The classical histological description is of a tumour with bland spindle cells thatare weakly eosinophilic, set in loose stroma with multiple vascular channels,oedematous foci and scattered inflammatory cells including lymphocytes and macrophages.1, 2,4 The tumours also have a very characteristic immunohistochemical profile andare positive for oestrogen and progesterone, CD34, vimentin and desmin,1, 2 but do not express smooth muscle actin, which distinguishes them from leiomyomas.5 The gene discussed is DES; the disease is leiomyoma.