殿部腫瘤として発症した前仙骨部髄膜瘤に合併した類上皮腫の一例

抄録

  The authors report a rare case of an anterior sacral meningocele (ASM) associated with an epidermoid cyst, manifesting as an increasingly enlarged subcutaneous mass in the gluteal region. A 66-year-old male presented with a pygal mass lesion. Plain radiographs and three-dimensional computed tomography (CT) demonstrated a scimitar defect of the sacrum. Magnetic resonance images (MRI) revealed two cystic mass components in the presacral and subcutaneous region, which appeared to be continuous with the dural sac. Subsequent to sacral laminectomy, an exploration of the ostium was performed. However, during surgery, we could not find the communication between the thecal sac and the cysts. Reconstruction of the dural sac and suture ligation of both cysts were performed after resection of the cyst wall. The histological diagnosis was neutrophil epidermoid cyst, based on the finding in which the cyst wall consisted of squamous epithelia with infiltration. The patient remained neurologically intact postoperatively and had no further gluteal mass lesions. Follow-up MR images obtained 9 months after surgery showed a gradual reduction in size of both cystic components.