Ding D, et al. - Among 30 adolescent patients, aged 15 to 19 years, and 32 adult patients, aged 35 to 39 years, experts aspired to explore if ovarian endometrioma (OE) is progressive or not. According to results, OE lesions are markedly different from adolescent and adult patients, with the latter displaying more extensive and thorough progression and more extensive fibrosis, indicating that lesions in adults progressed to a more advanced stage. The extent of lesional fibrosis is positively correlated with adult lesions and higher staining levels of α-smooth muscle actin and adrenergic receptor β2, whereas the lesion size and the E-cadherin staining are negatively related. The results offer a more definitive piece of evidence indicating that OE is a progressive disease, as lesions in the adult have longer time for progression. Additionally, the pace of progression depends on lesional age and, if any, the severity of dysmenorrhea associated with endometriosis.