Surgical treatment and radiotherapy of epidermoid cyst with malignant transformation in cerebellopontine angle.

We report surgical treatment and radiotherapy of an extremely rare case of malignant epidermoid cyst located in cerebellopontine angle. MRI and CT demonstrated the lesion with partial enhancement and calcification. During operation, we found the tumor attached tightly to surrounding tissue. Finally we achieved near total resection of it. Histopathology confirmed the diagnosis of epidermoid cyst with malignant transformation. With adjuvant radiotherapy, the patient underwent excellent recovery, and follow-up MRI demonstrated no obvious residue or recurrence of the tumor. Malignant epidermoid cyst can be diagnosed radiologically in combination with clinical presentation. Maximal removal plus adjuvant radiotherapy is the treatment of choice, although the general prognosis of it is poor.