Cytological Features in Ascitic Fluid of Well-Differentiated Papillary Mesothelial Tumour.

Well‐differentiated papillary mesothelial tumour is a rare mesothelial proliferation that predominantly affects the peritoneum of female patients. It rarely presents with ascites and multiple miliary nodules resembling carcinomatosis or malignant mesothelioma. Pathologists must consider this entity when faced with a hypercellular mesothelial cell proliferation with few single cells, scarce cellular atypia, and no inflammation.