[Aggressive angiomyxoma of the female pelvis and perineum, M-8841/1]

Aggressive angiomyxoma of pelvis and perineum was identified in two women (of 31 and 53). Its site was in the right fossa ischiorectalis and vulva. There was not observed any relaps in 60 and/or 9 months after surgery. Amorphous tumour mass was soft with finger-like projections. Spindle and starshaped tumour cells were spread in a loose edematous myxoid vascularized stroma; they had a benign character lacking of mitoses and nuclear atypia. Myxoid stroma could be stained rather faintly with Alcian blue at pH 1. Dilated capillaries, veins and arterioles were a substantial component of the tumour. Nerve and muscle fibres and their fragments were included here and there in the tumour. Tumour cells had a fibroblast ultrastructure which was supported by immunohistology. Discussion comprised differential diagnosis of myxoma, myxoid liposarcoma and myxoid type malignant fibrous histiocytoma among others.