Broad spectrum of leukoderma acquisitum centrifugum.

A series of diverse neuroectodermally derived tumors associated with halos of leukoderma is presented. Clinically these lesions have in common a centrally placed, usually pigmented tumor encircled by a zone of hypopigmentation. The histological findings include (1) reduction or absence of epidermal melanin, but persistence of amelanotic melanocytes in the leukodermic halo; (2) a variety of tumors including nevus-cell nevus, neuroid nevus, blue nevus, neurofibroma, and malignant melanoma; (3) variable numbers of "small dark cells" whose nature is unclear, and which probably represent in part small nevus cells and in part lymphoid cells; and (4) damage to some tumor cells which presumably could be the cause of their destruction. Also presented are histochemical demonstrations of tyrosinase activity and immunohistochemical studies for presence of gamma-globulin in the tumors. Using the fluorescent antibody technique it was not possible to show gamma-globulins in patients' sera directed against their tumors. The relationship of developing hypopigmentation to the spontaneous regression of cutaneous neuroectodermally derived tumors is discussed.