OPRM1 and fibroma: The OPRM1(+) morphine receptor mutation was more frequently encountered in patients with biopsy uterine curettage (60%) with benign results in anatomopathology, uterine myomectomy of at least 5 cm fibromas with benign results in anatomopathology (50%), Madden mastectomy (50%), interventional hysteroscopy (33.3%) with extraction of benign tumors such as polyps or endometrial hyperplasia, caesarean section-associated surgeries (20.7%), and ovarian cystectomy (20%) (<i>p</i> = 0.048) that had a final benign anatomopathology result.