Conclusion

Herlyn-Werner-Wunderlich syndrome should be considered in adolescent females presenting with progressive dysmenorrhea, particularly when symptoms are persistent or atypical. This case highlights a type 1.2 obstructive variant with cervicovaginal atresia, in which delayed diagnosis led to secondary complications, including hematometra and ovarian endometrioma. Pelvic ultrasonography serves as an effective first-line imaging modality, whereas MRI is the gold standard for definitive diagnosis, accurate classification, and assessment of associated complications. CT urography complements MRI by providing detailed evaluation of concomitant urinary tract anomalies. Early recognition of this condition is crucial to prevent complications related to chronic outflow obstruction and retrograde menstruation. Although conservative management with Dienogest provided symptomatic relief in this patient, it does not address the underlying structural anomaly. Definitive surgical correction is therefore required to relieve obstruction, prevent recurrence, and preserve future reproductive function.