{Reference Type}: Case Reports {Title}: Arteriovenous malformations as a presenting sign of PTEN hamartoma tumor syndrome: A case series. {Author}: Dykman M;Pillai NR;Lenhart K;Nicholson C;Boull C;Fritz E;Flanagan S;Maguiness S; {Journal}: Pediatr Dermatol {Volume}: 41 {Issue}: 2 {Year}: 2024 Mar-Apr 6 {Factor}: 1.997 {DOI}: 10.1111/pde.15435 {Abstract}: High-flow vascular malformations have been associated with multiple syndromes including capillary malformation-arteriovenous malformation (CM-AVM) syndrome, hereditary hemorrhagic telangiectasia syndrome, and less commonly, phosphatase and tensin homolog hamartoma tumor syndrome (PHTS). We present a series of three patients with clinically challenging complex AVMs who were found to have underlying PHTS. In all patients, diagnosis was delayed, and the presence of the AVM prompted sampling and genetic testing for PHTS in the absence of other clinical features of the condition. This series highlights the importance of screening for PHTS in the setting of high-flow vascular malformations.