When a 6-month-old boy returned to a pediatric urology clinic for a checkup before circumcision, his right testicle felt small and firm, raising concern that it had twisted around the time of birth. Surgery found the testicle healthy. The problem was a greenish-brown lump just below it: hardened meconium, the dark, sticky stool that builds up in a baby’s intestines before birth.
Ash N. Zawerton and Robert E. Steckler of Geisinger in Pennsylvania described the case in the Journal of Surgical Case Reports on Sept. 1. The condition, meconium periorchitis, is uncommon but well documented. What set this case apart was where the material ended up: outside the tunica vaginalis, the protective sac that normally surrounds the testicle.
A Normal Newborn Exam, Then a Firm Testicle Months Later
The boy, born at 39 weeks, was first seen at 14 days old for a circumcision evaluation. His genital exam was unremarkable, and he was asked to return at 6 months, when the hospital’s guidelines would clear him for general anesthesia for elective surgery.
At that visit, his right testicle was small and firm, and the epididymis, the coiled tube behind the testicle, appeared flattened. Those findings suggested an old perinatal torsion, in which the testicle twists and loses its blood supply around the time of birth.
Ultrasound complicated the picture. The right testicle measured 11 by 9 by 8 millimeters, smaller than the left at 16 by 10 by 9 millimeters, but it had adequate blood flow. Nearby, in the right groin area, sat a 1.4-centimeter lesion containing calcifications. The radiologist initially suspected pilomatrixoma, a benign growth that arises from hair follicle cells.
With the parents’ agreement, surgeons explored the area during the circumcision. The testicle looked normal. An irregular mass sat below it, within the gubernaculum, the cord of tissue that guides the testicle into the scrotum during development, and clearly outside the sac. A frozen section, a rapid microscopic analysis performed during surgery, was inconclusive. The team removed the mass and anchored the testicle in place, a procedure called orchidopexy. Final pathology confirmed a meconium fecalith, a hardened lump of meconium. The boy was doing well at his six-week follow-up visit.
How Stool Made Before Birth Can Reach the Scrotum
Meconium periorchitis is an inflammatory reaction that develops when meconium spills into the abdominal cavity before birth and travels into the scrotum through the processus vaginalis, a channel between the abdomen and scrotum that can remain open in infant boys.
That spillage is often tied to serious underlying problems, including intestinal blockage, twisting of the bowel, cystic fibrosis, or loss of blood supply to the gut. Classically, a baby is born with a soft, fluid-filled swelling that later firms up as the meconium calcifies. The condition is rare. One estimate cited in Archives of Disease in Childhood puts it at roughly 1 in 35,000 live births.
Fetal meconium carries essentially no bacteria. A 2021 Nature Microbiology study found no detectable microbiota in meconium before birth. Even so, meconium triggers intense inflammation when it touches surrounding tissue. The authors add that affected babies often have calcifications inside the abdomen as well, a finding that can help confirm the diagnosis.
This boy showed no sign of bowel trouble before or after birth. The pregnancy was uncomplicated, and his only other health issue, an enlarged head size, resolved without treatment. The authors offer several possible explanations for the unusual location. Meconium may have stuck to the gubernaculum before the testicle descended. Tiny lymphatic openings in the sac’s lining, which can move molecules across it, might have carried material through. Or early inflammation may have disrupted normal tissue barriers. None of these explanations has been proven.
Surgery Is Common, and Sometimes the Testicle Is Lost
Most cases resolve on their own over several years, and the authors note that surgery is not necessary when doctors strongly suspect the diagnosis. The difficulty is that a calcified scrotal mass on imaging is not specific. It can resemble more dangerous conditions, including testicular germ cell tumors, so many children end up in the operating room.
A 2021 review of 31 cases detected before birth found that 80.6% underwent surgery. The testicle was removed in 25% of cases, and the mass was cut out in 65%. Only two children had a biopsy during surgery confirming calcified meconium, and in both, surgeons left the mass in place.
The condition is not always harmless. A 2025 report in the journal Urology described associations between meconium periorchitis and abnormalities of testicular and scrotal development, and the Geisinger authors list testicular torsion among the problems sometimes seen alongside it. Long-term data on testicular function after the condition remain limited.
Parents Should Not Wait on Scrotal Changes
The Geisinger authors conclude that recognizing meconium periorchitis early can spare children unnecessary surgery that might remove or injure a healthy testicle. That lesson is aimed mainly at clinicians.
For parents, the case does not mean scrotal lumps in babies are harmless. Testicular torsion is a surgical emergency, and swelling, discoloration, or a lump in a baby’s scrotum should be checked promptly by a pediatrician or pediatric urologist. This report describes a single patient, and its proposed explanations for the unusual location remain theories.
Key Questions Answered
What did surgeons find?
A lump of hardened meconium, the stool formed before birth, sitting below the baby’s testicle and outside the sac that normally surrounds it.
What is meconium periorchitis?
It is an inflammatory reaction that occurs when meconium leaks into the abdomen before birth and travels into the scrotum through an open channel.
Why was this case unusual?
The meconium sat outside the tunica vaginalis rather than inside it, and the baby had no known bowel problems.
Was the baby’s testicle damaged?
It looked normal during surgery and was kept and anchored in place. The boy was doing well six weeks after surgery.
Do all cases need surgery?
No. Many resolve over years without surgery, but imaging often cannot rule out tumors, so surgical exploration is common.
What should parents watch for?
Any swelling, lump, discoloration, or apparent pain in a baby’s scrotum should be checked promptly by a clinician.
What remains unknown?
How the meconium reached a spot outside the sac is unproven, and long-term effects on testicular function are poorly studied.
