Median Genital Raphe Anomalies

Abstract

Raphe means the line of union of the two halves of various symmetrical body parts, and the term median raphe refers to the perineal raphe, which is also known as the median raphe of the perineum; and it is divided anatomically to: penile raphe, scrotal and perineal raphe. This line starts just anterior to the anus and extends through the scrotum, continuing on the ventral surface of the penis and prepuce; it is usually darker in colour than the surrounding skin, generally deep pink or brown. © Springer International Publishing Switzerland 2017. All rights are reserved.

Full text

Mohamed Fahmy
Congenital Anomalies
of the Penis

103
© Springer International Publishing Switzerland 2017
M. Fahmy, Congenital Anomalies of the Penis, DOI 10.1007/978-3-319-43310-3_16
Median Genital Raphe Anomalies
Abstract
Raphe means the line of union of the two halves of various symmetrical
body parts, and the term median raphe refers to the perineal raphe, which
is also known as the median raphe of the perineum; and it is divided ana-
tomically to: penile raphe, scrotal and perineal raphe. This line starts just
anterior to the anus and extends through the scrotum, continuing on the
ventral surface of the penis and prepuce; it is usually darker in colour than
the surrounding skin, generally deep pink or brown.
Keywords
Absent median raphe • Prominent median raphe • Wide median raphe •
Splitted raphe • Bucket handle malformation • Median raphe cyst • Beaded
median raphe • Pearly penile papules
Definition
Raphe means the line of union of the two halves
of various symmetrical body parts, and the term
median raphe refers to the perineal raphe, which
is also known as the median raphe of the perineum;
and it is divided anatomically to: penile raphe,
scrotal and perineal raphe (Fig. 16.1). This line
starts just anterior to the anus and extends through
the scrotum, continuing on the ventral surface of
the penis and prepuce; it is usually darker in
colour than the surrounding skin, generally deep
pink or brown (Fig. 16.2).
Genital Median Raphe (GMR) is a result of a
fetal developmental phenomenon whereby the
scrotum (the developmental equivalent of the
labia in females) and penis close toward the mid-
line and fuse, to form this line which represents
the superficial effects of the midline fusion of
ectoderm along these areas, as development pro-
gresses, the ectodermal edges of the urethral
groove begin to fuse to form the median raphe [1]
(Fig. 16.3). This embryological line or ridge may
be subjected to a various anomalies, which not
well known by many practitioners, and can thus
pass unnoticed, these anomalies will be high-
lighted with some details.
16
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of this chapter (doi:10.1007/978-3-319-43310-3_16) con-
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104
Fig. 16.2 Normal appearance of median raphe
Fig. 16.3 Urethral groove before fusion to form median
raphe from the ectoderm
Nomenclature
Genital raphe, Penile raphe, Genitoperineal raphe
and Median raphe.
16.1 Incidence
Median raphe anomalies are not so common and
rarely taken into consideration; and curiously these
conditions receive little attention even in
genitourinary textbooks, and they are generally clas-
sified in literature into one of only two groups: cysts
or ectodermal canals. These anomalies are formed
from outgrowing endoderm and ectoderm after clo-
sure. In a survey of 2880 babies aged from 1 day to
7 weeks we detect an overall incidence of about 2 %,
with a wide spectrum ranging from simple anomaly
like prominent raphe to a raphe cyst [2].
Fig. 16.1 Anatomical segments of median raphe
Penile Raphe
Scrotum
Anus
Scrotal Raphe
Perineal Raphe
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105
16.2 Significance of GMR
Anomalies
Pathology of the GMR anomalies may be simple,
carries no direct impact on the child health and in
many occasions needs no surgical intervention,
but its significance mainly came from the serious
associated anomalies, which are usually hidden
and may be only disclosed after detection of
GMR anomalies; as we will see in cases of intact
prepuce megameatus for example. Recently with
the advance in ultrasound techniques, median
raphe could be visualised accurately antenatally
as an indictor not only for sex determination,
where the male fetus was recognised by the pres-
ence of the scrotal sac as a rounded echogenic
structure separated by an echogenic median
raphe [3], but also may give a hint about an asso-
ciated anomalies; like hypospadias, and as we
will see from the wide range of GMR anomalies,
it may be used in the future for more detection
and diagnosis of other congenital genitourinary
anomalies antenatally.
Anomalies of median raphe classified to:
1. Absent median raphe
2. Prominent Median Raphe
3. Wide median Raphe
4. Splitted median Raphe
5. Hyperpigmented Median Raphe
6. Short Contracted Raphe
7. Deviation of Raphe
8. Bucket handle malformation
9. Median raphe cyst
10. Beaded median raphe
11. Pearly penile papules
16.2.1 Absent Median Raphe
Complete absence of penile raphe with flat redun-
dant skin covering the penile shaft is a very rare
anomaly which may be detected with different
types of hypospadias (Fig. 16.4), and it is also
reported as an associated anomaly with trans-
verse testicular ectopia [4], usually perineal raphe
is normal in such cases.
16.2.2 Prominent Median Raphe
Normally GMR identified by its little prominence
than the rest of the penile skin around it, but
abnormal extensively prominent raphe looks like
a ridge was detected in association with other
anomalies like hypospadias, imperforate anus,
and in rare cases of Townes–Brocks syndrome (an
autosomal dominant disorder with multiple mal-
formations and variable expression, major find-
ings include external ear anomalies, hearing loss,
preaxial polydactyly and triphalangeal thumbs,
imperforate anus, and renal malformations) [5]..
In many severe cases of hypospadias the GMR
was a very prominent midline ridge extending
from the the anal orifice to the hypospadiac uri-
Fig. 16.4 Absent penile raphe with coronal hypospadias
in a circumcised child
16. 2 Significance of GMR Anomalies

