Erythroderma Part I. Erythrodermic form of cutaneous T-cell lymphoma (CTCL)

Abstract

Erythrodermic cutaneous T-cell lymphoma (E-CTCL) includes erythrodermic (E) mycosis fungoides (E-MF) and Sézary syndrome (SS), considered to be two distinct clinical entities, although related. Clinical characteristics of E-MF and SS are similar, with a hallmark of erythroderma and varying numbers of Sézary cells in the blood. Distinguishing between E-MF and SS relies on determining the degree of blood involvement, based on the expanded criteria for B classification from the ISCL-EORTC. Epidermotropic infiltrate of atypical, monoclonal, CD4+ lymphoid cells can be present in both dise ases with minor differences in the quantity of the infiltrating cells, in dermal changes, and in the presence of nonspecific histology. Clinicopathologic findings can be subtle and may mimic benign dermatoses. Thus, immunohistochemistry, molecular analysis, and blood flow cytome try are essential for accurate diagnosis.