[Clival chordoma in an infant; case report and review of the literature].

Skull base chordoma in infants is a very rare entity in spite of its congenital origin; only 11 clinical cases can be found in the literature so far. Here we report such a case and review the literature. The case is that of a 3.5-year old boy suffering from left abducent nerve palsy for 5 months. CT scan revealed an isodense mass lesion with bone destruction involving the clivus and left petrous apex, and was homogeneously enhanced on post-contrast study. MRI disclosed the clival tumor as a long T1 and long T2 mass. Angiogram showed no tumor stain. The tumor was preoperatively diagnosed as clival chordoma, and was partially removed via left transpetrosal-transtentorial approach. The tumor was found to extend into the subdural space through Dorrello's canal and compress the abducent nerve. Histological examination with H & E, PAS, mucicarmine, and reticulin stainings led us to a diagnosis of "typical chordoma". Electron microscopy demonstrated the mitochondria-endoplasmic reticulum complexes (MERC), glycogen granules, and vacuoles in the tumor cells. Postoperative irradiation (total dose 55 Gy) was performed. At present, 30 months after the operation, no evidence of tumor regrowth nor hypothalamus-pituitary deficiency is recognizable and the patient is free from left abducent nerve palsy. It is concluded that skull base chordoma in infants should be postoperatively irradiated in an appropriate manner.