A retrospective analysis of 50 cases of posterior fossa epidermoid surgically treated between 1997 and 2007.
The mean duration from onset of symptoms to surgery was 2.5 years. Patients with cerebellopontine angle (CPA) epidermoids presented predominantly with trigeminal neuralgia (35%) and hearing loss (29%) while patients with fourth ventricle epidermoid cysts had features of raised intracranial pressure (ICP) and gait ataxia (69.2% each). The rate of recurrence was 9% in tumors considered totally removed and 93% in those subtotally removed. Of the 17 patients with recurrences, 3 (7.9%) underwent a second operation. The mean duration of follow up at first recurrence was 9.3 years.
The rate of recurrence is significantly higher after subtotal removal as compared to total removal of epidermoids on long-term follow up. Symptomatic recurrence requiring re-exploration is evident only after a long duration (∼10.9 year) following primary surgery. Hence, total removal without producing new neurological deficits should be the standard goal when operating on posterior fossa epidermoid cysts 1).
Malignant transformation of intracranial epidermoid cysts to squamous-cell carcinoma is a rare occurrence and only a small number have been reported to date. MRI recurrence in combination with neurological decline should prompt surgery to exclude malignant transformation. Solanki et al. describe the experience of such a case and contribute to the evolving series within the literature 2).