case_images: PMC10477911_01
case_images: Histopathology features of primary tumors. (A) The boundary between tumor tissue and surrounding normal kidney tissue is not clear. (B) Epithelioid tumor cells were arranged in tight sheets. (C) Abundant epithelioid cells, a small amount of adipose tissue, and thick-walled blood vessels were seen in the tumor. (D-F) Epithelioid tumor cells are large and diverse, with some adipose vacuolar and acinar areas (indicated by the arrow in (D)), which are rich in eosinophilic or translucent cytoplasm. The nuclei were enlarged and deeply stained, partially vacuolated, and accompanied by obvious nucleoli (indicated by the arrow in (F)). The scattered megakaryocytes and occasionally pathological mitosis (indicated by the arrow in (E)) and necrosis could be observed (A, B H&E, x100; C-E H&E, x200; F, H&E, x400).
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case_images: f1
case_images: The epithelioid tumor cells were arranged in tight sheets ( Figures 1A-C ). They were large, round, or polygonal with some adipose vacuolar and acinar areas and had abundant cytoplasm, which was stained eosinophilic or transparent ( Figure 1D ). Necrotic and pathological mitosis were also observed ( Figure 1E ). Vacuolated and weird-type nuclei were also observed ( Figure 1F ).
case_images: Immunohistochemical staining of primary tumors. (A-C) HMB45, Melan-A, CK20 staining: diffuse and strong positive cytoplasm of tumor cells. (D) SMA staining: tumor cells were positive. (E) TFE3 staining: tumor cell nuclear was positive. (F) Ki-67 staining: The Ki-67 index hit 10% (A-D, F original magnification is x200; E original magnification is x100).
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case_images: f2
case_images: Immunohistochemical staining revealed that the tumor cells were diffusively positive for human melanoma black 45 (HMB45), melan antigen (Melan-A), cytokeratin (CK) 20, and transcription factor enhancer 3 (TFE3), and partly positive for smooth muscle actin (SMA) ( Figures 2A-E ), which indicated that the tumor originated from peripheral vascular epithelioid cells, ruling out RCC. The tumor cells were diffusely vimentin-positive, and a Ki-67 index ( Figure 2F ) of 10% suggested that the tumor was malignant.
case_images: Microscopic architectural features of a liver mass biopsy. (A-C) Proliferating fibrous tissue, eosinophilic cytoplasm, and significantly hyperchromatic and enlarged nuclei of epithelioid tumor cells could be observed (H&E, A x40; B x100; C x200). (D) Melan-A staining: diffuse and strong positive cytoplasm of tumor cells. (E) SMA staining: tumor cells were positive. (F) Ki-67 staining: the Ki-67 index hit 5% (D, F original magnification is x200; E original magnification is x100).
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case_images: PMC10477911_01_fonc-13-1207536-g003.jpg
case_images: f3
case_images: The morphological characteristics were similar to those of the primary lesion ( Figures 3A-C ). To confirm this hypothesis, we performed an immunohistochemical examination, which suggested diffuse positivity of liver tumor cells for Melan-A ( Figure 3D ) and SMA ( Figure 3E ). Its proliferation index hit 5% ( Figure 3F ).