Angioimmunoblastic T cell lymphomas: frequent cutaneous skin lesions and absence of human herpes viruses.

BACKGROUND: Angioimmunoblastic T-cell lymphoma (AITL) is a complex lymphoproliferative disorder and often mimics a viral infection with frequent skin involvement. Epstein-Barr virus (EBV) and human herpes virus (HHV)-6 are reported to be associated with AITL, but there are conflicting results.
OBJECTIVE: We evaluated the association of EBV and HHV-6 with AITL.
METHODS: We reviewed the clinical, histological and immunophenotypical features of 19 cases of AITL. Among them, 11 lymph node biopsies of AITL were examined for HHV-6, -7, and -8 by polymerase chain reaction (PCR) using virus-specific primers. In situ hybridization of EBV early region RNA (EBER) was performed and T cell receptor (TCR) gene rearrangement was also investigated in some cases.
RESULTS: Among these 19 cases, maculopapular, plaque or nodular skin lesions accompanied AITL in 12 cases. Clonal TCR gene rearrangement was seen in 8/9 cases tested. EBER in situ hybridization was positive in 8 cases (57.1%). Among 7 cases with skin biopsies, five cases were consistent with cutaneous involvement of AITL, 1 case was a drug eruption, and the other case was Kaposi's sarcoma. Except a HHV-8 (+) case who also had Kaposi's sarcoma, all of these cases were negative for HHV-6, -7 and -8.
CONCLUSION: Skin manifestation seems to be a cardinal component of AITL, be it in the context of presentation, progression or recurrent disease. Recognition of clinicopathological features of skin lesions in AITL as diagnostic clues should be stressed among dermatologists. The lack of HHV-6, -7 and -8 in lymph node biopsy of AITL argues against a pathogenic role for HHVs in AITL.