Lymphomatoid papulosis: a study of 18 cases*

Abstract

Lymphomatoid papulosis (LyP) is a cutaneous eruption that is clinically benign but histologically malignant. To date, more than 300 cases have been published. About 10-20% of the patients develop a lymphoma. The purpose of this study was to make a clinicopathological study of 18 patients diagnosed with LyP in our hospital from 1973 to 1990, to characterize cellular infiltrates in the lesions, to find clonal populations of T-cells and to look for predictive factors of malignant lymphoma in LyP patients. Mean age was 48.7 years. The most frequent clinical lesions were papules (88.8%) followed by plaques (38.8%). The localizations were on extremities (loo%), trunk (88%), face (22%), palms or soles (ll%), perigenital(ll%) and scalp (5%). Two patients have been free of disease for more than 5 years. IgA levels are increased in LyP patients. Neither HTLV I nor 111 can be considered as a cause of the LyP in any of our patients. Associated diseases were found in 6 cases (1 mycosis fungoides, 1 Hodgkin's disease, 2 anaplastic large-cell lymphoma and 2 large plaque parapsoriasis). Some types of parapsoriasis should be included in the 'spectrum of Ki-1 lymphomas'. 52 skin biopsies were studied. 17% were type A of Willemze, 67% were type B and 15% were transitional. In 12 of the samples follicular or perifollicular infiltration was found. Follicular LyP should not be considered as a distinct type of LyP. Vasculitis is an uncommon finding in LyP. In all the cases studied, large atypical cells were CD30 + ; 5/7 cases had lost CD5 and 4/5 cases had lost CD7. In one case, all T-cell antigens were negative. Cerebriform mononuclear cells were always recognized by T-cell antibodies and they were CD30 positive in only two cases. In one case there were more Correspondence to: . 206 CD8 + than CD4 + cells. In 5 patients skin and blood samples for genetic rearrangement (beta-T) were taken. Only germinal line was found. We did not find any significant difference between those cases in which malignant lymphoma developed and those in which it did not.