Deeply Infiltrating Endometriosis (DIE) No More: Dienogest as a Game Changer in Rectovaginal Endometriosis

Rectovaginal endometriosis remains a therapeutic enigma due to its relatively low incidence and widely differing opinions on the standard of its treatment. Dienogest is a relatively novel therapy for endometriosis and presents major therapeutic potential in the treatment of deeply infiltrating endometriosis. This is the case of a 36-year-old woman who presented to the Urogynaecology clinic with postcoital bleeding and a vaginal mass. She had a history of open myomectomy, removal of rectovaginal cysts, and endometriotic deposits from the Pouch of Douglas one year earlier, with no treatment from then until this presentation. Speculum examination revealed a 3 cm tongue-like firm mass arising from the posterior fornix with contact bleeding, and pelvic ultrasonography confirmed a 3.5 x 2.4 x 1.9 cm mass posterior to the cervix. The biopsy-proven deeply infiltrating endometriosis mass in the posterior fornix and pouch of Douglas responded well to oral Dienogest treatment. After three months of treatment, the patient was symptom-free, and the mass on rectovaginal examination had shrunk to 1 cm. The endometriosis deposits were clearly demonstrated to be in remission during rectovaginal examination and pelvic ultrasonography after nine months of therapy. The patient experienced minimal side effects on Dienogest, namely prolonged menstrual spotting, which also resolved after nine months of therapy. This is the first reported case of Dienogest successfully shrinking rectovaginal deeply infiltrating endometriosis from 3 cm to undetectable on ultrasound and vaginal examination. This case demonstrates the success of Dienogest as a therapeutic modality for rectovaginal endometriosis, highlighting its promising potential as a standard treatment approach in the long-term management of the relapsing, chronic, and debilitating nature of endometriosis.