Sirolimus for Cowden Syndrome With Colon Polyposis

Inclusion Criteria: * Cowden syndrome or other PTEN hamartoma tumor syndrome spectrum disorder * Confirmed pathogenic or likely pathogenic PTEN germline mutation on genetic testing * Previous colonoscopy with colon polyposis. This is defined for the study as either too many polyps to remove endoscopically as judged by the performing physician at the last colonoscopy or findings indicating at least an InSIGHT stage 1 score (over 20 polyps). * Age 18 or greater * Capacity to consent to study Exclusion Criteria: * Pregnancy or plans for pregnancy while on treatment or within 3 months of stopping treatment (for both women and men) * Chronic kidney disease * Chronic renal disease * History of colon cancer or colon adenoma with high grade dysplasia * History of colectomy