Solitary primary pulmonary synovial sarcoma: A case report

Figure 3 Hematoxylin and eosin staining. A: Hematoxylin and eosin (H&E) staining of tissue sections of posterior segment of the right lung upper lobe obtained from surgery (H&E 200×). The tumor was composed of spindle cells, which were arranged in dense cellular sheets or vague fascicles, with a herringbone architectural pattern; B-F Immunohistochemistry (IHC) revealed the tumor cells were diffusely positive for BCL-2 (B) and CD99 (C), and negative for CD34 (D), EMA (E) and TLE1 (F). The blood vessels inside the tumor showed positive staining for CD99 (C) (IHC 200×); G: Fluorescence in situ hybridization analyses: Red and green signals show break-apart regions (white arrows), representing the splitting of SS18 (synovial sarcoma translocation, SYT).