CS-6 A case of poorly differentiated chordoma with systemic metastasis

Abstract A case report: The patient was a 32-year-old man with diplopia. He was diagnosed as sphenoid sinusitis on MRI by a local doctor and visited an otolaryngologist. MRI showed extensive extension of neoplastic lesions from the clivus to the sphenoid sinus to the anterior ethmoid sinuses, bilateral cavernous sinuses, and the right medial and lateral pterygoid muscles. The right Lebiere’s lymph node was enlarged and thought to be a metastatic site. Based on the rapid growth and extension of the tumor, the patient was referred to the Department of Otolaryngology at our hospital on suspicion of sinonasal carcinoma. The possibility of chordoma could not be denied, so the patient was referred to our department. The patient underwent a joint endoscopic extended transsphenoidal tumor resection. The pathological diagnosis showed mitotic and necrotic features, and the majority of the cells showed highly atypical components without mucous substrate. However, brachyury, a marker for chordoma, was diffusely positive, and there was loss of INI1 (SMARCB1) expression. The final diagnosis was poorly differentiated chordoma. Postoperatively, the tumor in the right cavernous sinus grew rapidly, and the right eye became blind due to obstruction of the superior ophthalmic vein. The patient was treated with Gamma Knife as soon as possible in the hope of local control by high-dose irradiation, and after a total of three irradiations, the residual tumor shrank markedly and symptoms improved, but systemic metastasis occurred in a short period of time and the patient died. The number of cases of poorly differentiated chordoma has been reported rarely (more than 50), and it is more common in children and even rarer in adults. We report this case with a review of the literature.