U-turn of uterine arteries: a novel sign pathognomonic of uterine inversion

Abstract

A uterine inversion occurs when the uterine fundus collapses into the endometrial cavity. It is a rare complication in obstetrics following delivery, and it is even more infrequently encountered in gynecology with the non-puerperal uterus. A submucous fibroid is the most common reported cause of the non-puerperal uterine inversion. If not promptly recognized and treated, uterine inversion may lead to a severe hemorrhagic shock and death. We describe a novel three-dimensional power Doppler feature for the diagnosis of uterine inversion.

Case report

A 75-year-old woman, presented with a chief complaint of malodorous vaginal mass and vaginal bleeding with a mass protruding through her vagina.

Upon admission, on pelvic examination, a necrotic mass, 15 cm in diameter, protruding through the cervix and occupying the vagina was observed.

Transvaginal ultrasound demonstrated a big solid mass connected to the uterus by peduncle of 1.5 cm. The initial assessment diagnosis was of a pedunculated prolapsed fibroid. The large size of the fibroid mass made it difficult to accurately demonstrate the uterus using the transvaginal ultrasound.

During the following day, the patient underwent a transvaginal excision of the mass.

On the day after the excision of the necrotic fibroid, the patient was taken for a repeat ultrasound follow-up to examine the pelvic cavity especially the uterus which was not demonstrated properly with the mass in place.

An ultrasound follow-up exam (GE Voluson 730 expert) with the vaginal probe applied directly to the uterine corpus, with 3D power Doppler—showed—bilateral uterine arteries in a longitudinal central location along the uterine body, with a U-turn sign, showing a central course of the main uterine vessels (Fig. 1) instead of their normal anatomical peripheral location laterally alongside the corpus of the uterus (Fig. 2).

Fig. 1.

Transvaginal 3D power Doppler image in the coronal plane of a normal non-puerperal uterus with uterine blood vessels passing laterally to the uterine corpus (arrows). Fn fundus, Cx uterine cervix

Fig. 2.

Transvaginal 3D power Doppler image in the coronal plane of an inverted non-puerperal uterus. Uterine blood vessels passing centrally to the inverted uterine fundus (arrows). Fn the inverted fundus in direct contact with the vaginal probe. Cx original position of the uterine cervix. Vg anterior vaginal wall

This diagnosis of uterine inversion was later confirmed during her subsequent surgery for abdominal hysterectomy (Fig. 3). Gross pathology specimen (Fig. 4) later was confirmed as a benign fibroid tumor.

Fig. 3.

Image of an inverted uterus seen during laparotomy before an abdominal hysterectomy. Anterior position (yellow arrow) and Posterior (green arrow)

Fig. 4.

Gross pathology specimen of the inverted uterus with a tumor in the fundal part. Black arrows marking the cervix, fundus and tumor

Discussion

Non-puerperal uterine inversion is an extremely rare medical condition. It is almost always associated with the presence of a polypoid uterine tumor, or a submucous fibroid, but other tumors (e.g., teratoma, uterine sarcoma) have also been implicated [1–5].

On reviewing the available literature, there are several clinical and sonographic signs that might drive the clinician to suspect the diagnosis of uterine inversion. First is the combination of the presenting symptoms of malodorous vaginal discharge and uterine bleeding and a bimanual pelvic examination with failure to palpate the uterine fundus. The diagnosis might be more straightforward to suspect in cases of a complete inversion.

The reported sonographic features include a Y-shaped configuration caused by the invaginated fundus further displacing the two opposing uterine walls in the longitudinal plane. An X-shaped hypoechoic center made by endometrial folds. A hyperechoic mass in the vagina with a central hypoechoic H-shaped cavity in the transverse image [6–9]. Another image is when the uterus appears as a “target sign” with a hyperechoic fundus surrounded by a hypoechoic rim, representing fluid within the space between the inverted fundus and the vaginal wall [10].

Three-dimensional ultrasound is an accessible tool in referral center ultrasound units. The technique of 3D power Doppler can clearly and quickly show the changes in the uterine artery course concerning the uterine body. It should be added to the available arsenal of sonographic signs for the diagnosis of uterine inversion in a non-gravid uterus.

Magnetic resonance imaging (MRI) is another imaging technique that can be utilized for diagnosing uterine inversion. MRI showing a U-shaped uterine cavity and inverted uterine fundus on a sagittal image and a ‘bulls-eye’ configuration on an axial image on T2-weighted MRI scans [9].

We suggest these sonographic findings as novel and pathognomonic signs of uterine inversion which may contribute to an accurate and quick diagnosis of this life-threatening gynecological complication.

Funding

The authors of this study declare no financial support was received for this study

Compliance with ethical standards

Ethical approval

This study report was approved by our institutional review board.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Conflict of interests

The authors of this study declare they have no conflict of interest.