Myometrial involvement of tumor-like cystic endosalpingiosis: a rare entity



Endosalpingiosis is characterized by the presence of benign glands lined by tubal-type epithelium involving the pelvic and lower abdominal peritoneum and pelvic and para-aortic lymph nodes in women. Rarely, cystification can occur, resulting in a neoplasm-like mass associated with clinical manifestations, an intraoperative abnormality, or a striking finding on gross examination. Here we report the transvaginal ultrasound, magnetic resonance imaging and histopathological appearance of an unusual case of cystic endosalpingiosis involving the right ovary and full thickness of the wall of the uterine fundus in a patient who presented with a 6-month history of menorrhagia and pelvic pain. Clinicians should be aware of this type of uterine benign manifestation so as to refrain from overtreatment. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.

Case Report

A 45-year-old woman, gravida 2 para 2, presented with a 6-month history of menorrhagia and pelvic pain. She had had continuous vaginal bleeding for the previous 2 months, which did not respond to the prescribed progesterone pills, and was referred to us. Her vaginal examination was normal except for an enlarged uterus and vaginal bleeding from the cervical ostium. Transvaginal ultrasound examination revealed a 35 × 30-mm intramural cystic mass in the fundus, extending from the fundal end of the endometrial lining into the myometrium (Figure 1), and a 30 × 30-mm right ovarian cyst. The cysts were unilocular and anechoic with smooth internal walls on B-mode imaging and no flow on color Doppler imaging according to the International Ovarian Tumor Analysis definitions1. The myometrium was heterogeneous, containing adenomyotic foci, and the myometrial mass was therefore thought to be cystic adenomyosis. Magnetic resonance imaging (MRI) revealed an intramural hyperintense cystic lesion in the right ovary and in the uterine fundus, the lesion in the latter being adjacent to the endometrium (Figure 2). The cystic mass was not consistent with a diagnosis of cystic adenomyosis because the measurement of the junctional zone was within normal limits and there was no blood signal within the cyst in T1- and T2-weighted images.

Figure 1.

Transvaginal ultrasound image of the uterus showing an intramural, unilocular and anechoic cystic mass (thick arrow) with smooth internal walls localized to the uterine fundus. The thin arrow indicates the endometrium.

Figure 2.

T2-weighted magnetic resonance image of the abdomen showing the intramural hyperintense cystic lesion (thick arrow) in the uterine fundus adjacent to the endometrium (thin arrow).

Laparotomy revealed a simple cystic structure in the right ovary and an enlarged uterus. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. On the cut surface of the uterus, the lesion was a well circumscribed, intramural, serous fluid-filled cystic mass in the uterine fundus having continuity with the endometrium (Figure 3). On microscopic examination, the cystic masses in the myometrium and the right ovary were seen to be lined by tubal-type epithelium consistent with the diagnosis of cystic endosalpingiosis. There were multiple cysts in the cervix, close to the endocervix, and in the serosal surface and parenchyma of both ovaries, which were also lined by tubal-type epithelium (Figure 4).

Figure 3.

Cut surface of cystic endosalpingiosis involving the myometrium (thick arrow) and adjacent to the endometrium (thin arrow).

Figure 4.

Histological sections of cystic endosalpingiosis (arrows) involving: the myometrium (a; hematoxylin and eosin (H & E) stain, original magnification × 400); the cervix (b; H & E, original magnification × 40); the right ovary (c; H & E, original magnification × 40); and the left ovary (d; H & E, original magnification × 100).


Endosalpingiosis is a non-neoplastic process and is generally considered to be derived from the secondary Müllerian system, which consists of structures covering the peritoneal mesothelium, the adjacent mesenchyme in the small pelvis and the lower part of the female abdominal cavity2. Proliferation of these structures can result in the creation of three different types of lesions: endometriosis, which occurs most frequently, and the less common endosalpingiosis and endocervicosis3.

Endosalpingiosis was first described by Sampson in his study of the stumps of patients after tubal sterilization or previous salpingectomy4. It is almost always an incidental finding, either at the time of operation or, more commonly, on microscopic examination5. It is most commonly encountered on the pelvic peritoneum covering the uterus, Fallopian tubes, ovaries and cul-de-sac. Less frequent sites include the pelvic parietal peritoneum, omentum, bladder and bowel serosa, para-aortic area and skin5. Only a few examples of tumor-like cystic endosalpingiosis localized to the female pelvis have been described, and most of these cases are reported to be derived from the serosal surface of the uterus and the ovary6–10 or from the paraovarian region11. There have only been four cases previously reported in the literature of tumor-like cystic endosalpingiosis resulting in grossly apparent transmural cysts of the uterus2, 3, 12 (Table 1); our report is the fifth. In the case presented here, there was microscopically detected endosalpingiosis in the cervix and both ovaries as well as the tumor-like cystic endosalpingiosis in the right ovary and in the myometrium. Our case is similar to that described by Clement and Young2 in that the cystic mass in the myometrium showed continuity with the endometrium.

