ACTA1 and neoplasm: With our objective in mind, we modified and simplified the classification and, depending on the predominant type/s of stromal cell/s in the tumour, grouped the cases as follows: (a) a predominance of CD34+SCs (26.01% of cases), (b) a predominance of αSMA+ stromal cells (30.9% of cases) and (c) a balanced presence of both markers (42.85% of cases).