However, no tumors or other vascular lesions were detected in other systems that would constitute Cowden syndrome.<h4>Conclusion</h4>The rapid formation of multiple and complex dAVFs, coupled with not meeting the criteria for any other PTEN-related syndrome, unequivocally leads to the presentation of a novel phenotype of the PTEN germline variant. The gene discussed is PTEN; the disease is Cowden disease.