Table 1. Summary of pelvic tumor-like cystic endosalpingiosis cases reported in the literature
ReferencePatient's age (years)Clinical presentation related to the lesion and preoperative diagnosisLocationGross findings
Bryce et al. (1982)825Incidental finding on Cesarean section at termAnterior uterine serosa and uterovesical foldContinuous multicystic lesion composed of endosalpingiotic cysts measuring up to 1 cm
Clement & Young (1999)241Menometrorrhagia and dyspareunia; orange sized mass in the lower  uterine segment  consistent with uterine  leiomyomaCervix, lower uterine segment, lower corpus (involving the myometrium, serosa or paracervical connective tissue, one focus extending into the endometrium)Numerous cysts resulting in a spongy appearance
Clement & Young (1999)243Menometrorrhagia, pelvic pain and enlarged cervix; multiple uterine cysts on  ultrasoundCervix, lower uterine segment, lower corpus (involving the myometrium, serosa or paracervical connective tissue)Multiple cysts measuring up to 3.2 cm
McCluggage & Weir (2000)948Incidental finding at laparatomy for endometrial polypsRight paraovarian cystUnilocular cyst measuring 2.5 cm
Chang et al. (2003)1045Abdominal dull pain and irregular menstruation; multilobular mass with  filmy septa and  homogeneous cystic  content behind the uterus  in the pelvic cavity on  ultrasoundPedunculated uterine mass originating from the uterine serosaMultilobular cyst measuring 8.2 × 7.5 × 6.0 cm
Heatley and Russell (2001)673Lower abdominal swelling; unilocular ovarian cyst (proved to be benign serous ovarian cyst)Beneath the uterine serosa within the superficial myometrium extended from the mid corpus to the cervix and adjacent parametriumCystic spaces and nodules measuring up to 16 mm
Fukunaga (2004)751Lower abdominal pain; cystic ovarian tumorSubserosal sessile polypoid mass in the anterior fundusMass with cysts measuring up to 4 cm
Lee et al. (2005)1152Accidentally detected cystic ovarian tumorTwo cysts attached to the posterior fundal serosa of the uterus with narrow stalksThin walled unilateral and multilocular cysts measuring 13 cm and  8.5 cm
Kajo et al. (2005)350Palpable tumoral mass; adnexal tumorUterine fundus (intramural)Tumor-shaped configuration of fundus with a diameter of 4.5 cm
Youssef et al. (2006)1249MenorrhagiaPedunculated tumoral mass on the anterolateral aspect of the uterine corpus and multiple cysts of different sizes on the serosal surface of the uterine corpus and both ovariesMultiple cysts measuring up to 20 mm
Present case (2007)45Metrorrhagia and pelvic pain; unilocular uterine fundal cystic massUterine fundus (intramural extending to endome- trium) and serosal surface of the right ovaryUnilocular intramural cyst measuring 3.5 cm and right ovarian cyst measuring 3 cm

The pathological differential diagnosis of endosalpingiosis is discussed in detail in previously reported cases2, 6, 7, 12. However, the clinical differential diagnosis of an intramural mass, whether it causes any symptoms or not, is more important for clinicians when discussing further surgery with the patient. Therefore the symptoms and the imaging findings of this rare entity are very important.

We discussed the management of this symptomatic uterine mass with our patient based on her age, the continuous bleeding that did not respond to medication and the unknown etiology of the intramural cystic mass in the uterus, and decided to perform total abdominal hysterectomy and bilateral salpingo-oophorectomy. After the transvaginal ultrasound scan our initial diagnosis was either a degenerative leiomyoma or a cystic adenomyosis. However, the diagnosis was challenging because of the purely cystic nature without any hyperechogenicity. A literature search using the keywords ‘intramural cyst’ and ‘myometrial cyst’ directed us to cystic adenomyosis, but MRI supported neither degenerative myoma nor adenomyosis, as the measurement of the junctional zone was within normal limits and there was no blood signal within the cyst in T1- and T2-weighted images.

In a recently published case report of a 13-year-old girl with a cystic myometrial lesion, ultrasound examination revealed a thick-walled, isolated 3-cm mass in the myometrium, containing a fluid level, which was suspected to be cystic adenomyosis on ultrasound and MRI findings13. On MRI and ultrasound imaging cystic adenomyosis appears as a myometrial mass with a slightly hyperechoic thick wall and a central, hemorrhagic cystic portion with a surrounding hypointense component13, 14. Our case did not show any hemorrhagic foci or a surrounding hypointense component, as is usual in cases of adenomyosis.

Leiomyomas with cystic degeneration show high signal intensity on T2-weighted images, and the cystic areas do not enhance15. The ultrasound appearance of a cystic degeneration of a leiomyoma shows hyperechoic foci or heterogeneous appearance, indicative of the degeneration process.

Excluding cystic degeneration of uterine leiomyoma, intramyometrial cysts are rare. Their usual differential diagnosis includes congenital uterine cysts such as mesonephric and paramesonephric, cervical nabothian cyst, and intramyometrial hydrosalpinx. All of these lesions are cysts filled with simple fluid and are not surrounded by a solid component as in our case14. However, because of the location of the myometrial cyst in our case none of these was included in our differential diagnosis.

It must be kept in mind that cystic uterine lesions that do not have the classical appearance of cystic adenomyosis or leiomyoma on ultrasound examination may be a type of benign non-tumorous lesion such as cystic endosalpingiosis, which can occasionally resemble a neoplasm of uncertain biological behavior. This possibility must be considered in the differential diagnostic spectrum of uterine lesions, thus avoiding the problem of overtreatment of dysfunctional uterine bleeding.