Keywords anorectal malformation - cloaca - external genitalia - ambiguous genitalia
Introduction
Cloacal malformations involve a wide spectrum of anomalies of the lower genitourinary
and colorectal tract, with different prognosis in terms of urinary, bowel, and sexual
function, as well as quality of life. Establishing the correct diagnosis of persistent
cloaca can sometimes represent a difficult task, because the classic appearance of
a single perineal orifice with female external genitalia will not be evident.[1 ]
Posterior cloaca (PC) is a unique defect in which the urethra and the vagina fuse
together into a urogenital sinus that deviates posteriorly and opens into the anterior
rectal wall or immediately anterior to the anus. Typically, in this defect, the anus
is correctly located and also has a pectinate line.[2 ]
Independently on the type or prognosis, it is known that cloacal malformations are
associated with anatomic variations of the external genitalia including hypoplasia
of the labia minora and enlarged clitoris. Bischoff et al published that patients
with more complex cloacal malformation such as patients with longer common channels
have a greater chance of presenting with these anatomical variations.[3 ] These variations may lead to incorrect diagnosis such as a “disorder of sex development”
previously referred as “ambiguous genitalia” or “intersex.” Overall, it is estimated
that the incidence of female pseudohermaphroditism misdiagnosis in patients with cloacal
malformation is approximately 7 to 18%[3 ]
[4 ]; in the particular case of PC, the association appears to be even more common.[3 ]
These anatomical variations lead to questioning these females' gender, parental stress,
and carrying unnecessary testing or/and surgical procedures. However, a meticulous
palpation of the “phallic-appearing” structure would allow the clinician to confirm
that there is only redundant skin and no palpable corpora, unlike in patients with
congenital adrenal hyperplasia, where the clitoris is hypertrophied from excess of
adrenal androgens and therefore will result enlarged, with palpable corpora or erectile
tissue.[3 ]
Having this in mind, we aimed to investigate the presence of ambiguous genitalia in
utero or at birth in patients specifically with PC in the literature. Parallelly,
we analyzed the ARM-Net Consortium registry to find patients with PC, focusing on
the description of the genitalia, gender assignment, and its consequences.
Material and Methods
A systematic literature search was conducted by two independent researchers in November
2022 using the PubMed, EMbase, and Web-of-Science databases. Studies in English were
searched in PubMed using the following search terms: (cloaca[mesh] NOT enterobacter[mesh])
OR anus, imperforate[mesh]) AND posterior OR variant OR sinus (surger*[tw] OR surgic*[tw]
OR operat*[tw] OR reconstruct*[tw]) AND (gender*[tw] OR genitalia*[tw] OR ((cloaca*[tw]
OR anus*[tw] OR anal[tw] OR anorect*[tw] OR urorectal*[tw] OR rectal*[tw] OR rectum*[tw]
OR urogenit*[tw] OR urologic*[tw] OR vagina*[tw]) AND (malform*[tw] OR abnormal*[tw]
OR imperforat*[tw]) AND (surger*[tw] OR surgic*[tw] NOT (animals[mesh] NOT humans[mesh])
NOT medline[sb]).
For the other databases similar search terms were conducted which included all the
publications describing patients with PC. We selected articles according to their
title and abstracts for revision. Both researchers read the selected articles in full
and analyzed them. Occasional divergence in selection was resolved by consensus (i.e.,
some articles did not describe properly the anatomy and was difficult to differentiate
urogenital sinus from PC). Upon reading the articles, we performed a secondary search
with the selection of articles from the bibliography contained in the primary documents
of the previous search.
The ARM-Net Consortium is a group of European professionals including pediatric surgeons,
epidemiologists, geneticists, and patient advocacy groups, that was established in
2010.[5 ] The aim of ARM-Net Consortium is to collect data and exchange knowledge, by promoting
research on anorectal malformations (ARMs) to improve clinical care and quality of
life of ARM patients.
The ARM-Net Consortium established the ARM-Net patient registry where data are included
prospectively for patients born from 2011, and retrospectively for patients born from
2007 till 2011. This project of dedicated volunteers has successfully registered more
than 2,600 ARM patients across Europe.
