Atypical fibroxanthoma of the skin with metastasis.

Cutaneous atypical fibroxanthoma (AFX) occurs in elderly persons as a small nodule or ulcernodule in actinically damaged skin of the head and neck area. The vast majority of AFX behave in a benign manner, and metastasis is rare. Eight examples of metastasizing AFX are reported. Factors that portend aggressive behavior and metastasis are vascular invasion, recurrence, deep tissue invasion, tumor necrosis and, possibly, defective or depressed host resistance. The metastasizing primary AFX were located on the head, and the metastasis involved the structures in the region of the parotid gland.