EURURO Vol. 71 No. 5

793 844

16.7–40.8) for extravesical deep peritoneal endometriosis.
The presence of at least one of these was documented in
87.9% of cases (95% CI 76.7–94.3), supporting the notion
that BE nodules should not be considered an independent
form of the disease, but rather another manifestation of
endometrial cell dissemination in the pelvis .
The basis for considering BE as an independent
pathogenetic form of the disease arises from the idea that
it indeed represents adenomyosis originating from meta-
plasia of Mu¨ llerian remnants and/or extension of adeno-
myotic lesions arising in the myometrium. The observation
that these lesions are histologically characterized by dense
tissue composed of fibrous and smooth muscle cells with
islands or strains of glands and stroma supports this view
. On anatomopathologic grounds, these nodules are
thus more reminiscent of adenomyosis than of endometri-
osis. However, there are some converse arguments to this
theory: (1) histologic evidence documenting the presence of
embryologic remnants within the uterine-vesical area has
never been provided; (2) it has been shown that smooth
muscle cells are present in all endometriotic lesion types
; (3) in most series published, no adenomyotic nodules
of the uterine wall were found in association with BE
, making the uterine adenomyosis extension theory
unlikely. Thus, while the metaplasia theory has lost
reliability over time, it should be noted that of the 11 cases
of male endometriosis reported in the literature ,
four developed endometriosis of the bladder concomitant
with high estrogen exposure Mu¨ llerian duct
remnant metaplasia may consistently apply to these cases,
with the location of the nodules along the route of the
Mu¨ llerian ducts, namely the verumontanum, trigone,
ureterovesical junction, lateral wall of the bladder, and
paratesticular region. Interestingly, probably because of its
rarity compared to other forms of the disease, no studies
have addressed pathogenetic features of BE, including
proliferation activity, apoptosis status, inflammatory char-
acteristics, and neuroangiogenesis capacity.
3.1.2. Association with surgical procedures
An iatrogenic form of BE has long been proposed and it
has been suggested that it arises from intraoperative
dissemination of endometrial cells, as well as disruption
of the uterine incision, even after many years. As early as
1960, Abeshouse and Abeshouse pointed out that 39 out
of 56 patients affected by bladder endometriosis had
undergone a gynecologic or surgical procedure, which
underlined the importance of an accurate operative
technique to avoid iatrogenic dissemination. The frequency
of caesarean section among women with BE has been
reported as 15% (95% CI 8.3–26.9] , but the association
between BE and the surgical procedure is not consistently
recognized . In particular, a very recent cross-sectional
study including a consistent number of BE women found
that the incidence of isolated BE was similar between
patients with (37.5%) and without (41.7%; p = 0.6) a history
of uterine surgery. In addition, BE severity and the anatomic
distribution of associated DIE lesions, including vaginal,
intestinal, and ureteral involvements, did not differ
between the two study groups Overall, these
observations indicate that there is still a need for further
clarification of the existence of two BE entities after prior
uterine surgery.
3.2. Diagnosis of BE
3.2.1. Clinical history and examination
A woman of reproductive age complaining of pain
symptoms (dysmenorrhea, dyspareunia, and nonmenstrual
pelvic pain) is at risk of DIE . Some studies reported
that DIE is associated with lower urinary symptoms (LUTS);
however, the prevalence of this association is unclear
ranging between 2% and 77% According to the
findings of a recent research, no difference was reported in
the rate of urgency, urinary frequency, voiding symptoms
and bladder pain between patient with posterior endome-
triosis plus BE compared with those with posterior
endometriosis only . Dysuria, frequency, bladder pain,
and, less commonly, hematuria, urgency, and urinary
incontinence are symptoms related to the presence of BE
. Dysuria has been reported in 21–69% of
patients with BE and positive correlation was
observed between severity and lesion diameter . Hema-
turia is a less frequent symptom, reported in 0–35% of the
cases this is explained by the fact that the bladder
lesion rarely infiltrates the mucosal layer.
Vaginal examination is a critical part of the evaluation of
women with suspected DIE, and is highly reliable ,
particularly in detecting BE, for which the accuracy is nearly
100% . Physical examination allows identification of
a palpable nodule or a thickened area along the anterior
vaginal wall that may be painful in 35.7–100% of patients
).
Symptoms related to BE are common to several urologic
conditions such as recurrent cystitis–overactive bladder,
bladder carcinoma, interstitial cystitis/bladder pain syn-
drome, and chronic urethral syndrome. Women of repro-
ductive age complaining of LUTS, particularly in
combination with pain symptoms and/or positive anterior
vaginal examination, should be always considered for a
diagnosis of BE and further investigated via imaging
techniques (ultrasonography and magnetic resonance
imaging [MRI]).
3.2.2. Endometriosis and interstitial cystitis/bladder pain syndrome
Interstitial cystitis/bladder pain syndrome (BPS) is defined
as symptoms of chronic pelvic pain (CPP), pressure, or
discomfort perceived to be related to the urinary bladder
accompanied by at least one other urinary symptom such as
a persistent urge to void or frequency in the absence of any
identifiable pathology or infection . Endometriosis
(including BE) and BPS share similar symptoms, and are
both causes of CPP. Several studies have shown coexistence
(16–78%) of these two conditions defined by Chung
et al as ‘‘evil twin syndrome’’. Panel et al
investigated the characteristics of LUTS and urodynamic
findings for patients with posterior endometriosis versus
those with a posterior location and BE. Interestingly, the
E U R O P E A N U R O L O G Y 7 1 ( 2 0 1 7 ) 7 9 0 – 8 0 7 793