Cryptorchidism

A 7-month-old boy is brought to the office for a routine well-child visit. The parent reports the patient has been feeding well and developing appropriately. Vitals are within normal limits. Physical examination shows a cooperative child. Cardiopulmonary examination is normal. The abdomen is soft with no organomegaly. Genitourinary examination demonstrates a circumcised penis of normal size. The right testis is located within the inguinal canal, and the left testis is palpable in the scrotum. If left untreated, which of the following complications is most likely to occur?