MSH: A benign compound nevus occurring most often in children before puberty, composed of spindle and epithelioid cells located mainly in the dermis, sometimes in association with large atypical cells and multinucleate cells, and having a close histopathological resemblance to malignant melanoma. The tumor presents as a smooth to slightly scaly, round to oval, raised, firm papule or nodule, ranging in color from pink-tan to purplish red, often with surface telangiectasia. (Dorland, 27th ed),NCI: A benign, acquired or congenital, usually single skin lesion. It can occur on any area of the body, but most commonly occurs on the face of children and the thighs of young females. It is characterized by a proliferation of large spindle, oval, or large epithelioid melanocytes in the dermal-epidermal junction. The melanocytic proliferation subsequently extends into the dermis.