腺樣囊狀癌是一種罕見的惡性腫瘤，三分之一到一半源自於唾液腺。它通常以無症狀的臨床表現、獨特的緩慢卻無止盡的生長模式以及有很高的機會侵犯神經來表現，但淋巴的轉移則很少見。遠端轉移可以在局部及區域沒有復發的情形下，距最初治療超過十年以上才復發。雖然遠端轉移到肺臟、肝臟以及骨骼常發生，轉移到腎臟則不常見。只有一小部份源自於乳房、腮腺、肺臟、淚腺、耳道和硬腭的腺樣囊狀癌轉移到腎臟的案例曾被報告過。就我們所知，目前文獻上尚無源自於口腔底的腺樣囊狀癌轉移到腎臟的案例被報導過。我們報告一位的歲的男性在手術治療口腔底腺樣囊狀癌20年之後，發生腫瘤轉移到腎臟的案例，並做文獻的回顧。

Adenoid cystic carcinoma (ACC) is a rare malignant tumor, and one third to half of which arises from the salivary glands. It usually shows remarkably asymptomatic c1inical course, unique slow-growing but relentless pattern and high incidence of perineural invasion whereas lymph nodes metastasis is seldom seen. Distant metastasis can occur without evidence of locoregional failure more than a decade after initial treatment. Although distant metastases to lung, liver and bone develop frequently, metastasize to kidney is uncommon. Only a small number of patients with ACC metastasize to kidney from the breast, parotid gland, lung, lacrimal gland, auditory canal, and hard palate have been reported. To our knowledge, renal involvement from a mouth floor origin has not been reported in the literature. We report a 68-year-old male patient who presented as metastatic adenoid cystic carcinoma to his right kidney 20 years after surgical treatment of ACC of the mouth floor.