Hereditary breast ovarian cancer and Lynch/hereditary nonpolyposis colorectal cancer syndrome account for most hereditary gynecologic cancers. In the absence of effective cancer screening and other preventative strategies, risk-reducing surgery in women who are known to be at genetic risk of BRCA-associated or of Lynch syndrome carcinomas is effective in significantly decreasing the lifetime risk of developing malignancy. Reflex genomic testing of high-grade ovarian cancers and reflex immunohistochemistry in endometrial cancers will lead to greater recognition of germline-associated cancers. Approaches to processing surgical specimens, the recognition and classification of cancer precursor lesions, and differentiation from their mimics are discussed.