(74) Labial Adhesion Mimicking a Persistent Urogenital Sinus in a Reproductive-Aged Woman: a Case Report

Background: Labial adhesion is a condition generally associated with hypoestrogenic status of prepubertal girls but can also occur during reproductive years related to vulvar trauma (mutilation, delivery, sexual abuse) or inflammatory diseases (herpes, lichen, lupus). In severe and long-standing cases, it can mimic congenital anomalies, such as persistent urogenital sinus (PUS), when is difficult to distinguish the characteristic midline raphe of a fusion. The purpose of this case it to portray the difficulties of the differential diagnosis of persistent labial adhesions and congenital malformations.

Case: A 16-year-old patient was referred to pediatric and adolescent gynecology due to suspected PUS but was lost to follow up. She came back at the age of 22 when she became sexually active but could not attain vaginal penetration. There was no history of urinary tract infections, or inflammatory disease. She had regular menstrual periods and mild dysmenorrhea. Upon careful confidential interrogation she revealed a history of sexual abuse from age 4 to 10. Physical exam revealed complete adhesion (dense and fibrous) of the labia majora, perineum measuring 10 cm in length, with an opening of 1 cm without clitoromegaly. The urethra was not visible (Figure 1). A trans perineal ultrasound showed independence between the urethra and vagina. Vaginoscopy was performed and revealed a normal vagina, fornix and cervix. The urethra was identified, and cystoscopy confirmed normal bladder anatomy. A sharp dissection using a cold scalpel under anesthesia was carried out, successfully restoring the anatomical structures (Figure 2).

Comments: Persistent urogenital sinus is a rare congenital condition where there is a convergence between the genital and urinary ducts. Clinical presentation depends on the site of convergence and the size of the sinus ostium. In cases where patients are asymptomatic or Stage I of Powell's classification (labial fusion), acquired labia adhesion should be considered as a differential diagnosis.
Labial adhesions in pre pubertal girls can be treated with localized massages and almost all cases resolve with puberty. When evaluating post pubertal patients with labia adhesion, it is essential to rule out congenital malformations and inquire about their biopsychosocial history and conduct a comprehensive interview covering all aspects, with particular attention to factors such as abuse and trauma during the medical history.