[MESOTHELIOMA, EPITHELIOD]. Malignant mesothelioma is the most common primary malignancy of the pleura. However, metastatic cancers to pleura are much more common than mesothelioma and are mainly metastatic lung cancers. Several histologic forms are recognized including epithelial/epitheliod, spindle cell/sarcomatoid, biphasic, desmoplastic, deciduoid, and lymphohistiocytoid. This epithelial/epitheliod mesothelioma of pleura (arrowhead) shows proliferation of malignant mesothelial cells in interanastomosing cords (arrow) and invading down into the pleural tissue.