Cowden syndrome is a rare genodermatosis of autosomal dominant inheritance characterized by multiple hamartomas in several organs and an increased risk of malignancies. We present the case of a 53-year-old man with a history of benign and malignant thyroid disease, intestinal polyposis, and Chiari malformation. He had several trichilemmomas, papillomatosis of the oral cavity, macular pigmentation of the glans penis, among other clinical features suggestive of Cowden syndrome. Given the suspicion, genetic study was conducted and PTEN mutation was identified. Cowden syndrome affects 1:200,000 individuals. Mucocutaneous lesions are almost always present and there may be other typical features involving other organs, namely thyroid, colon, and brain. Mucocutaneous lesions may be the initial manifestation of this disorder and usually precede the onset of malignant lesions, making timely diagnosis essential for proper monitoring and screening.