Figure 2 Histological characteristics of pancreatic SFT. (A) Under low magnification, it can be observed that the tumor tissue surrounds the normal pancreatic tissue (Case 1) (Hematoxylin – Eosin stain, 40×). (B) The morphological appearance of tumor tissues was diverse, exhibiting either a fascicular growth pattern (Case 1) (Hematoxylin – Eosin stain, 200×), or (C) The so-called “patternless growth pattern” (Case 2) (Hematoxylin – Eosin stain, 200×). (D) Branching and antler-like small blood vessels were visible in the tumor stroma (Hematoxylin – Eosin stain, 200×). (E) Under high magnification, Case 1 histology revealed tumor cells with spindle-shaped, oval nuclei and no atypia or mitoses (Hematoxylin – Eosin stain, 400×). (F) In Case 2, there was a significant increased deposit of collagen fibers between the tumor cells, and the tumor cells themselves exhibited no atypia (Hematoxylin – Eosin stain, 400×). (G) The tumor cell nuclei strongly expressed STAT6 (EliVision method, 200×). (H) The tumor cell cytoplasm expressed CD34 (EliVision method, 200×). SFT – solitary fibrous tumor.