術後24年目に脳転移を来した男性乳癌の1例

A Case of Male Breast Cancer with Brain Metastasis 24 Years after a Mastectomy

Ⅰ．はじめに

　男性乳癌は全乳癌の1％未満と少なく，乳癌の脳転移が10〜16％であることを踏まえると，男性乳癌の脳転移例は極めて稀である^10,11,16)．われわれが渉猟し得た限りでは，症例報告が散見されるのみであり，その臨床的特徴や治療方針，予後に関しては未だ一定の見解を得ていない．今回われわれは，発症から20年以上の長期間を経て脳転移を来した男性乳癌の1例を経験したので，若干の文献的考察を加えて報告する．

　Male breast cancer accounts for less than 1.0％ of all breast cancer cases, and its brain metastasis is very rare. We encountered a male patient in whom brain metastasis occurred more than 20 years after the development of breast cancer.

　The patient was a 78-year-old male who underwent surgery for right breast cancer 24 years ago. Nausea and anorexia had appeared 2 months earlier, and the patient was referred to our department because a brain tumor was suspected on MRI. A 4×4-cm tumorous lesion was observed in the right temporal lobe, and it was heterogeneously enhanced with gadolinium. Suspecting a metastatic brain tumor, tumor resection with craniotomy was performed. Through pathological examination, the patient was diagnosed with brain metastasis of the breast cancer. Whole-brain irradiation was additionally performed. The patient recovered smoothly without neurological deficit and was discharged. No intracranial recurrence was noted on follow-up imaging, but the general condition aggravated, and the patient died after 13 months.

　Breast cancer in males may metastasize to the brain after a prolonged period in rare cases, for which follow-up examinations by imaging may be necessary.