106
nary meatus (Fig. 16.5). Prominent GMR have to
be differentiated from others anomalies like:
wide, hyperpigmented and splitted types.
16.2.3 Wide Median Raphe
Abnormal wideness of median raphe; either flat
or prominent probably due to the defective fusion
of the ectoderm, or failure of maturation of the
midline mesodermal components, and it may be
presented as a prominent widely separated
median raphe which may be detected in cases of
anorectal malformations (Fig. 16.6). This wide-
ness may affect the whole penile, scrotal and
perineal raphe, or may be partially affecting only
the penile raphe, and such cases may hide a
megameatus with an intact prepuce (Fig. 16.7)
(This issue will be discussed with some details in
Chap. 20). Wide GMR may be contracted with
shortening of the scrotal raphe and results in dis-
figurement of scrotum (Fig. 16.8), such cases
need excision of the abnormal raphe tissue with a
meticulous closure of the midline with an absorb-
able fine suture to avoid a further scar
contraction.
Fig. 16.5 Prominent Raphe with an anterior penile
hypospadias
Fig. 16.6 Wide median Raphe associated with an imper-
forate anus
16 Median Genital Raphe Anomalies

107
16.2.4 Splitted Median Raphe
(Median Raphe Bifurcation)
Splitted median raphe was probably due to the
defective fusion of the ectoderm; raphe may be
splitted and bifurcated just proximal to the hypo-
spadiac meatus (Fig. 16.9), or it may be splitted
at the root of the penis to be seen at the dorsum of
curved penis, with severe penile curvature and
proximal hypospadias (Fig. 16.10). Excision of
this deformed raphe should be considered during
hypospadias repair.
16.2.5 Hyperpigmented Median Raphe
Hyperpigmentation of the median raphe, in compari-
son to its normal dark appearance, was the most com-
mon anomaly detected [2], and it could be associated
with other anomalies like hypospadias and anorectal
anomalies. Although this abnormal median raphe
Fig. 16.7 Partially wide penile raphe with a hidden intact
prepuce megameatus
Fig. 16.8 Wide thick and contracted median raphe disfig-
uring scrotum
Fig. 16.9 Bifurcated median raphe around hypospadiac
meatus
16. 2 Significance of GMR Anomalies

