Histology and ultrastructure of human endometriotic tissues treated with dydrogesterone (Duphaston).

The histological and ultrastructural changes of ectopic endometrium were studied during treatment with dydrogesterone (Duphaston) in eighteen infertile patients with laparoscopically confirmed endometriosis. Three types of response to therapy, i.e. no response, moderate and good, are detailed. First, focal secretory transformation of the endometriotic epithelium with decidualization of the ectopic stroma was seen in four patients (no response to therapy). In all other patients, the endometriotic implants were undifferentiated (moderate response to therapy) or revealed morphologic features of involution (good response to therapy). Proliferation of endometriotic cells was not seen during treatment with Duphaston, while total eradication of microscopic implants was never observed. Endometriotic implants with good response to Duphaston therapy demonstrated an enhanced autophagic activity within many epithelial cells. Only two patients conceived during a one-year post-treatment follow-up. Both patients demonstrated a good response to therapy.