These are very rare on the face or trunk, but almost any other site, including buttocks, genitalia, and scalp, may be involved. Most of the cases occur on the extremities, particularly the upper extremity. Recurrences are very common. Metastasizes to lymph nodes or by blood stream. May metastasize to skin or produce satellites.
Cutaneous tumors are prone to ulcerate.
The differential diagnosis includes many cytologically atypical and cytologically malignant tumors of skin. In addition, the d ifferential diagnosis includes necrobiotic palisading granulomatous diseases. Small round foci of extension resembling ordinary granulomas. Central necrosis or necrobiosis is very characteristic . The central material may be composed of necrotic tumor or altered connective tissue.