Four cases of cell cannibalism in highly malignant feline and canine tumors

• DOI: 10.1186/s13000-015-0429-3
• Publication Date: 2015-11-02T16:31:48Z
• Authors: Fernando Costa Fe...; Maria João Soares; Sandra Carvalho; Liliana Borralho; Gonçalo Vicente; Sandra Branco; Jorge Correia; Maria Conceição P...
• Keywords: Male; Mesothelioma; Histology; Lung Neoplasms; Skin Neoplasms; Biopsy; Pleural Neoplasms; Case Report; Mammary Neoplasms, Animal; Cat Diseases; Cell cannibalism; Pathology and Forensic Medicine; 03 medical and health sciences; Dogs; 0302 clinical medicine; Biomarkers, Tumor; Animals; Dog Diseases; Cytokeratin; Neoplasia; Carcinoma; E-cadherin; Cadherins; Immunohistochemistry; 3. Good health; Cytophagocytosis; Carcinoma, Squamous Cell; Cats; Keratins; Female

Four cases of tumors in which cell internalization was frequently visualized are reported: one feline mammary carcinoma, one feline cutaneous squamous cell carcinoma, one canine pulmonary squamous cell carcinoma and one canine pleural mesothelioma. Cell internalization was observed by cytology in two of these cases (the feline mammary tumour and the pleural effusion in the canine mesothelioma) and by histopathology in all but the canine mesothelioma. Immunohistochemical staining for pancytokeratin was positive for both internalized and host cells, while E-cadherin expression was frequently absent, although internalized cells occasionally stained positive. This cell-to-cell interaction seems to be associated with tumors displaying a strong epithelial-mesenchymal transitional phenotype, in which cancer cells become engulfed by other cancer cells. Such event could be regarded as an important hallmark of very high malignancy.