Cowden syndrome (CS) is a difficult to recognize, under-diagnosed genodermatosis characterized by the presence of multiple hamartomas in various tissues and an increased risk for malignancies of the breast, thyroid, endometrium, kidney and colorectum. When CS is accompanied by germline <i>PTEN</i> mutations, it belongs to the PTEN hamartoma tumor syndrome (PHTS; see this term) group.
