WT1 and neoplasm: Microscopically, the tumor is comprised mostly of variably sized papillary formations with fibrovascular cores and covered by cuboidal, columnar, or flattened mesothelial cells with large vesicular nuclei and glassy eosinophilic cytoplasm [9,10], whereas the present case consisted of mucinous epithelial lining and was negative for WT-1, a well-known positive marker of mesothelial cells.