Primary cutaneous CD30-positive lymphoproliferative disorders (LPD) comprise a spectrum of disorders including lymphomatoid papulosis (LyP) and CD30+ pleomorphic or anaplastic large T-cell lymphomas ( 1 – 3 ). LyP is a chronic, recurrent lymphoproliferative disorder which manifests clinically as papulonodular, spontaneously regressing skin lesions ( 4 ). Histologically, large pleomorphic and anaplastic tumor cells are found which are activated T-lymphocytes expressing the CD30 antigen ( 5 , 6 ).
Viruses are known etiologic factors in the pathogenesis of non-Hodgkin’s lymphomas (NHL) ( 7 ). In particular, retroviruses such as human T-lymphotropic virus 1 and 2 (HTLV-1 and 2) have been linked to adult T-cell leukemia/lymphoma (ATLL) and other forms of NHL (for review see refs 8 and 9). Primary cutaneous lymphomas, especially cutaneous T-cell lymphomas, have been considered to be caused by viruses. Several reports of the detection of HTLV-1 or 2 sequences in cutaneous T-cell lymphomas (CTCL) ( 10 – 13 ) have not been confirmed in other studies ( 8 , 9 , 14 , 15 ).