Detection of HTLV-I proviral DNA in sarcoidosis

'Sarcoidosis-lymphoma syndrome' is known as an association of sarcoidosis with malignant lymphoma. We report a 56-year-old woman with systemic sarcoidosis who was seropositive for antibody against human T cell lymphoma/leukemia virus type I (HTLV-I). This patient showed integration of HTLV-I proviral DNA within cutaneous sarcoid nodules, but not in peripheral blood mononuclear cells. Neither atypical lymphocytes nor a T cell receptor beta1 gene rearrangement were observed in peripheral blood mononuclear cells or in cutaneous nodules, indicating that the patient did not have a smouldering type of adult T cell lymphoma/leukemia. Detection of integration of HTLV-I proviral DNA in cutaneous sarcoid nodules could suggest that the sarcoid nodules might have been generated as a protective response to chronic stimuli of HTLV-I.