Immunohistochemical analysis of the canine inflammatory myofibroblastic tumour. Innmunohistochemical study

In their immunohistochemical study the authors reanalyse ten different canine soft tissue biopsy samples, which were diagnosed as chronic active inflammation with angiofibroblast tissue proliferation, based on light microscopic analysis of the hematoxylin and eosin stained slides. The immunohistochemical panel consisted of anti-vimentin, anti-a-SMA (anti-a-smooth muscle actin), anti-S-100 protein, anti-claudin-5, anti-lysozyme, and anti-PCNA (proliferating cell nuclear antigen). The neoplastic fusocellulare parenchymal cells of the biopsy samples showed vimentin-, a-SMA-positivity, and 5-100 protein-, claudin-5-, lysozyme-negativity. The inflammatory cells, such as histiocytes showed vimentin-, lysozyme-positivity, and a-SMA-, and 5-100 protein-, claudin-5-negativity. PCNA-labeling index of the samples were 30-35 %. The endothelial cells of the tumour-induced microvessels were positive for claudin-5, and vimentin, futhermore the smooth muscle cells of the neoangiogenetic vessels showed vimentin-, a-SMA positivity. Based on immunohistochemical analysis the definitive, revised diagnosis of the soft tissue samples was inflammatory myofibroblastic tumour. The authors suggest the immunohistochemical analysis of the canine soft tissue biopsy samples, in which mixed proliferation of the spindle shaped mesenchymal cells, and inflammatory cells (such as histiocytes, lymphocytes, plasma cells) can be seen with neoangiogenetic microvessels, and mitotic figures for the correct definitive diagnosis.