Fig. 4
From: Four cases of cell cannibalism in highly malignant feline and canine tumors
Case 4. Mesothelioma. Pleural cavity. Dog. a - Pleural effusion cytology smear showing frequent images of cellular internalization (arrows) (Giemsa). b – Large mediastinal mass can be seen together with various small nodules dispersed throughout the parietal pleura (arrows). c – Part of the tumor (upper left) was organized in variably sized lobules limited by trabeculae of fibrous tissue, formed by loosely arranged cells almost devoid of cytoplasm, with round nuclei. Extensive necrosis is visible, possibly due to chemotherapy. In other areas (lower right) the tissue is organized in single layers of epithelial cells covering papillary infoldings into cystic spaces filled with acidophilic content. d - IHC, anti-pancytokeratin antibody. Only the cells of the epithelial component are positive. Mayer’s hematoxylin counterstain