By November 2022 ARM-Net Consortium members and steering committee were reached out
to ask for permission to search through the registry to identify all the patients
classified as PC. Once the patients were identified, we contacted the ARM-Net members
who included patients into the database via e-mail to ask whether they wanted to participate
in the project. After agreement to participate was obtained, they were asked to collect
further clinical data. Data were exported for analysis, creating an Excel database
and stored according to the Data Protection Act. Results are reported using descriptive
statistics.
Results
ARM-Net Registry Research
Until end of February 2023, a total of 2,619 patients were included in the ARM-Net
registry. Nine patients in the registry (0.3%) were reported to have PC ([Table 1 ]).
Table 1
Patients with PC identified in the ARM-Net registry
Patients
1
2
3
4
5
6
7
8
9
Prenatal diagnosis and interventions
Prenatal diagnosis
x
x
x
x
x
x
x
Cystic pelvic mass
x
x
x
x
Bilateral hydronephrosis
x
x
x
Megacystis
x
x
Ambiguous genitalia
x
x
Male genitalia
x
x
Fetal ascitis
x
x
Oligohydramnios
x
x
x
Colonic dilation
x
Prenatal MRI
x
x
Amniocentesis
x
x
x
Fetal surgery (vesicoamniotic shunt)
x
Perinatal examination and study
Gestational age (in wk)
34
33
38
34
NR
32
NR
32
36
Physical examination at birth
Single posterior perineal orifice
x
x
x
x
x
x
x
Posterior perineal orifice with accessory atretic urethra
x
x
Ambiguous genitalia
x
x
x
x
x
x
x
“Male” genitalia
x
x
Severe abdominal distension
x
Acute kidney failure
x
x
Female sex assignment
x
x
x
x
x
x
x
Neonatal intervention
Colostomy
x
x
x
x
x
x
x
Vesicostomy
x
x
x
x
x
Vaginostomy
x
x
x
Vaginal septum division and drainage
x
x
Hormonal and endocrine study
Thyroid function
x
x
x
x
Androgens
x
x
x
x
x
Array CGH
x
x
Definitive repair
Transrectal urogenital mobilization
x
x
x
x
x
Age at definitive repair (in mo)
10
12
3
11
NR
6
6
NY
24
Abbreviations: CGH, comparative genomic hybridization; MRI, magnetic resonance imaging;
NR, not reported; NY, not yet corrected; PC, posterior cloaca.
Patients were born between the years 2010 and 2022. Median maternal age was 29 years
(27–49). Seven (78%) had prenatal diagnosis of an abnormality: pelvic mass (N = 4), bilateral hydronephrosis (N = 3), megacystis (N = 2), and fetal ascites (N = 3). Two patients had fetal imaging performed (magnetic resonance imaging [MRI];
patients 2 and 4).
Of our cohort, five patients (56%) were diagnosed with ambiguous genitalia (patients
1, 2, 3, 8, and 9), either pre- or postnatally, and two (patients 4 and 7) were assigned
with male gender at birth. [Fig. 1 ] shows the appearance of the external genitalia of one of the patients described
as having ambiguous genitalia.
Fig. 1 Patient with posterior cloaca (PC) diagnosed with ambiguous genitalia pre- and postnatally.
Hormonal and karyotype studies were performed and she was then assigned as female.
All these patients were intensively investigated, namely, with endocrine and hormonal
studies and karyotype. Of the patients identified as males, patient 4 had a prenatally
diagnosed cystic pelvic mass, bilateral hydronephrosis, polyhydramnios, and fetal
hydrops. A fetal MRI was obtained, identifying a cystic pelvic mass of 72 × 75 × 87 mm,
a caudal cyst of 20 × 17 × 25 mm, bilateral hydronephrosis, bladder compression, and
polyhydramnios. At birth, this patient was assigned as male, based on external genitalia
examination. The patient required high-frequency oscillatory ventilation due to massive
abdominal distension that caused severe respiratory distress. Urgent laparotomy was
required, an intraoperative biopsy of the mass reported the diagnosis of “teratoma”
and the cystic mass was therefore removed. The postoperative definitive pathology
reported the cystic mass as uterine body with dilated vaginal cavity, together with
ovarian tissue. Subsequent karyotype confirmed female gender (46, XX). Patient 7 was
born and given male gender based on physical examination; after extensive investigation,
karyotype was consistent with female gender.
