[Assessment of the significance of histological, immunohistochemical and clinical data in the diagnosis of lymphoproliferative skin diseases in conformance with a consensus by international experts].
ABSTRACT The diagnosis of lymphoproliferative diseases of the skin remains a challenging problem in dermatology and requires a multidisciplinary approach. In our retrospective study two dermatopathologists independently reviewed 49 cases of skin lymphomas to determine the impact of diagnostic methods such as clinical examination, histological evaluation, and immunohistochemistry. The study was carried out in four independent review sessions consisting of (1) a review of histological sections only, (2) a review of immunohistochemical sections, (3) an introduction of the detailed clinical data, history, and staging information, and (4) and introduction of the follow-up. The agreement with the consensus was analyzed for every session, and statistics were calculated to evaluate the interobserver reliability. The agreement level with the consensus diagnosis was 18.8% for B-cell lymphomas and 12.5% for T-cell lymphomas after the first session, respectively, improved to 56.3% and 43.8% after the second session; to 100% and 79.7% after the third session, and to 100% and 85.9% after the forth one. The overall value for the diagnosis of T-cell lymphomas was 0.67 (good consensus) and for that of B-cell lymphomas was 1.00 (absolute consensus). The results of our study show that cutaneous lymphomas can be diagnosed reliably basing on the overall assessment of the clinical, histopathological, and immunohistochemical data. In some cases, however, molecular biologic methods may be required to diagnose cutaneous lymphomas properly.