Pseudoxanthomatous salpingitis: Report of two cases with distinctive microscopical findings

Background and aim: We describe two cases of pseudoxanthomatous salpingitis (PXS), an uncommon entity, often unknown for clinicians and pathologists. We review the literature on this topic and perform immunohistochemistry in order to study its pathogenesis. Methods: Both cases are studied by histochemical and immnunohistochemical methods with a wide panel of antibodies. Results: One case showed bilateral PXS, ovarian endometriosis and an adenomatoid tumor in the right tube. The second case showed a unilateral focus of tubal endometriosis. The first case displayed pigmented histiocytes, positive with periodic acid-Schiff (PAS), PAS with diastase digestion and focally with Fontana-Masson stains. Abundant hemosiderin granules were present in stromal subepithelial cells but no in histiocytes. In the second case Fontana-Masson and Ziehl-Neelsen methods stained diffusely the histiocytes. Perls stain was positive in some stromal cells and in numerous granular macrophages. The lymphocytic infiltrates presented mainly T cells with different proportions of CD4 and CD8 lymphocytes in each case. The tubal stroma was positive for CD10 in both cases. Conclusions: PXS is a rare condition usually associated with ovarian endometriosis. The physiopathologic way of pseudoxanthomatous histiocytes to accumulate inside the plicae of the tubes is not clear and can be diverse in different cases.