Lymphomatoid Papulosis Histopathologically Simulating Angiocentric and Cytotoxic T-cell Lymphoma

We report a patient presenting with a 20-year history of recurrent papulonecrotic lesions in which skin biopsy shows extensive vascular destruction. Atypical lymphoid cells surrounding the dermal vessels had a CD3+, CD4-, CD5-, CD8+, CD20-, CD30+, CD56+, TIA-1+, and granzyme B immunophenotype implicating a natural killer/T origin. In situ hybridization was negative for Epstein-Barr virus transcripts. Analysis of T-cell receptor-gamma gene of 2 separate biopsy specimens detected an identical clone. The patient was treated with low-dose methotrexate and achieved complete resolution in a month. According to the clinical course, immunophenotype, clonality analysis and the excellent response to methotrexate, we conclude that this is an unusual case of lymphomatoid papulosis. We believe that this unusual presentation needs to be distinguished from other aggressive lymphomas, including the natural killer/T-cell and cytotoxic T-cell subsets.