108
pigmentation is not fully understood, it may be due to
the presence of lipochrome, diffuse melanosis of its
epithelial lining or excess presence of melanocytes
[6]. Hyperpigmentation may be a normal variation in
black races, and this abnormality may associated
other described GMR malformations; like wide,
splitted and contracted raphe (Fig. 16.11).
16.2.6 Short Contracted Raphe
Short contracted raphe may be associated
webbed penis, penile chordee and hypospadias,
in many cases of webbed penis there is no defi-
cient ventral skin, but it is only the contracted
short raphe which gives this picture and it neces-
sitated postponing routine circumcision with a
subsequent penile reconstruction with either
removal of the contracted raphe from the ventral
aspect or it may need a rotation skin flap
(Figs. 16.12 and 16.13). In Fig. 16.14 we can see
a very rare developmental anomaly of a short
contracted median raphe anchoring the penis
completely to the scrotum, with lose of peno-
scrotal angle and space.
Fig. 16.12 Contracted median raphe gives the appear-
ance of webbed penis
Fig. 16.13 Case in Fig. 16.12 after excision of the con-
tracted raphe and penis straightening
Fig. 16.10 Splitted GMR at the dorsum of severely
curved penis
Fig. 16.11 Hyperpigmented median raphe
16 Median Genital Raphe Anomalies

109
16.2.7 Deviation of Raphe
Raphe deviation to one side is not rare, but it
could pass unnoticed by the parents, the child, or
even unexperienced paediatrician, examination
of the penoscrotal raphe is simple to perform and
could aid in the early diagnosis in children with
milder forms of this condition, which could be a
normal developmental variation without any
associated other anomalies, also many cases of
isolated penile rotation without hypospadias had
a high incidence of raphe deviation to the oppo-
site side of penile rotation, which may indicate
that penile deformity is secondary to abnormal
position of GMR (Fig. 16.15).
Penile raphe deviation to one side or its bifur-
cation may hide a different grades of associated
hypospadias; (32 % of cases), and this is consid-
ered as one of the genital anomalies associated
with a hypospadiac defect, and in such cases the
deviation is more commonly to the right side
(60 %) [2] . Interestingly, however, 90 % of the
normal children with raphe deviation it deviates
to the left [7]. Diagnosis of hypospadias, its
degree, severity and other associated anomalies
related significantly to raphe deviation [2]
(Figs. 16.16 and 16.17).
Another study suggests a strong correlation
between children with raphe deviation and
hypospadias, with an 88.1 % of the children
with the condition demonstrating raphe devia-
tion, with the low incidence of raphe deviation
in normal children, indicates that this finding
could prove to be particularly useful as a predic-
tor of hypospadias in infants with nonretractile
foreskin [8].
GMR deviation to one side, as we can see in
Figs. 16.18 and 16.19 and the attached video
(Video 16.1), may be a significant signs for
detection of rare cases of megameatus variant of
hypospadias with an intact normal prepuce
(raphe deviation detected in 75 % of cases of
IPM in our series, which not yet published), and
this will be helpful medically and medicolegally
for surgeons and practitioners doing circumci-
sion for infants, specially in countries practising
circumcision for all infants with a religious
background.
Fig. 16.14 A rare case of short contracted median raphe
anchoring the penis to the scrotum
Fig. 16.15 Deviation of GMR without hypospadias
Fig. 16.16 Left sided raphe deviation with hypospadias
16. 2 Significance of GMR Anomalies

110
Fig. 16.18 Median raphe
deviation with intact
prepuce
Fig. 16.19 Same case in Fig. 16.18 after preputial retrac-
tion with a megameatus anomaly
Fig. 16.17 Right sided deviation with hypospadias
16 Median Genital Raphe Anomalies

