進行性の脳神経麻痺を呈した肺癌原発下垂体腺腫内転移の1例

Intrapituitary Adenoma Metastasis from Lung Cancer with Progressive Cranial Nerve Palsies: A Case Report and Literature Review

Ⅰ．はじめに

　下垂体へ転移を来す転移性脳腫瘍の報告は散見されるが，頭蓋外腫瘍が下垂体腺腫内に転移を来した症例は非常に稀であり，われわれが渉猟し得た限りでは自験例を含めて20例のみである．転移性下垂体腫瘍と下垂体腺腫内転移は発症様式が大きく異なる．今回われわれは既存の下垂体腺腫に肺癌が転移した症例を経験したので，文献的考察を加えて報告する．

　We report a rare case of metastasis to a preexisting pituitary adenoma. An 80-year-old man with a history of pituitary adenoma and lung cancer presented with recent onset of bilateral visual impairment, oculomotor nerve palsies, and severe headache. A CT scan revealed a pituitary tumor expanding into the suprasellar region and infiltrating the bilateral cavernous sinuses. We performed transsphenoidal surgery and diagnosed the tumor as lung cancer metastasis to the pituitary adenoma. After the surgery, visual impairment and severe headache were resolved, and the patient underwent radiation therapy for the residual tumor. To the best of our knowledge, 20 cases of metastases to pituitary adenomas have been reported in the literature. Clinical features of metastasis to a pituitary adenoma are different from those of metastasis to normal pituitary gland. In the case of a pituitary lesion with acute aggravation, one should be aware of the possibility of metastasis to preexisting pituitary adenomas.