Histological analysis of the surgical specimens confirmed the presence of a malignant biphasic tumor with a mixed spindle cell and epithelioid pattern infiltrating the peritoneum, with brisk mitotic activity (Figure 7) deviating from previous results due to the recurrent positivity of mesothelial markers, including calretinin, WT-1, and D2-40/podoplanin (Figure 8). This evidence concerns the gene PDPN and neoplasm.