Myxopapillary ependymoma. Results of nucleolar organizing region staining.
BACKGROUND
Although myxopapillary ependymomas are generally benign with a tendency for slow growth and local recurrence, they are capable of spread within the nervous system and of extraneural metastasis. Histologic features have not been helpful in determining which patients are 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) staining method was used to determine if this technique was useful in the management of these tumors.


RESULTS
Five patients had total resections of encapsulated lesions, four had total resections of adherent tumors, and four had subtotal resections. Twelve received postoperative radiation therapy. With a mean follow-up of 80 months, 12 patients are well 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 0.4-1.64. The patient who died with intracranial spread had the highest number of NOR per cell.


CONCLUSIONS
Based on these data and a review of the literature, it is recommended that radiation be delayed until recurrence in tumors that have been totally resected. Local radiation therapy may be indicated in subtotally resected tumors. NOR staining shows promise in predicting the likelihood of spread of tumor. Patients with myxopapillary ependymomas should be followed indefinitely because of the potential for late recurrence, even after aggressive therapy.
Section of Neurological Surgery, University of Michigan Medical Center, Ann Arbor 48102.
D A
DA
Ross
P E
PE
McKeever
H M
HM
Sandler
K M
KM
Muraszko
D000293:Adolescent; D000328:Adult; D000368:Aged; D002455:Cell Division; D002648:Child; D004806:Ependymoma / Q000628:therapy / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D012189:Retrospective Studies