The clinicopathologic features of 14 patients with angioimmunoblastic lymphadenopathy (AIL)-related lesions were analyzed. Lymph node biopsy specimens from all the patients showed a diffuse obliteration of lymph node architecture, prominent vascular proliferation, a polymorphous cellular infiltrate, including immuno-blasts, and varying degrees of clear cell proliferation. The patients were eight males and six females, with a median age of 58.5 years. All but one were in an advanced stage at the time of diagnosis. Bone marrow involvement was observed in eight patients. Thirteen patients had a negative serologic reaction for antibody to human T-cell leukemia virus type I (HTLV-I), and one patient was considered to be a HTLV-I carrier. Polyclonal hypergammaglobulinemia was observed in 6 patients, and 6 of the 12 patients showed elevated IgE levels. Immunophenotyping of the involved lymph nodes revealed a preponderance of T-cells in all the patients. Eleven of these patients showed a predominance of CD4+ over CD8+ T-cells, and only one patient showed a predominance of CD8+ over CD4+ T-cells. Two of five patients whose gene analysis was carried out showed clonal rearrangement of the T-cell receptor beta chain gene without rearrangement of the immunoglobulin heavy chain genes. Twelve patients received doxorubicin-containing combination chemo therapy; of these, 7 patients achieved complete response, and the other 5 had partial response. Nine patients are still alive with a median follow-up period of 21 months, and five patients died during the follow-up period. Progression to high-grade T-cell lymphoma with systemic infiltration was ascertained in two of three cases for which autopsy was performed. From our experience, we recommend doxorubicin-containing combination chemotherapy as initial therapy for AIL-related lesions.