Differential diagnosis of peritoneal lesions of müllerian type and similar epithelial tumors of the peritoneum.

The female peritoneum is the site of various tumor-like and tumorous lesions that resemble derivatives of the primary müllerian system. Those lesions can therefore be summarized under the term secondary müllerian system. These lesions can cause problems in macroscopic and microscopic examination if clinicians or pathologists are not acquainted with them. The relationship between the derivatives of the embryonal müllerian duct and the secondary müllerian system is underscored by the expression of many different antigens, as revealed by immunohistology.