Are oestrogens and genetic predisposition etiologic factors in the development of clear cell carcinoma of the peritoneum?

A literature search was carried out for clinical observations that could explain the possible aetiology of primary peritoneal clear cell carcinoma (CCC) including diagnostic dilemmas, various theories of origin, oestrogen dependence and genetic association. It was found to be an extremely rare tumour (CCC) arising in the peritoneum and is often misdiagnosed as mesothelioma or serous carcinoma or metastatic adenocarcinoma due to overlapping morphological features. The awareness of such dilemmas is important even before making a diagnosis. Clinicopathological features and immunohistochemical studies like WT1, CK20 and calretinin are usually helpful in differentiating CCC from serous carcinoma, metastatic carcinoma from bowel and mesothelioma. (CK7 is common to all epithelial tumours, CEA can be expressed in clear cell carcinoma, WT1 is normally expressed in serous carcinoma, calretinin is expressed in mesothelioma and CK20 in colon carcinoma). The distinction between the above tumours is important as correct diagnosis is required in initiating appropriate treatment. Less than ten cases have been reported in the English language medical literature. Mullerian metaplasia and malignant transformation in endometriosis are two theories proposed for its existence. Peritoneal CCC can be oestrogen dependent in view of association with oestrogen dependent conditions which include endometriosis, adenomyosis and endometrial carcinoma. A genetic ascertain is difficult to be associated and needs further evaluation in a research setting in the familial cancer genetic clinics.