Cutaneous metastasis is a rare complication of visceral malignancies. We present a very unusual case of a 33 year-old seemingly healthy man with a sudden and rapidly enlarging skin lesion that was diagnosed as a skin metastasis of his visceral malignancy. Abdominopelvic CT scan revealed thickening of the anterior wall of the urinary bladder and the fundus and body of the stomach. Skin biopsy histopathological findings were suggestive of poorly differentiated metastatic carcinoma. The origin of the primary carcinoma was bladder adenocarcinoma or/and gastric adenocarcinoma, but the tumor was so poorly differentiated that the original source of the tumor could not be defined with certainty.