副鼻腔奇形癌肉腫例

Teratocarcinosarcoma is a rare, highly malignant tumor, that occurs mainly in the nasal cavity and paranasal sinuses. The prognosis is poor because the tumor invades the surrounding tissues even from an early stage. We report a case of sinonasal teratocarcinosarcoma that was treated by transnasal endoscopic skull base surgery and radiotherapy. The patient was a 65-year-old man who presented with a 2-month history of recurrent left epistaxis. Examination revealed a mass in the left nasal cavity. Computed tomography (CT) revealed a tumor extending from the left ethmoid sinus to the sphenoid sinus, and bone destruction of the anterior skull base. Magnetic resonance imaging (MRI) revealed intracranial extension of the tumor, but no apparent invasion of the brain parenchyma. Biopsy findings led to the suspicion of olfactory neuroblastoma. Since an olfactory neuroblastoma was suspected by biopsy and the possibility of invasion of the brain parenchyma was low, we performed endoscopic endonasal skull base surgery. The tumor was resected with the bone of the skull base and the dura. The skull base was reconstructed with the skull periosteum, fascia lata, and a nasal septum flap. Postoperative histopathological examination revealed the diagnosis of teratocarcinosarcoma. Therefore, after the surgery, the patient received radiotherapy. One year and ten months after the radiotherapy, metastasis to the left cervical lymph nodes was found, and neck dissection was performed. A follow-up examination at 4 years after the radiotherapy showed no evidence of local recurrence or distant metastases to other organs. It was difficult to confirm the histological diagnosis before surgery, and the diagnosis could be confirmed only by histopathology of the resected tumor specimen. The main treatment modality for teratocarcinosarcoma is surgical excision. However, teratocarcinoma is a highly malignant tumor, and radiotherapy and chemotherapy may be useful in addition to surgery, to obtain a better prognosis.