默克細胞癌（Merkel cell carcinoma; MCC）是一種罕見的原發性皮膚神經內分泌腫瘤，其預後差存活率也低，在美國發病率估計 3.2 ∼ 4.4 人/ 每百萬人- 年。通常 MCC 的病程發展快速，早期局部復發和遠處轉移率高達 25%，MCC 好發於 65 歲以上的老人，發病位置大多為暴露在陽光下的頭頸部區域約佔 55%，40% 在四肢和 5% 在軀幹。在本篇報告中提出了一名 75 歲於2008 年在本院治療 pT3bN0 stage III 的前列腺癌，2012 年又在右側耳前區發現 TXN1M0 stageIIIB 的 MCC 的病患。術後接受劑量為 61.2 Gy 的放射治療，文獻回顧表示積極的化放療可以提高局部控制率和生存率。

Merkel cell carcinoma (MCC) is a rare primary cutaneous tumor of neuroendocrine typeassociated with a poor prognosis and a low survival rate. It has an estimated age-adjusted incidence of3.2 to 4.4 per 1,000,000 person-years in the United States. MCC usually has an aggressive course withearly locoregional recurrence and high distant metastatic rates of up to 25% in most series. It usuallyaffects elderly people over 65 years of age. It preferably affects areas exposed to the sun: 55% in thehead and neck, 40% in the limbs and 5% in the trunk. Here we present a 75 year old case of cT0 pN1cM1 stage IV Merkel cell carcinoma of right preauricular area with pT3bN0, stage III prostate cancer.Postoperative radiotherapy was given to the patient for 61.2 Gy. A literature review of MCC indicatesthat aggressive radiotherapy can have a positive impact on overall local control and survival.