DISCUSSION
The incidence of PBS is estimated to occur in 1:40,000 live births with
more than 95% affecting males, its characterized by triad of deficient
abdominal wall muscles, bilateral cryptorchidism and abnormalities of
urinary tract such as hydronephrosis, hydroureter/mega ureter and
persistent urachus, megacystis with megalourethra (1,2). Literature on
the cause and embryogenetic factors of PPBS and PBS is controversial,
majority postulates that its due to three possible factors occurring
during embryogenesis; like severe bladder outlet obstruction, dysgenesis
of yolk sac and possibly due to abdominal muscle deficiency secondary to
migrational defect of mesoblast during early 1sttrimester of pregnancy (1,2,8). Prognosis of infants with PBS is poor
with IUFD, still births and early infant death being common (5,9,10).
Physical finding that support the diagnosis of PBS include a penile
abnormalities (megalourethra, urethral atresia), patent urachus and
musculoskeletal abnormalities (1,2,4,7). The clinical severity of PBS is
widely variable, depending upon the timing, location, and degree of the
embryologic insult. Some patients have severe manifestations which lead
to still birth or infant death while others demonstrate very mild
disease which requires little or no therapy (6,9,11).
The terminology of “Pseudo Prune Belly Syndrome (PPBS) has been
Suggested to define those who do not complete the triad of PBS (1,4,12).
PPBS is a term used to describe infants who do not fulfill the criteria
of classic PBS, consisting of abdominal wall muscle deficiency or
hypoplasia, urologic abnormality, and cryptorchidism, terms such as
“incomplete prune belly syndrome” or “partial prune belly Syndrome”
have been used to describe children cryptorchidism, mild urinary tract
abnormalities and mild or unilateral deficiency of abdominal
musculature: deficient prune like abdominal wall and normal
genitourinary system. Numerous report was described in children with
only mild diastasis of the rectus abdominis musculature or abdominal
wall deficiency with normal urinary tract imaging that the syndrome goes
unrecognized (8,11). The term “pseudo prune” or partial prune can then
be applied to a patient once the urologic hallmarks of PBS are
recognized on urologic imaging that is done for indications other than
PBS (1). PPBS includes patients who exhibit: (1) unilateral abdominal
wall muscular deficiency, cryptorchidism, and urinary tract anomalies;
(2) abdominal wall muscular deficiency alone; (3) abdominal muscular
deficiency with either urinary tract anomalies or cryptorchidism; or (4)
characteristic urinary tract anomalies and cryptorchidism but normal
abdominal wall musculature (3,4). Sometimes, abdominal wall muscular
hypoplasia is subtle or limited to diastasis of the rectus abdominis
muscles (4).
Although the incomplete expression of the classic triad illustrated by
our case is stated to occur at the same incidence as the complete triad,
PPBS has not been emphasized in the literature (3,4). PPBS is generally
characterized by partial or unilateral abdominal wall deficiency or
unilateral undescended testis that can usually be palpable in the
inguinal canal (4,11). Our patient is case of PPBS, which can be
considered as a possible variant of the syndrome.