[Malignant hair follicle tumor]

A malignant hair follicle tumor was investigated by light and electron microscopy. The tumor was excised from the scalp of a 46-year-old woman and had recurred rapidly. Half a year after radical excision a metastasis in a cervical lymphnode occurred. The very inhomogeneous pattern of partly differentiated tricholemmal cysts and partly undifferentiated infiltrating areas changed to an aggressively growing, scanty differentiated tumor when it recurred and metastasized. Both findings stress the character of malignancy. Prognostic aspects and histogenesis are compared with similar cases in literature.