiotics, the residual cyst contents completely resolved. This case highlights an unusual complication of an epidermoid cyst. Early recurrence of an epidermoid, even in the absence of overt evidence of infection, should produce a high index of suspicion that there may be a low-grade infective cause. Surgical excision coupled with antibiotics resulted in a symptomatic and radiological recovery.