**8. Adenomyosis malignant transformation**

As with other pathologies of endometriosis, adenomyosis may goes malignant transformation. It is not clear whether some malignancies being as such or progress from benign disease to malignant. The neoplasia arises coincidentally in continuity with endometriotic implants.

Although adenomyosis is usually benign, it might also be a precursor of malignant disease. As the incidence of adenomyosis malignant transformation is low, and its clinical manifestation is nonspecific, it may only be confirmed by postoperative pathological examination. Malignant neoplasia occurs rarely in the glands and/ or stroma; these tumors may be in the form of adenocarcinomas, sarcomas, or carcinosarcomas. Further investigations with large samples may provide additional data of the prognosis of adenomyosis malignant transformation [26]. Some of the risk factors of malignant adenomyosis include age between 40 and 50 years, early menarche, short menstrual cycle, first delivery at young age, fertility, curettage during early trimester of pregnancy, obesity, and history of tamoxifen intake. The expression of both PR and ER was positive in patients with endometrial carcinoma combined with adenomyosis or endometrial carcinoma combined with uterine fibroids, and the expression of p53 and Ki67 was positive in eutopic malignant endometrium and negative in normal ectopic endometrium, which may provide additional pathological data on adenomyosis malignant transformation [26, 27].
