case_images: PMC10521201_01
case_images: A) Neoplasm infiltrating dermis in a diffuse manner. At low magnification, a blend of different patterns can be seen. (H&E; x10). B) Upper part of the tumor. This part is cellular, composed of spindle and ovoid cells. Overlying epidermis shows hyperkeratotic and hyperplastic changes. (H&E; x40)
case_images: TurkPatolojiDerg-39-11936-g001.jpg
case_images: PMC10521201_01_TurkPatolojiDerg-39-11936-g001.jpg
case_images: F99032951
case_images: Microscopic sections revealed a neoplasm infiltrating the dermis and overlying a hyperkeratotic and hyperplastic epidermis (Figure 1). The most superficial portion of the tumor was relatively cellular with a few multinucleated giant cells (Figure 1).
case_images: A) Middle part of the tumor with a striking Verocaybody like appearance. Acellular hyaline zones are lined with palisading elongated cells. This is a typical feature of schwannoma. (H&E; x100). B) Deeper part of the tumor. Fascicles of spindle cells, scattered inflammatory cells, and foamy macrophages are seen. These findings are typical for fibrohistiocytic tumors. (H&E; x100). C) Cytoplasmic Factor XIIIa expression of the tumor. Both Verocay body-like (left half of the figure) and fibrohistiocytic (right half of the figure) parts of the tumor are positive for the antibody. (IHC; x100).
case_images: TurkPatolojiDerg-39-11936-g002.jpg
case_images: PMC10521201_01_TurkPatolojiDerg-39-11936-g002.jpg
case_images: F11068521
case_images: The deep portion of the tumor showed a storiform pattern with short fascicles, collagenous stroma, fibrohistiocytic proliferation, and small clusters of foamy macrophages, giving this part of the tumor a more conventional dermatofibroma appearance (Figure 2). In between, there was a zone of palisading cells, indistinguishable from the Verocay bodies of schwannoma (Figure 2). In all compartments including Verocay body-like areas, the tumor cells showed immunoreactivity for Factor XIIIa while they were negative for CD34 and S-100 antibodies, and the latter two excluded DFSP and schwannoma, respectively (Figure 2).