Recent advancements in cancer treatment have increased the incidence of secondary tumors and metachronous tumors by means of improving survival rates. Increased risk of secondary cancer is observed after radiotherapy and chemotherapy episodes. It is a clinical observation to now encounter recurrences many years after a successful treatment or a primary resection of a tumor. How a tumor cell persists alive but stable and how it demonstrates its tumorigenic potential remain to be clarified. A patient with colon adenocarcinoma and coexisting malignant melanoma who presented synchronic metastasis in the follow-up is presented in this manuscript.