Perinatal/Neonatal
Case
. . . Presentation
. . . . . . . .
. . .
Meconium Periorchitis
Thomas E. Herman, MD
Marilyn J. Siegel, MD
Meconium peritonitis occurs when a bowel wall rupture occurs
during late fetal life or early postnatal life, allowing meconium to
enter the peritoneal cavity. This may be associated with voluvulus,
Journal of Perinatology (2004) 24, 53–55. doi:10.1038/sj.jp.7211014
CASE PRESENTATION
A full-term infant boy was born after an uncomplicated pregnancy.
The child was discharged at 2 days of life from the outside hospital.
The mother was told that the child had a hydrocele and the
scrotum was noted by her to be distended. Over the course of the
next month the scrotal swelling resolved. However, the patient
began to vomit. He had an upper gastrointestinal series performed.
The study was normal except for gastroesophageal reflux. No
masses or calcifications were identified in the abdomen. At 2
months of age, the mother noted a firm mass in the left
hemiscrotum. The child was brought to the emergency room where
a sonogram was performed (Figures 1 and 2). This study
demonstrated a normal right testicle with normal blood flow. The
left hemiscrotum demonstrated a large, very echogenic mass, with
some shadowing calcifications. The mass appeared to be
extratesticular, but inseparable from the testicle that it surrounded
laterally. The testicle itself was grossly normal, although slightly
distorted in contour by the mass. It was, however, of grossly normal
size and had normal blood flow.
DENOUEMENT AND DISCUSSION
The patient was taken to the operating room for an inguinal
exploration. The gritty scrotal mass was inseparable from the
testicle and an orchitectomy was performed. The pathology
specimen demonstrated a normal testicle surrounded by calcifying
meconium periorchitis (MPO).
MPO is a rare condition occurring in infant boys who have had
healed meconium peritonitis.1 Meconium is the greenish, viscous
intestinal content of the distal small bowel present after the fourth
month of fetal life. It contains swallowed amniotic fluid, bile salts,
bile pigments, cholesterol, mucin, pancreatic enzymes, intestinal
enzymes, squamous cells, lanugo hair and other cellular debris.
Mallinckrodt Institute of Radiology (T.E.H., M.J.S.) Washington University School of Medicine,
St. Louis, MO, USA.
Address correspondence and reprint requests to Thomas E. Herman, MD, Mallinckrodt Institute of
Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard,
St. Louis, MO 63110, USA
Figure 1. A (longitudinal), B (transverse with color Doppler) images
of the right testicle. The testicle is normal in size, contour, and
vascularity. The transverse images demonstrate normal color flow to
that testicle.
Journal of Perinatology 2004; 24:53–55
r 2004 Nature Publishing Group All rights reserved. 0743-8346/04 $25
www.nature.com/jp
53
Herman and Siegel
Meconium Periorchitis
Figure 2. A (longitudinal), B (longitudinal with color Doppler), C, and D (transverse images). A large echogenic mass is seen in the right
hemiscrotum, which has an ellipsoidal shape. Within the echogenic portion is a more hypoechogenic area with the appearance of a normal testicle
(arrows) with normal Doppler color flow. The echogenic portion was relatively hypovascular. The transverse images demonstrate the echogenic mass
(arrowheads) cloaking the lateral aspect of the testicle (arrows).
bowel atresia, or mesenteric vascular insufficiency.2 If the
ruptured bowel wall heals, there may be no evidence of the cause
or the site of perforation. This has been called healed meconium
peritonitis. Meconium in the peritoneal cavity initiates a sterile,
chemical foreign body peritonitis.3 Peritoneal calcifications may
develop subsequently. Three forms have been described:
fibroadhesive, either localized or generalized, and cystic.3 The
localized fibroadhesive is the most common resulting in linear
peritoneal calcifications. The generalized variety may have
ascites. Cystic meconium peritonitis occurs when the perforated
meconium is localized adjacent to the bowel loop resulting in a
focal cystic mass that appears as a thin-walled calcified cyst
radiographically.4 Extra-abdominal complications of meconium
peritonitis have been described2,5, including passage of
meconium into the scrotum through a patent processus
vaginalis and into the thoracic cavity through the foramen
of Bochdalek and systemic embolization of meconium. Passage
through the patent processus vaginalis in a male may result in
meconium periorchitis.
Many of the infant boys with MPO are reported to have had
reducible hydroceles at birth, often bilateral. However,
approximately 25% of patients did not have any scrotal abnormality
54
at birth.6 The meconium in the scrotum is rather quickly turned
into a fibrous solid mass. Patient age at time of diagnosis of this
mass varies from birth to 20 months, with the mean age being
1 month.1 Although there is an increased incidence of meconium
peritonitis in patients with cystic fibrosis, there has only been one
documented case of cystic fibrosis associated with MPO.1
Sonographically, MPO causes a well-defined scrotal mass
enveloping the testes and epididymis with echogenic shadowing
foci of calcification. Abdominal radiographs may demonstrate
peritoneal calcifications. However, as in our case abdominal
calcifications were absent in approximately 10% of cases.6 Other
causes of calcifications include teratoma, gonadoblastoma, torsion,
and infarction of the testis, calcifying Sertoli cell tumor and
metastatic neuroblastoma.1 Most cases of MPO have been
confirmed surgically but in a case with typical sonographic
findings and abdominal calcifications, surgery might be avoided.
The natural history in cases that have not been operated on
suggests that the masses spontaneously resolve.1 The testis has been
able to grow normally in one patient up to the age of 14 years.6
Surgical exploration is indicated when abdominal calcifications are
not present to confirm the diagnosis.6 This was the situation in the
patient described in this case.
Journal of Perinatology 2004; 24:53–55
Meconium Periorchitis
Surgically, the mass appears as a greenish, gelatinous, septated
structure, which has been confused with a lymphangioma.2 It has a
gritty feel because of the calcifications. Pathologically, there are
septated nodules of fibromyxoid stroma. These nodules are often
heavily calcified. No inflammation is present, except for some foreignbody giant cells and pigmented macrophages. Although the entity has
been called meconium granuloma, true granulomas are not present.1
References
1. Dehner LP, Scott D, Stocker JT. Meconium periorchitis: a clinicopathologic
study of four cases with a review of the literature. Hum Pathol 1986;17:807–12.
Journal of Perinatology 2004; 24:53–55
Herman and Siegel
2. Boccon-Gibod L, Roucayrol AM. Meconium periorchitis. Pediatr Pathol
1992;12:851–6.
3. Kimball D, Smith W. Meconium peritonitis with thoracic extension. AJR
1985;144:113–4.
4. Carroll BA, Moskowitz PS. Sonographic diagnosis of neonatal meconium cyst.
AJR 1981;137:1262–4.
5. Patton WL, Lutz AM, Willmann J, Callen P, Barkovich AJ, Gooding CA. System
spread of meconium peritonitis. Pediatr Radiol 1998;28:
714–6.
6. Varkonyi I, Fliegel C, Rosslein R, Jenny P, Ohnacker H. Meconium
periorchitis: case report and literature review. Europ J Pediatr Surg
2000;10:404–7.
55