STAT6 and leiomyosarcoma: Histology demonstrated a primary gastric low-grade ESS with a vascular pattern and low mitotic index, while immunohistochemistry showed diffuse CD10/ER/PR positivity and absence of c-KIT, DOG-1, desmin, S100, SOX10, and STAT6, excluding GIST, leiomyosarcoma, PEComa, solitary fibrous tumour, and schwannoma.