IN 1925 Levin1 recorded a unique instance of universal psoriasis complicated by tumor-like formations. At that time he stated the belief that these lesions resembled those described by Unna2 (1890) as parakeratosis scutularis and by Weiss3 (1912) as parakeratosis ostracea. The outstanding clinical feature was the presence of verrucous excrescences, varying in size from that of a lentil to that of a quarter, some pale and others pink, and occurring chiefly on the lower limbs in irregular distribution. The pathologic features reported by Levin were those of typical psoriasis, accompanied with pronounced acanthosis of a degree sufficient to explain the warty clinical appearance. The tumor-like aspect was attributed by him to a combination of swelling of the fibrous tissue, intense acanthosis and cellular infiltration in the cutis. Arsenic was eliminated as a possible cause. In 1939 Levin presented this patient again.4 In the interim, since 1937,