頭蓋底腫瘍の発症経過をとった腎細胞癌の2例

Skull base metastasis from renal cell carcinoma presenting as abducens nerve paresis:report of two cases

I．はじめに

　腎細胞癌は肺，骨，肝に転移しやすく，脳転移も多い．また，原発巣である腎細胞癌が発見される以前に，その転移巣により発症することも稀ではない^4）．進行腎細胞癌においては頭蓋底転移は稀ではないが，頭蓋底腫瘍にて発症することは少ないと考えられる．われわれは脳神経症状により発症した頭蓋底腫瘍において，その腫瘍病理組織型より腎細胞癌と診断された2症例を経験した．これらの症例の発症様式，神経放射線学的所見を中心に報告する．

We report two cases of skull base metastasis from re-nal cell carcinoma. Case 1: A -55-year-old female pre-sented with a skull base tumor located on the clivus. Partial removal of the tumor was performed via the transsphenoidal approach. Case2: A 44-year-old male presented with a skull base tumor occupying the orbit-al, nasal, and paranasal cavities. The first operation, partial removal of the tumor, was performed via the transsphenoidal approach. Thereafter, the tumor re-growth and the patient's symptoms were progressive, so a second operation was performed via Le-Fort Ⅰ cra-niotomy to prevent cranial nerve dysfunction and air way obstruction.

The initial symptom of these two cases was abducens nerve paresis, which is caused by the tumor extending from the clivus to the cavernous sinus. The neuro-radiological features were the destruction of skull base bone and angiographic tumor stain. Histopathological examination of the surgically resected specimens re-vealed clear cell carcinoma, and thereafter they were diagnosed as skull base metastasis from renal cell carci-noma. We emphasize the necessity of a thorough medical workup to enable speedy diagnosis of renal cell carcinoma in such cases.