“…Among the most frequent histological variants of mesothelioma is epithelioid (50-70%) as a set of buds with delicate gripping growths covered with prismatic, cubic or polygonal cells with pale vacuolated cytoplasm and with evidence of cellular polymorphism, hyperchromatosis of the nuclei, the www.intechopen.com presence of pathological mitoses and giant cells, as if spun from each other, that is, in our opinion, the pathognomonic morphological sign of mesothelioma, and for which can not be wrong [115]. The other type is sarcomatoid which is much more serious than the epithelioid, and it affects the secondary tissues including the bone, muscles, cartilage or fat [94]. This type of cancer cell is a much more rare type that occurs in 7-20% of the cases.…”