case_images: PMC9948607_01
case_images: A 16x10mm atrophic erythematous plaque on her right chest.
case_images: fonc-13-1100398-g001.jpg
case_images: PMC9948607_01_fonc-13-1100398-g001.jpg
case_images: f1
case_images: Physical examination showed a 16x10 mm asymptomatic, smooth, atrophic plaque ( Figure 1 ).
case_images: (A) Spindle cells infiltrate into the deep dermis and subcutaneous tissue, Hematoxylin-eosin (HE) x40; (B) Dense proliferation of spindle cells in a storiform pattern, HE x100; (C) Spindle cells are strongly positive for CD34, x40.
case_images: fonc-13-1100398-g002.jpg
case_images: PMC9948607_01_fonc-13-1100398-g002.jpg
case_images: f2
case_images: Histopathologic examination revealed a monomorphic fibrohistiocytic spindle cell tumor arranged in a storiform pattern infiltrating the deep dermis and subcutaneous tissue forming honeycomb-like pattern ( Figures 2A, B ). Immunohistochemical analysis showed that cells were prominently positive for CD34 ( Figure 2C ) and negative for protein S-100.
case_images: PMC9948607_02
case_images: A round erythematous-to-bluish atrophic plaque.
case_images: fonc-13-1100398-g003.jpg
case_images: PMC9948607_02_fonc-13-1100398-g003.jpg
case_images: f3
case_images: Physical examination showed a 30x20 mm round erythematous-to-bluish plaque with atrophy ( Figure 3 ).
case_images: Histopathological examination. (A) Fascicles of spindle cells with reduced dermal thickness by about half on low-power view, HE x40; (B) Monomorphic spindle cells with bland cytoplasm and scattered dendritic cells containing abundant melanin, HE x200; (C) Immunohistochemistry showed CD34+ cells infiltrating into subcutis and forming honeycomb-like pattern, x40; (D) Immunohistochemistry showed spindle cells were negative for S-100, in contrast, melanin-bearing dendritic cells were positive for S-100, x100.
case_images: fonc-13-1100398-g004.jpg
case_images: PMC9948607_02_fonc-13-1100398-g004.jpg
case_images: f4
case_images: Cells containing brown pigment were scattered in the dermis ( Figures 4A, B ). Immunohistochemical staining showed that the spindle cells were diffusely positive for CD34 but negative for S-100 while melanin-laden dendritic cells were positive for S-100 ( Figures 4C, D ).