Only two patients (patients 5 and 6) were correctly assigned as females and diagnosed
with PC with respective variations of external genitalia.
Systematic Review
After revision of our search (see [Fig. 2 ]), a total of 14 articles with case reports of patients with PC were identified,
encompassing a total of 60 patients ([Table 2 ]).[1 ]
[2 ]
[6 ]
[7 ]
[8 ]
[9 ]
[10 ]
[11 ]
[12 ]
[13 ]
[14 ]
[15 ]
[16 ]
[17 ]
Fig. 2 Systematic review search flow.
Table 2
Systematic review of PC patients
Reference
N
External genitalia description
Posterior cloaca with accessory urethra[7 ]
1 patient
Clitoromegaly
Posterior cloaca—further experience and guidelines for the treatment of an unusual
anorectal malformation[2 ]
29 patients
No mention to genitalia
Posterior cloaca: a rare subtype of a complex anorectal malformation[8 ]
1 patient
Ambiguous genitalia; late diagnosis
Posterior cloaca: a unique defect[9 ]
9 patients[a ]
No mention to genitalia
Posterior cloaca: a urogenital rather than anorectal anomaly[10 ]
7 patients
5 patients with ambiguous genitalia, of which 2 had clitoromegaly
Posterior cloaca variant with clitorolabial transposition and a rectoperineal fistula[12 ]
1 patient
Clitorolabial transposition
Rare association of female pseudohermaphroditism, phallic urethra and posterior cloaca[13 ]
1 patient
Ambiguous genitalia
A unique defect – persistent posterior cloaca: An example of staged genito-urinary
and digestive tract reconstruction with an alternative vaginal creation using the
urinary bladder wall[15 ]
1 patient
No external genitalia
An unusual case of type a posterior cloaca associated with 46xx disorder of sexual
differentiation with y duplication of urethra[16 ]
1 patient
Ambiguous genitalia
Unusual variety of posterior cloaca[17 ]
2 patients
No mention to genitalia
Posterior cloaca: multicenter experience of a very rare and unusual anorectal and
genitourinary malformation[11 ]
4 patients
3 patients with ambiguous genitalia
Reverse (posterior) cloaca with congenital rectal stenosis and pseudohermaphroditism:
a rare entity with rare association[14 ]
1 patient
Ambiguous genitalia
Newborn with persistent cloaca presenting with accessory phallic urethra and ambiguous
genitalia[1 ]
1 patient
Ambiguous genitalia
Duplication of accessory phallic urethra (urethra triplication) in the female, signaling
mesenchymal interruptions of the cloacal membrane as a cause for sagittal urethral
duplications[6 ]
1 patient, demised soon after birth
Ambiguous genitalia
Abbreviation: PC, posterior cloaca.
Note: A total of 60 patients were identified.
a Two articles from Peña et al were included, with two groups of posterior cloaca patients;
we assumed they were different patient groups.
Of these patients, only 20 (33%) had descriptions of the external genitalia; 14 (23%)
had anatomical variations described as with ambiguous genitalia, 1 had clitorolabial
transposition, and 1 had underdeveloped vulva and vagina. Only four patients (7%)
had normal female anatomy. In this review, in 8 out of the 14 case reports, patients
had extensive analytical investigation, namely, with karyotype definition and hormonal
studies, all revealing 46, XX female patients with no hormonal abnormalities.
Discussion
In the current study, we present a systematic review on PC with special emphasis on
the reported findings of ambiguous genitalia and the consequences of this misdiagnosis
in female patients with PC; this came after we realized how common it appears to incorrectly
diagnose these patients and conduct unnecessary tests, sometimes invasive ones, for
expected anomalies associated with PC.
After our ARM-Net registry revision, nine patients were identified. As we previously
described, more than half had genital anomalies, and two patients were wrongly assigned
as males.
