Modification of endometrioma size during hormone therapy containing dienogest

The aim of the present study was to evaluate whether hormone therapy containing dienogest is effective in reducing endometrioma size. A retrospective observational study was conducted on 116 women with endometrioma which was evaluated after 6 and 12 months of either no treatment (n = 46), or hormonal therapy containing dienogest (n = 70), without (DNG; n = 34) or with ethinylestradiol (DNG/EE; n = 36). Median (interquartile range) cyst diameter (23.0 mm (21.0 mm)) and volume (9941.2 mm³ (14240.1 mm³)) of untreated were similar to cyst diameter (25.0 mm (14.5 mm) and volume (7587.7 mm³ (13806.2 mm³)) of treated women. After 12 months, endometrioma volume did not vary in untreated women (-34.0 mm³ (55595.0 mm³); -0.77% (93.9%)) while it significantly decreased (-5400 mm³ (15378.7 mm³); -100.0% (27.7%); p<.0001) during hormone therapy. Volume decrease was linearly related to endometrioma volume ([Formula: see text] R² = 0.899, p<.0001). The effect tended to be greater during DNG alone than DNG/EE (-100.0% (0.0%) vs. -87.9% (47.7%); p<.0004). Cyst disappearance was observed in 4.4% of untreated cases and in 57.1% of cases on hormone therapy (p<.0001) (38.9% with DNG/EE and 76.5% with DNG; p<.03). The early diagnosis and treatment of endometrioma with dienogest-based hormone therapy may be effective in controlling cyst growth and in reducing the need for surgery.