PTEN hamartoma tumor syndrome (PHTS) encompasses four major clinically distinct syndromes associated with germline mutations in the tumor suppressor PTEN. These allelic disorders, Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome, and Proteus-like syndrome are associated with unregulated cellular proliferation leading to the formation of hamartomas. Thus far, an increased risk of malignancy has only been documented in Cowden syndrome; however, current recommendations advise that all individuals with PTEN hamartoma tumor syndrome follow the cancer surveillance strategies suggested for Cowden syndrome until further data indicate otherwise. Because any individual phenotypic feature of Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome are frequently present in the general population, many individuals often go undiagnosed and consequently do not benefit from available cancer surveillance strategies. Therefore, it is critical for clinicians to recognize the phenotypic features associated with these syndromes to accurately diagnose and provide preventative care. This overview details the clinical description of the PTEN hamartoma tumor syndrome and associated disorders, their diagnosis and molecular/genetic testing, as well as differential diagnosis for assessment of other hamartoma-associated syndromes.