Case presentation

A 16-year-old female presented with a 1.5-year history of progressively worsening dysmenorrhea. Initially, her menstrual cycles were regular; however, they gradually became irregular, occurring approximately every 3 months.

The patient reported intermittent left lower abdominal pain, particularly during menstruation. There were no associated symptoms such as nausea, vomiting, dysuria, abnormal vaginal discharge, or palpable abdominal mass. She attained menarche at the age of 14 years.

The patient underwent transabdominal ultrasonography as the initial imaging modality. Abdominal ultrasound demonstrated a normal right kidney, while no normal renal structure was identified in the left renal fossa, consistent with left renal agenesis. Pelvic ultrasound revealed the presence of 2 separate uterine structures, suggestive of uterus didelphys. In addition, a cystic lesion was identified in the left adnexal region, characterized by homogeneous low-level internal echoes producing a “ground-glass” appearance, with associated peripheral punctate echogenic foci, consistent with an endometriotic cyst (endometrioma). The lesion showed no significant internal vascularity on Doppler evaluation. These sonographic findings raised suspicion for a complex Müllerian duct anomaly with associated adnexal pathology (Fig. 1).

Fig. 1: Transabdominal ultrasonography findings. (A) Normal right kidney. (B) Absence of the left kidney, consistent with renal agenesis. (C) Two separate uterine structures, suggestive of uterus didelphys. (D) Left adnexal cystic lesion demonstrating homogeneous low-level internal echoes with a ground glass appearance and peripheral echogenic foci, consistent with an endometrioma.

Pelvic magnetic resonance imaging (MRI) was subsequently performed to further characterize the Müllerian anomaly and to confirm the presence of associated complications. Sagital T2-weighted images, sagittal and axial T2-weighted fat-suppressed image demonstrated 2 completely separate uterine bodies, consistent with uterus didelphys. The right-sided uterus and cervix appeared normally formed and were connected to a patent hemivagina without evidence of obstruction. In contrast, the left uterine structure showed absence of a visible cervix, consistent with cervical atresia, accompanied by marked distention of the endometrial cavity without communication to the vagina, indicating complete obstruction of the left hemivagina. These findings are in keeping with obstructed hemivagina with ipsilateral renal anomaly, consistent with Herlyn-Werner-Wunderlich syndrome, specifically the cervicovaginal atresia subtype (Fig. 2).

Fig. 2: Pelvic MRI demonstrating features of Herlyn-Werner-Wunderlich syndrome with associated complications. (A) Sagittal T2-weighted image, (B) Sagittal T2-weighted fat-suppressed image, (C) Axial T2-weighted fat-suppressed image. All images demonstrate 2 separate uterine bodies consistent with uterus didelphys. The posterior structure represents the right uterus with a normal cervix and patent hemivagina (marked with a green arrow), without evidence of obstruction. The anterior enlarged structure represents the left uterus (marked with a red arrow), demonstrating absence of a visible cervix (cervical atresia), accompanied by marked distention of the endometrial cavity and no communication with the vaginal canal, consistent with obstructed hemivagina.

Coronal abdominal T2-weighted images demonstrated a normal right kidney, while the left kidney was not visualized, confirming left renal agenesis. The right adnexa appeared normal, with preservation of the right ovary (Fig. 3).

Fig. 3: Abdominal MRI demonstrating renal anomaly associated with OHVIRA syndrome. (A) Coronal T2-weighted STIR image demonstrating a normal right kidney (marked with a red circle), with absence of the left kidney, consistent with left renal agenesis. (B) Coronal T2-weighted image showing the normal right kidney, absence of the left kidney, and visualization of the normal right uterus (marked with a red arrow) and ovary (marked with a blue arrow).

Further evaluation with T1-weighted and T2-weighted pelvic sequences demonstrated marked distention of the left endometrial cavity with high signal intensity on T1-weighted and T1 fat-suppressed images, consistent with hematometra. Additionally, a cystic lesion was identified in the left adnexal region involving the left ovary, demonstrating high signal intensity on T1-weighted images with corresponding hypointensity on T2-weighted images, representing the shading sign characteristic of an ovarian endometrioma (Fig. 4).

Fig. 4: MRI features of hematometra and left ovarian endometrioma. (A) Coronal T1-weighted image, (B–C) Axial T1-weighted fat-suppressed images, and (D–E) Sagittal T2-weighted fat-suppressed and T2-weighted images. The left distended endometrial cavity (marked with a blue star) demonstrates high signal intensity on T1-weighted and T1 fat-suppressed images, consistent with hematometra. A cystic lesion in the left adnexal region (marked with a red star) demonstrates high signal intensity on T1-weighted images with corresponding low signal intensity on T2-weighted sequences, representing the characteristic shading sign, which reflects chronic blood products containing deoxyhemoglobin and methemoglobin, a hallmark feature of an ovarian endometrioma. The right uterine unit (marked with a green arrow) appears normal without evidence of obstruction.

To further evaluate the associated urinary tract anomaly, computed tomography (CT) urography in the excretory phase was performed. The examination demonstrated complete absence of the left kidney and left ureter, confirming left renal agenesis. The right kidney appeared normal in size, morphology, and contrast enhancement, with preserved excretory function and a normally opacified right ureter. These findings corroborated the MRI findings and further supported the diagnosis of Herlyn-Werner-Wunderlich syndrome by confirming the associated ipsilateral renal anomaly (Fig. 5).

Fig. 5: CT urography demonstrating the associated urinary tract anomaly. (A) Coronal contrast-enhanced CT urography (excretory phase) demonstrates complete absence of the left kidney and left ureter, consistent with left renal agenesis. The right kidney (marked with a green arrow) is normal in size and morphology, with homogeneous contrast enhancement and preserved excretory function, evidenced by opacification of the right renal collecting system and ureter. (B) Three-dimensional volume-rendered CT urography reconstruction confirms complete absence of the left kidney and ureter. The right kidney (marked with a green arrow) and ureter are normally developed, with preserved continuity of the right urinary tract extending to the urinary bladder.

Based on the examination, her final diagnosis is a rare case of Herlyn-Werner-Wunderlich syndrome classification 1.2, also referred as cervicovaginal atresia without communicating uteri, characterized by characterized by uterus didelphys, obstructed hemivagina, ipsilateral renal agenesis, and associated endometrioma. The doctors had recommended surgery but she chose conservative treatment over surgery. Therefore, dienogest was administered for sympomatic treatment, particularly pain. Her symptoms improve after having dienogest. The summary findings in the present case was summarized in Figure 6.

Fig. 6: Schematic illustration of Herlyn-Werner-Wunderlich syndrome (classification 1.2) in the present case. Schematic illustration of Herlyn-Werner-Wunderlich syndrome demonstrating the classification 1.2 variant (cervicovaginal atresia without communicating uteri), corresponding to the present case. The diagram shows uterus didelphys with 2 completely separated uterine horns. The right uterine unit (the normal side) is connected to a patent cervix and vagina, allowing for normal menstrual outflow. In contrast, the left uterine unit demonstrates cervicovaginal atresia, resulting in complete outflow obstruction and hematometra. Ipsilateral (left-sided) renal agenesis is also depicted. Additionally, the left ovary demonstrates an endometrioma, likely secondary to chronic retrograde menstruation caused by longstanding obstruction. This schematic highlights the anatomical basis of the patient’s symptoms and the development of associated complications.