case_images: PMC7719820_01
case_images: Timeline with relevant data from the episode of medical care.
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case_images: A timeline of the episode of medical care is shown in  Figure 1 .
case_images: Hematoxylin and eosin (H&E) staining and immunohistochemical analyses of the resected tumor. (A) The tumor cells arrange in a diffuse pattern(x4). (B) Epithelioid tumor cells are oval or polygonal, with clear or granular eosinophilic cytoplasm. Nucleoli are prominent in the vesicular nuclei. Increased mitotic activity and dysplasia are observed (x20). Tumor cells are positive for (C) HMB-45 (strong and diffuse), (D) Melan-A (patchy) and (E)
  TFE3 (modest and diffuse), and are negative for (F) SMA.
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case_images: Immunohistochemical stains ( Figure 2 ) showed tumor cells positive for Melan-A (patchy), HMB-45 (strong and diffuse), vimentin (patchy) and TFE3 (modest and diffuse), and negative for PAX-8, S-100, Syn, CK7, desmin, Myo-D1, SMA, and calponin.
case_images: RNA-based next-generation sequencing identified SFPQ-TFE3 fusion in tumor cells. (A) Visualization of the sequencing results through the Integrative Genomics Viewer (IGV). A SFPQ-TFE3 fusion was showed. (B) shows the location where the fusion took place. (C) shows the retained protein domains of the fusion protein.
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case_images: RNA-based next-generation sequencing identified SFPQ-TFE3 fusion in tumor cells ( Figure 3 ).
case_images: Response of apatinib for metastatic PEComa of the liver. (A) Multiple hepatic metastases revealed after surgery. (B) Tumor progression after everolimus treatment. (C) Response of hepatic metastases after apatinib treatment. (D) Tumor progression in April 2019.
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case_images: Unfortunately, the postoperative imaging showed progression of hepatic metastases ( Figure 4A ) and systemic treatment was needed. CT showed tumor progression on everolimus treatment ( Figure 4B ). Considering the gastrointestinal origin of the hepatic metastases, from August 13th she was treated with 500 mg qd apatinib, which is an anti-VEGFR2 TKI used in third-line treatment of gastric cancer (GC) in China. The tumor remained stable (but with necrosis in the center,  Figure 4C ) and the progression-free survival (PFS) lasted about 7 months. In March 2019, the hepatic metastases progressed ( Figure 4D ).