SMN1 and neoplasm: In some nodules, the collagenous stroma was densely hyalinized.[7] Frequent ulceration, mucosal invasion, and vascular invasion had no adverse significance in these tumors.[6] Immunohistochemically, the tumor cells were diffusely immunoreactive for SMA and vimentin, and focally immunoreactive for H-caldesmon, desmin, and CD10.