[Eruptive keratoacanthoma].

A 74 year old woman showed typical symptoms of eruptive keratoacanthomas since three years: exanthematic sudden appearance of numberless papules, few millimeters in diameter with central keratinization, masked facies, ectropion of the eyelids and pruritus. Histology revealed the characteristic architecture of keratoacanthoma. Proliferation kinetics were characterized by increase of cell division within the basal cell layer, prolongation of time for DNA-synthesis (15,7 h) and moderate decrease of generation time. The reactive inflammatory dermal infiltrate mainly consists of lymphocytes. Ultrastructural features comprise occurrence of intracellular desmosomes and elastic and collagen fibers between the tumor cells. Therapeutically a good response was observed to aromatic retinoid Ro 10-9359.