The first description of PC was published by Peña and Kessler in 1998[9 ] and it represents a rare variant of cloacal anomaly with only 60 cases reported
in the literature.[1 ]
[2 ]
[6 ]
[7 ]
[8 ]
[9 ]
[10 ]
[11 ]
[12 ]
[13 ]
[14 ]
[15 ]
[16 ]
[17 ] Opposing classic cloaca, where a single perineal orifice is located at the urethral
situs, draining the fusion of the urethra, vagina, and rectum, in PC the urogenital
sinus is posteriorly deviated, opening in the anterior rectal wall, which is normally
located or slightly anterior to the sphincter complex.[2 ]
[8 ]
[9 ]
[18 ] However, differences between classic cloaca and PC go beyond anatomy; it has been
described by Peña that there is a greater association of both hydrocolpos (65 vs.
25%) and urological malformations (93 vs. 59–91%) compared with classic cloaca, even
in cases of long common channel.[2 ] In the case of genital abnormalities, it is no exception, and genital ambiguity
appears to be more common in PC than in other cloacal variants.[3 ] The first description of genital anomalies and phallus-like in cloaca girls or patients
with urogenital sinus defects was by Broster in 1956.[19 ] In the literature, many papers do not describe these anatomical variations (only
20/60 patients had anatomical genital descriptions); however, in the small number
where a description is made, a very significant proportion of anatomical genital variations
is reported, with 14/20 described with ambiguous genitalia or other variations. In
our revision of the ARM-Net registry, we found that 55% of PC girls had some form
of ambiguous genitalia. This comes in line with our notion that in PC the incidence
of genital abnormalities is very high, even higher than in other cloacal anomalies.
This had been previously noted by Bischoff et al, where 21% of cloaca patients with
misdiagnosis of disorders of sexual development had PC variant, a percentage which
largely surpasses the 4% of PC incidence in their study.[3 ] Other studies had described the incidence of this pseudohermaphroditism in cloaca
patients of around 7.4%[4 ]; again, in PC it appears to be higher.
As we can infer from normal karyotype and hormonal studies, genital anomalies in cloaca
patients are not hormonal-mediated and there are some theories explaining these genital
variations. McMullin and Hutson suggested that masculinization of the external genitalia
is secondary to fundamental derangement of urogenital development, where the early
perineal anomaly permits an independent phallic growth and genital folds fusion, independently
of androgen control.[20 ]
As described by Karlin et al, these phallus-like structures do not contain developed
corpora cavernosa and the urethra may be absent, very narrow, and hypoplastic or near
normal. This canal may represent the common cloacal channel, the urethrovaginal channel,
or an accessory opening into the malformation.[4 ]
[21 ] A careful physical examination at birth is sufficient to differentiate these girls
from disorders of sexual development, as in cloacas the phallus-like structure is
represented only by excess clitoral skin, with an absence of penile erectile components.[3 ]
As we realized from our cohort, unawareness of this condition may lead to disastrous
situations. In cases of PC, a careful physical examination is sufficient to diagnose
and lead the necessary investigations and surgical procedures. It was almost global
that these patients had intense endocrinological and genetical testing, as they were
probably studied as disorders of sexual development. From previous reports, we know
that cloacas are not associated with disorders of sexual development and should not
be studied as such.[3 ]
This invasive and expensive testing, not exempt from possible complications for the
patients, only feeds high level of parental stress and uncertainty, with no advantage
for the patients' care.
Conclusion
PC is a rare subtype of cloacal malformation, with only 60 cases reported in the literature,
and is the subtype mostly associated with genital anomalies. For this reason, patients
with PC are at risk of misdiagnosis of ambiguous genitalia, disorders of sexual development,
or even wrongful gender assignment. In the ARM-Net database, of the nine PC patients,
two were assigned as males; after this misdiagnosis, one of them suffered mutilating
surgery with unaware salpingo-oophorectomy, hysterectomy, and vaginectomy. With a
high suspect index together with a careful physical examination, this is avoidable
and a correct diagnosis is possible, preventing all the unnecessary and possibly harmful
testing and surgical procedures.
