A hydrocele presents differently than torsion of the testicle or of an appendix testis, but can strongly mimic a true hernia It is most often a painless swelling that is noticed during a diaper change or at bath time; however, these entities may be indistinguishable until further evaluation Clinical Assessment History and physical examination will quickly begin to separate a hydrocele from an emergent problem Physical examination is often notable for a nontender scrotum, with a communicating hydrocele, in which the fluid can be compressed back into the abdomen However, this is not always the case, and a hydrocele can have a loculated component that does not decompress Classically, a hydrocele will transilluminate, and the testis can be seen “floating” in the middle of all the fluid Management Prepubertal boys will have communicating hydroceles, whereas older boys may have loculated scrotal hydroceles In newborns and young infants, hydroceles may resolve spontaneously However, if they have not resolved by around year of age, they are often repaired A hydrocele and a hernia have the same pathophysiology—a persistent processus vaginalis In a hydrocele, the opening is very small, while in a hernia it is larger A hydrocele can turn into a hernia Thus the family must be counseled on signs and symptoms of an incarcerated hernia, including pain, a mass that cannot be reduced, nausea, vomiting, inconsolable crying, and/or erythema If these symptoms occur, the patient should return to the emergency room The patient should be referred to a pediatric urologist on an outpatient basis for management of a hydrocele Undescended Testis Clinical Recognition Four percent of newborn males will have an undescended testis The incidence decreases to 1.6% by year of age, indicating that some undescended testes descend after birth Spontaneous descent rarely occurs after months of age The child with undescended testes beyond the age of months needs outpatient urologic consultation In the physical examination of a boy, an empty scrotum on one or both sides is a common finding, but it may not always indicate a true undescended testis Often this represents a retractile testis In a boy with a retractile testis, the active cremaster muscle attached to the small prepubertal