Monarch Disease Ontology entry MONDO_0009047 (cryptorchidism) is the failure of one or both testes of a male fetus to descend from the abdomen into the scrotum during the late part of pregnancy. If not surgically corrected in early childhood, males may be at increased risk for testicular cancer later in life. Also known as: cryptorchidism (disease), cryptorchism, undescended testes, undescended testicle, undescended testicles, undescended testis.