Eosinophilic dermatosis of hematologic malignancy: Correlation of molecular characteristics of skin lesions and extracutaneous manifestations of hematologic malignancy.

BACKGROUND: Skin diseases are frequent in patients with chronic lymphocytic leukemia and other hematological neoplasias. Eosinophilic dermatosis of hematologic malignancy (ED) has long been considered a nonspecific cutaneous reaction pattern. Recently neoplastic cells have been shown to be present in ED thus challenging the classification as a nonspecific dermatosis.

METHODS: We report 5 patients with ED in association with chronic lymphocytic leukemia (CLL). We further investigated the presence of neoplastic B-cells in the skin infiltrate by immunohistochemistry and immunoglobulin heavy chain rearrangement and compared these to extracutaneous manifestations of CLL.

RESULTS: The phenotype of the lymphocytic infiltrate was predominately CD3+ (range: 60-90%). CD20+ and CD79a+ lymphocytes were less frequent accounting for up to 15% (range: absent - 15%). CD23+ lymphocytes represented up to 20% (range: absent - 20%) of the infiltrate. The analysis of the immunoglobulin heavy chain rearrangement in the skin specimens showed clonal rearrangements in 4/5 patients and in 3 of these 4 patients clones were identical to extracutaneous CLL manifestations.

CONCLUSION: Our data show that neoplastic B-cells are very frequently found in ED when systematically evaluated. This findings support the hypothesis that leukemic cells play a pathogenetic role in eosinophilic dermatosis of hematologic malignancy. This article is protected by copyright. All rights reserved.