Considerations on diagnosis and surveillance measures of PTEN hamartoma tumor syndrome: clinical and genetic study in a series of Spanish patients per Laura Pena-Couso, María Ercibengoa, Fátima Mercadillo, David Gómez-Sánchez, Lucía Inglada-Pérez, María Santos, Javier Lanillos, David Gutiérrez-Abad, Almudena Hernández, Pablo Carbonell, Rocío Letón, Mercedes Robledo, Cristina Rodríguez-Antona, José Perea, Miguel Urioste, PHTS Working Group