SURG-13. PATHOLOGICAL EXAMINATION OF MENINGIOMA RECURRENCE AFTER ABSORBABLE ARTIFICIAL DURA MATER RECONSTRUCTION

Abstract INTRODUCTION In meningioma surgery, the removal of the tumor and tumor-attached dura mater is essential. Due to its high affinity, absorbable artificial dura mater is used for the reconstruction of dural defects. In this study, we report a pathological examination of dural-like tissue in a case of meningioma that recurred at the same site after the use of absorbable artificial dura mater during initial surgery. METHOD We investigated two cases in which absorbable artificial dura mater was used for dural reconstruction during meningioma resection, and subsequently, a recurrent lesion was identified at the site of the dural reconstruction. We examined MRI images and surgical and pathological findings at the time of recurrence in these cases. RESULT All patients underwent total resection, and the pathological diagnosis was atypical meningioma. MRI images at the time of recurrence revealed multiple meningiomas along the artificial dura site. Gross findings during recurrent surgery indicated that the absorbable dura had been replaced by dura-like tissue, with the tumor also attached to the same site. Pathological findings showed bundles of fibrous tissue within the dura-like tissue, albeit with a sparser density compared to autologous dura mater. Meningioma cell invasion and angiogenesis were also observed in the dural-like tissue. DISCUSSION In all cases, multiple meningiomas were found along the dural-like tissue. This suggests that meningioma cells invading the dural-like tissue may have used it as a scaffold for meningioma recurrence. Future studies are necessary to determine the appropriateness of absorbable artificial dura mater for dural defect sites during malignant meningioma surgery.