111
16.2.8 A Bucket Handle
Malformation (Fig. 16.20)
It is a prominent median perineal raphe with a
space separating it from the skin, which is com-
monly seen in different types of anorectal malfor-
mations, and used earlier to differentiate between
high and low anomalies, but this clinical feature
may be seen in perineal fistula as a prominent
midline skin bridge or a subepithelial midline
raphe fistula that looks like a black ribbon
because it is full of meconium. These features are
externally visible and help in diagnose of peri-
neal fistula [9].
16.2.9 Median Raphe Cyst (MRC)
(Fig. 16.21)
These cysts are due to tegumentary formation
that arises as a result of “tissue trapping” during
midline fusion of the ectoderm. Such anomalies
could be simple skin pathology or might repre-
sent major abnormalities like hypospadias or
other urethral anomalies.
Ectodermal canals involving part or all of the
raphe had been reported for the first time at
1924 by Rupel E, and it is considered as an
extension of multiple raphe cysts with the same
pathology [10].
Fig. 16.20 Bucket handle malformation Fig. 16.21 Median Raphe Cyst
16. 2 Significance of GMR Anomalies

112
The diagnosis of median raphe cyst is difficult,
but needs to be differentiated from other condi-
tions such as epidermal cyst, steatocystoma, glo-
mus tumor, dermoid cyst, urethral diverticulum,
and pilonidal cyst when it presents in the penile
(most common site) and scrotal region. There is
little need of confusing these with sebaceous
cysts. Common pyogenic infections as well as
specific venereal and acid-fast infections must be
considered, and there is no explanation why these
cysts are vulnerable to gonorrhoea infection either
as an isolated cyst infection or along urethral
affection, it was reported earlier by Rupel [10].
In the usual examination of the genitals the
median raphe gets little attention. With the pos-
sibility of cysts and canals of the raphe kept in
mind it is likely that many of these lesions would
be discovered. Most MRCs are asymptomatic in
childhood and become symptomatic as the child
grows, swelling tenderness and purulent dis-
charge can be seen when cysts become trauma-
tized and secondarily infected.
Most commonly, the diagnosis of median
raphe cyst is established postoperatively on histo-
logical and immunohistochemical studies. The
epithelial lining of median raphe cyst includes
columnar stratified, pseudostratified, or squamous
cells, correlating with histology in different por-
tions of male urethra, but rare cases containing
ciliated cells in epithelium had been reported [11].
Three different theories have been proposed
for pathogenesis of median raphe cyst:
1. Developmental from urethral remnants due to
a defect in the fusion of urethral folds.
2. Developmental implant of the ectopic periure-
thral glands of Littre’ that are usually located
in the rectal portion of the urethra.
3. Anomalous formation of epithelial buds from
the urethral columnar epithelium, followed by
separation.
16.2.10 Beaded Median Raphe
(Fig. 16.22)
Rare cases of brown fine darker nodules replac-
ing the normal line of median raphe had been
reported, and this could be a normal variant, or
a variant of penile cyst with the same pathology
and etiology, we detected 2 cases in association
with anorectal malformation. Nothing surgical
is required for such cases, only through exami-
nation to rule out any associated anomalies,
family assurance and follow up. Other congeni-
tal abnormalities such as blind-ending canals
opening onto the penile surface must be
differentiated.
Fig. 16.22 Beaded median raphe
16 Median Genital Raphe Anomalies

113
16.2.11 Pearly Penile Papules
(Fig. 16.23)
Pearls of meconium can be seen on the raphe of
the scrotum and are considered to be a sign of
low presentation of an anorectal malformation.
Scrotal pearls without an anorectal malforma-
tion, which are usually whitish in colour, are very
rare in infants and designated as median raphe
cyst (MRC) of the perineum [12]. It may also
considered as a minute inclusion cysts.
Conclusion
Thorough examination of infants presented
for routine circumcision could be beneficial
for surgeons in detecting many anomalies
which are thought to be rare but actually may
not be, as well as for the patients to find out
any hidden anomalies. Genital median raphe
anomalies may not be so rare as thought, as
they were present in about 2 % of the neonates
with a wide spectrum of variability, and they
could hide an associated serious genitourinary
anomaly. Any infant with an abnormal genital
median raphe should be investigated to detect
such anomalies, and neonatal circumcision
should be postponed in such cases.
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Fig. 16.23 Pearly penile papules
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16 Median Genital Raphe Anomalies