The clinical and histological spectrum of lymphomatoid papulosis.

A review of sixty-four biopsies from sixteen patients with lymphomatoid papulosis revealed two characteristic histological types (type A and type B), which also had a different clinical behaviour. In lymphomatoid papulosis type A lesions, four histological patterns corresponding with the age of the lesion could be distinguished. Such a relationship was not found in type B lesions. The findings of transitional forms in some biopsy specimens, showing histological features of both type A and type B, and the presence of both types in different but concurrent lesions, suggests that these two types are not different entities but rather represent the ends of a spectrum. At least two different populations of atypical cells can be distinguished in lymphomatoid papulosis. Apart from the atypical cerebriform mononuclear cells, which are T-lymphocytic in origin and predominant in type B lesions, large atypical cells with vesicular nuclei, prominent nucleoli and abundant cytoplasm are found, particularly in type A lesions. Preliminary immunohistochemical and cytochemical investigations suggest that these cells are not lymphoid in origin, but are related to the Langerhans cell series.