Discussion
Our case presented and continues to present significant challenges to the attending physicians.
Firstly, the diagnosis was challenging. Clinical signs and symptoms were nonspecific and were all associated with local compression, with no symptoms due to catecholamine excess. Preoperative MRI can be diagnostic, however is frequently confounded, as it was in our case, with schwannoma, meningioma or ependymoma. The initial histopathological diagnosis was also incorrect, having the review of the specimen changed the initial diagnosis.
Secondly, as is described in the literature[,9, 10,11,12,]., spinal PG disease recurrence can occur decades after surgical resection, which highlights the need for long follow up periods with regular imagiological surveillance.
Thirdly, the optimal therapeutic strategies after primary resection remain unknow. Adjuvant radiation was performed after the first resection, however solid evidence in the literature for this approach is lacking. A second surgery with complete resection was performed after the first recurrence. There is some evidence of superiority of this approach versus radiation therapy.
Lastly the very small number of reported cases of PG where leptomeningeal dissemination has occurred means that treatment must be determined on an individual basis. Our review of the literature identified 6 described cases [6,7]. [Taken together these cases seem to suggest an indolent, insidious nature of the disease, even in the setting of dissemination.
Therapeutic options are limited as somatostatin analogs do not cross the blood-brain barrier. Radiotherapy and alkylating agents that penetrate the CNS can produce disease stability and their role in the management of leptomingeal dissemination warrants further investigation [5,8, 9,13]
Documentation of rare cases such as this one is important for enhancing clinical awareness, stimulation of novel research into biomarkers of malignant potential and development of treatment protocols.