History
A bulge in the groin or scrotal enlargement is the classic presentation of hernia or communicating hydrocele. Pain is generally not a prominent feature but may occur if a hydrocele expands quickly; tension in the wall may cause milder pain. Severe pain raises concern about a strangulated hernia. Very rarely, a hydrocele may become infected and cause pain.
Frequently, parents report an intermittent bulge. The bulge may reduce at night in the supine position. A history of vomiting, colicky abdominal pain, or obstipation suggests bowel obstruction, which may occur with an incarcerated or strangulated hernia.
Physical Examination
Examine the child in the supine and standing positions. If a bulge is apparent in the standing position, lay the child in the supine position. Resolution of the bulge in the supine position suggests a hernia or a hydrocele with a patent processus vaginalis (PPV).
If the bulge is not readily apparent, perform a maneuver to increase intra-abdominal pressure. For example, have the child simulate blowing up a balloon, cough, or press firmly on the abdomen. Restraining a baby's hands above his or her head causes the baby to struggle, potentially revealing an occult bulge that is not visible otherwise.
Transillumination of the scrotum displays fluid in the tunica vaginalis (TV), suggesting a hydrocele. However, this test does not fully exclude a hernia, because the bowel may also transilluminate.
Bowel sounds in the scrotum are strongly suggestive of a hernia. A bulge below the inguinal ligament is suggestive of lymphadenopathy.
Examiners may try to elicit the "silk glove" sign. Gently passing the fingers over the pubic tubercle may reveal a PPV. The thickened cord of a hernia or hydrocele sac within the spermatic cord provides the feel of two fingers of a silk glove rubbing together.
Unless a PPV results in hernia or hydrocele, it often goes undetected during physical examination.
Classification
Hernia
Indirect hernias protrude through the internal inguinal ring, lateral to the inferior epigastric vessels. They are caused by failure of the processus vaginalis (PV) to obliterate. Most inguinal hernias in children are the indirect type. The hernia may extend down the inguinal canal toward the labia or scrotum.
Complete inguinal hernias are indirect hernias that extend into the scrotum. The anatomic defect is similar to the defect of a communicating hydrocele, though the PPV is more widely patent in hernias.
Direct hernias protrude directly through the floor of the inguinal canal and are medial to the inferior epigastric vessels. In children, these hernias are rare and are usually observed only after prior inguinal surgery.
Hydrocele
Communicating hydroceles involve a PPV that extends all the way into the scrotum. In this case, the PPV is continuous with the TV, which surrounds the testicle. The anatomic defect is identical to the defect with an indirect hernia; however, the communication is smaller, so only fluid can pass into the PPV.
Noncommunicating hydroceles contain fluid confined to the scrotum within the TV. The PV is obliterated, and thus the fluid does not communicate with the abdominal cavity. Such hydroceles are common in infants, and the hydrocele fluid is usually reabsorbed before the infant reaches the age of 1 year.
Reactive hydroceles are noncommunicating hydroceles that develop from some inflammatory condition in the scrotum (eg, trauma or infection).
Hydrocele of the cord occurs when the PV obliterates above the testicle. A small communication with the peritoneum persists, and the PV may be open as far down as the top of the scrotum. A saclike area within the inguinal canal fills with fluid. The fluid does not extend into the scrotum.
Hydrocele of the canal of Nuck occurs in girls when fluid accumulates within the PV in the inguinal canal.
Abdominoscrotal hydrocele results from a minuscule opening in the PV. Fluid enters the hydrocele and becomes trapped. The hydrocele continues to enlarge and eventually bulges upward into the abdomen, causing a fluid-filled mass in the abdomen.
