手術・cisplatin／etoposide併用化学療法・放射線療法の3者併用が奏功した松果体芽腫の1例

A Case of Pineoblastoma Successfully Treated with Surgery, Combined Chemotherapy of Cisplatin and Etoposide, and Radiotherapy

I．はじめに

　松果体部に発生する腫瘍のうち，松果体芽腫は高度悪性腫瘍で，髄芽腫などと共にprimitive neuroectodermaltumor（PNET）に属すると考えられているが，極めて少なく全脳腫瘍の0.1-0.3％とされている^12）．症例数が少ないため，本腫瘍の治療法に関するコンセンサスは未だ得られていない．今回われわれは，腫瘍内出血を生じ閉塞性水頭症による頭蓋内圧亢進症状ならびに痙攣重積発作にて発症した松果体芽腫の1例を経験し，手術・cis—ptatin／etoposide併用化学療法（PE療法）・放射線療法の3者併用にて良好な結果を得ることができた．本症例の経過につき記すると共に若干の考察を加え報告する．

A 5-year-old girl was admitted to another clinic be-cause of vomiting and convulsions. She was brought to our clinic after a ventriculoperitoneal shunt was in-serted. CT scan on admission in our clinic showed a tumor in the pineal region with tumoral hemorrhage. Tumor markers such as HCG, AFP, CEA, P-LAP were within normal range. A biopsy of the tumor was per-formed and the histological diagnosis was pineoblasto-ma. Her recovery was excellent and disseminated metastasis was not recognized. A subtotal removal of the tumor was performed through the occipital trans-tentorial approach.CT scan obtained shortly after the injury demonstrated a thin acute extradural hematoma with intracranial air under the subcutaneous hematoma in the left occipital region, and another hematoma with subarachnoid hemorrhage due to contrecoup head trauma in the right frontal region. We treated her conservatively with a common drip. She sometimes vomitted during the several hours after admission. CT scan six hours later showed that the contrecoup extradural hematoma had enlarged. Immediately, we carried out the evacution of the hematoma with decompressive craniectomy. Her scalp, cranium and frontal skull base over the extradu-ral hematoma were without injury, and multiple small haemorrhages were found to have occurred on the sur-face of the dura that had been separated from the inner table of the skull. After the operation, the patient reco-vered consciousness.

Contrecoup acute extradural hematoma is very rare. It seems that the appearance of hematoma in our case resulted from the frontal dural separation due to distor-tion of the cranium brought on by the force of the im-pact and the subsequent gradual growth of the hemato-ma under the stimulation of several bouts of vomitting.

She had no neurological deficits af-ter surgery. She then received two 5-day cycles of che-motherapy, consisting of intravenous administration of 20 mg/m²/day cisplatin and 60 mg/m²/day etoposide, and craniospinal radiotherapy. After these therapies,the tumor responded and disappeared completely. Fol-low-up radiographic investigations also demonstrated no abnormal evidence except for brain atrophy. She is attending a primary school without any problems. Pineoblastoma is quite rare and remarkably malig-nant. Hence, aggressive therapies including surgery, radiotherapy and chemotherapy is indicated for this tumor.