Nest-shaped or microabscess-like accumulations of atypical lymphocytes in the epidermis as an expression of epidermotropy and "homing in" of the cells (see also microabscesses). This phenomenon is typically found in epidermotropic cutaneous T-cell lymphomas (e.g. in mycosis fungoides and Sézary syndrome).
The term is a misnomer, as an abscess by definition consists of neutrophil granulocytes.