Regressing atypical histiocytosis and lymphomatoid papulosis: variants of the same disorder?

We report a patient with lymphomatoid papulosis who developed a lesion with the clinicopathological features of regressing atypical histiocytosis. Immunohistochemical studies supported a T-cell histogenesis and many of the atypical cells demonstrated BerH2 (Ki-I antigen) positivity. The case supports the view that regressing atypical histiocytosis and lymphomatoid papulosis are different manifestations of the same disease spectrum.