MYXOPAPILLARY EPENDYMOMA - RESULTS OF NUCLEOLAR ORGANIZING REGION STAINING

Background. Although myxopapillary ependymomas are generally benign wi th a tendency for slow growth and local recurrence, they are capable o f spread within the nervous system and of extraneural metastasis. Hist ologic features have not been helpful in determining which patients ar e at risk for recurrence or dissemination, making management decisions difficult. Methods. A retrospective review was conducted of 14 cases of myxopapillary ependymoma. The nucleolar organizing region (NOR) sta ining method was used to determine if this technique was useful in the management of these tumors. Results. Five patients had total resectio ns of encapsulated lesions, four had total resections of adherent tumo rs, and four had subtotal resections. Twelve received postoperative ra diation therapy. With a mean follow-up of 80 months, 12 patients are w ell and disease-free. Two patients have had recurrences after surgery and irradiation, leading to death in one and disability in the other. The mean number of NOR per cell in eight specimens ranged from 0.4-1.6 4. The patient who died with intracranial spread had the highest numbe r of NOR per cell. Conclusions. Based on these data and a review of th e literature, it is recommended that radiation be delayed until recurr ence in tumors that have been totally resected. Local radiation therap y may be indicated in subtotally resected tumors. NOR staining shows p romise in predicting the likelihood of spread of tumor. Patients with myxopapillary ependymomas should be followed indefinitely because of t he potential for late recurrence, even after aggressive therapy.