PGR and neoplasm: From the analysis of many demographic (sex and age), neuroradiological (tumor location and shape, brain–tumor interface), pathological (WHO grade, Ki67-MIB1, progesterone receptor expression), and surgical (entity of resection, number of reoperation) factors and time to recurrence and outcome, at initial diagnosis and at recurrence, revealed that the flat shape and values of Ki67 Li ≥ 4% were significantly associated with a higher risk of recurrence in multicentric–diffuse form.