Background: Myxopapillary ependymoma (MPE) is a rare subtype of ependymoma that develops almost exclusively within the spinal cord. Despite its benign biological nature, MPE has a propensity to recur locally or distantly. Although variables influencing the prognosis, such as age, the extent of surgery and radiotherapy, have been widely discussed, no definitive standard has been established. Compared to other spinal tumors, many fewer histological markers have been elucidated to assist the determination of the prognosis.
Methods: Twenty-seven patients who underwent resection of MPE were enrolled. We determined their demographic features, imaging characteristics, clinical presentations and outcomes, surgical procedures and histological properties by chart review, telephone contact, reviewing of surgical notes, pre-/postoperative imaging and immunohistological staining.
Results: GTR (gross total resection) was achieved in 18 patients (66.7 %) and STR (subtotal resection) in 9 (33.3 %). Although GTR rendered a better disease control rate, the difference was not significant. Pediatric patients suffered from a greater risk of recurrence as well as a shorter period to disease relapse. In the majority of cases, we observed the overexpression of platelet-derived growth factor receptor α (PDGFRα), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-14 (MMP14). Epidermal growth factor receptor (EGFR) was observed in the tumors of 7 of 23 nonrecurrent patients, but not in any recurrent tumors.
Conclusions: The results of the present study indicate that the extent of resection and age are major factors related to tumor recurrence. Therefore, gross total resection is recommended whenever possible unless following neurological dysfunction is predictable. Moreover, pediatric patients need considerable attention after surgery, particularly in the early stages. PDGFRα, MMP2 and MMP14 may be new diagnostic and therapeutic targets and EGFR a potential predictor of improved prognosis for MPE.
Keywords: Epidermal growth factor receptor; Gross total resection; Myxopapillary ependymoma.