Mrs. A. brought four-month-old son Max to the office for his well-check. His growth and development were excellent; head and neck were normal as well as heart, lungs and abdomen. Starting to undo the diaper, mom snapped up and said, “Oh, yeah. My husband and I want you to check his scrotum. It seems unusually large on the right side.”
Sure enough, the right scrotum was much larger than the left side, and appeared firm and tense. It did not seem tender to palpation and the skin was not red or inflamed. I could feel that both the right and left testicles were present and normal. Clearly there was fluid in the scrotum. When I pressed toward the abdomen the fluid would move around but not disappear. I turned the ceiling lights off and held a bright light against the scrotum. It transilluminated nicely, confirming that it was fluid in the scrotum. I reassured mom that he had a hydocoele, (pronounced hydro seal), which is very common in newborn males. It should not cause him any discomfort or problems, and should be gone by one year of age.
Mrs. B. called early in the morning to make an appointment for four-month-old son Eric. She had noticed that his right scrotum was twice the size of his left and she wanted to come in as an emergency. But since Eric seemed happy and in no pain she agreed to come for a regular appointment later that morning.
Walking in the room I could tell she was anxious and concerned. After Eric’s afternoon nap a couple of days ago she first noticed this. But when her husband came home from work, together they examined the baby and everything seemed fine. In the morning while changing his diaper, she noticed the large swollen scrotum again. Then she called the office in a panic.
Eric seemed quite happy. He was in no distress and actually was smiling and cooing. Mom undid his diaper. In a disappointed voice she said, “Darn it! It’s almost gone away again.” I examined Eric, finding both testicles to be normal and in their proper position. There was some fluid in the right scrotum. As I gently palpated the right, exerting constant pressure from the bottom toward the abdomen, the fluid gradually disappeared leaving the right scrotum looking exactly like the left. Mom said, “How did you do that?” I told her that Eric had a communicating hydrocoele and proceeded to explain the meaning.
When the male fetus is developing in the uterus, the testicles are situated within the abdomen near the kidneys. Around eight months of gestation the testicles migrate down into the scrotum. As they move down, they are accompanied by a lining of the abdominal cavity called the process vaginalis. This lining forms a sac around the testicle. Usually the walls of the sac fuse together to close off and ultimately form a ligament-like structure. In many cases, the walls of the sac do not fuse together leaving a space around the testicle. Fluid can accumulate around the testicle, hence forming a hydrocoele.
Hydrocoeles are quite common. The literature reports that anywhere from 10% to 50% of normal male newborns have them. Since the testicles migrate into the scrotum at around eight months of gestation, hydrocoeles are more common in pre-term males, as would be expected. Hydrocoeles are benign and do NOT cause any problems for the infant. The vast majority of them disappear within the first year of life as the fluid is ultimately absorbed by the surrounding tissue. If a hydrocoele is still present by 18 months of age, a pediatric surgeon or urologist should give an evaluation. This would be very uncommon.
When the testicle migrates down into the scrotum, if the sac-like structure, the process vaginalis, does not close off there is a potential communication between the abdomen and the scrotum. This is what happens with a communicating hydrocoele. As a result, the fluid from the abdominal cavity may intermittently fill the scrotum. That was the case with Eric. Mom noticed a swollen and large scrotum in the afternoon, then it was gone by evening. When she made the appointment it was bigger than ever. By the time I saw him it was probably 50% smaller than when she had phoned. After examining Eric, I was able to milk the fluid out of the scrotum back into the abdomen due to the communication with the abdomen. Like hydrocoeles, communicating hydrocoeles do not cause any symptoms or problems for the infant. However, because of the persistent communication with the abdomen, this is now a hernia waiting to happen. Upon diagnosing a communicating hydrocoele, it should trigger a consult with a pediatric surgeon. Most of these will be repaired on an elective basis (hernia repair). This is the standard of care at the moment. However, recent surgical literature suggests that observation alone may be sufficient. This should be left up to the surgeon.
Max’s hydrocoele was evaluated at each well-check and, as expected, it completely disappeared by his nine month visit. The pediatric surgeon saw Eric, and it was determined that he did in fact have a large hernia on the right side. There was also a smaller one on the left side that was very subtle. At the recommendation of the surgeon Eric had a bilateral hernia repair on an elective basis a month later. He did fine. When I saw him at his nine month visit mom commented how well he had done and how it seemed light years since he went through that.