Renal Cystadenocarcinoma and Nodular Dermatofibrosis is an inherited genetic predisposition to kidney, dermal and uterine cancer in German Shepherd Dogs. This condition manifests as a combination of abnormal masses in the kidneys and the skin of both male and female dogs and also the uterus in female dogs. Affected dogs usually present around 6.5 years of age with small, firm bumps under the surface of the skin, more commonly located on the limbs and head. The kidney tumors often form nodular masses and cysts that can cause the kidneys to become enlarged, abnormally shaped and scarred. Affected dogs often show signs of chronic kidney disease which may include frequent urination, blood in the urine, frequent drinking, depression, inappetence and weight loss. The disease typically presents over the age of 5, and tumors may not develop until dogs are 9 to 11 years of age. The average age of death for affected dogs is 9.3 years due to renal failure or metastatic disease. Puppies that inherit two copies of the FLCN gene Mutation most likely die very early in gestation; therefore, breeding two dogs with renal cystadenocarcinoma and nodular dermatofibrosis may result in reduced litter size.