Received February 11, 2023
Accepted August 28, 2023

Herlyn-Werner-Wunderlich syndrome (SHWW) is characterized by the triad of uterus didelphys, obstructed hemivagina, and renal agenesis. The typical clinical presentation involves chronic pelvic pain, dysmenorrhea, and palpable abdominal mass, related to hematocolpos/hematometra. It is a rare disease with a challenging clinical and radiological diagnosis. Surgery is the definitive treatment. Complications such as endometriosis, infertility and chronic pelvic pain occur more frequently and severely when diagnosis and treatment are delayed. This is a case report of a twelve-year-old patient admitted to the Gynecology Department of the Federal University of Rio de Janeiro’s General Hospital (HUCFF/UFRJ), in March 2021, with progressive symptoms of dysmenorrhea and abdominal distention due to palpable abdominal mass. She had a previous history of congenital solitary kidney. Magnetic Resonance Imaging (MRI) showed a double uterus with hematometra and hematocolpos on the left side, pelvic endometriosis and left renal agenesis. Conservative clinical treatment with inhibition of the hypothalamic-pituitary-ovarian (H-P-O) axis was initiated while a definitive surgical approach was being defined. In June 2022, the patient underwent left hemi-hysterectomy and salpingectomy, achieving full remission of symptoms. Given the rarity of this syndrome and its potential complications, our report aims to familiarize professionals with it, mostly those who work with children and adolescents, so that more patients have access to early diagnosis and adequate treatment. Consequently, future fertility can be effectively preserved.