Idiopathic solitary neuroma of skin with unusual histologic changes

We report herein a case of idiopathic solitary neuroma with vascular proliferation and neurofibroma-like features. Clinically, the skin lesion was a 0.7 cm nodule without tenderness on the forearm. Histologically, there was vascular proliferation in the upper dermis, some neural structures among the proliferative vasculature in the mid dermis and large bundles of neural structures extending in various directions in the mid and deep dermis (resembling neurofibroma). Special stains, such as Masson's trichrome and Luxol fast blue, and immunohistochemical studies, including S-100 protein, neuron-specific enolase (NSE), vimentin, desmin, factor-VIII related antigen and epithelial membrane antigen (EMA), were added for this very rare case.