Endometriosis-related ovarian neoplasms: pathogenesis and histopathologic features

A variety of neoplasms have been described to arise in association with ovarian endometriosis, characterized by younger age, earlier detection at lower stages, and better survival. The molecular pathogenesis of these tumours has become a focus of recent studies. Representative endometriosis-associated neoplasms include endometrioid carcinoma, clear cell carcinoma, seromucinous borderline tumour (endocervical-like mucinous borderline tumour; Müllerian mucinous borderline tumour), squamous cell carcinoma, Müllerian adenosarcoma, and endometrioid stromal sarcoma. Inflammation, oxidative stress by reactive oxygen species, and hyperestronism are implicated in the carcinogenesis of these tumours. A subset of endometriosis are monoclonal in nature and atypical endometriosis is considered to be a source of clear cell and endometrioid carcinomas through a variety of genetic alterations, including somatic mutations of PTEN, PIK3CA, or ARID1A. It is crucial to understand the clinicopathologic features and genetic background of endometriosis-related neoplasms in order to establish strategies for early detection and molecular-targeted therapy.