Characterization of neoplastic cells outlining the cystic space of invasive micropapillary carcinoma of the canine mammary gland

Abstract Background Invasive micropapillary carcinoma (IMPC) is a rare malignant breast tumor and variant form of invasive ductal that an aggressive neoplasm the human canine mammary gland. The importance microenvironment in cancer development has gradually been recognized, but little known about cell types outlining cystic space IMPC. This study aimed to characterize neoplastic cells Results Immunohistochemistry (IHC), immunofluorescence (IF), superresolution transmission electron microscopy (TEM) were used assess areas IMPCs. Cells expressing mesenchymal markers alpha-smooth muscle actin (?SMA), Vimentin, S100A4 outlined Furthermore, loss epithelial polarity IMPC was shown by localization MUC1 at stroma-facing surface. protein modulates lumen formation inhibits cell-stroma interaction. Immunohistochemical IF staining for myoepithelial marker p63 negative samples. associated with peculiar morphology, such as thin cytoplasmic extensions spaces, observed under TEM. These observations suggested characteristics myoepithelial-like cells. Conclusions gland characterized using IHC, presence ?SMA, stroma role tumor-associated fibroblasts microenvironment. reversal revealed limited basal may be important factor contributing invasiveness For first time, delimited had lost expression. findings enhance our understanding cellular tumors improve diagnosis treatment.