Indolent CD8+ lymphoid proliferation of the ear: report of two cases and review of the literature

Indolent CD8+ lymphoid proliferation of the ear is a recently described cutaneous lymphoid proliferation that clinically presents with slow growing lesion(s) on the ear(s). In cases reported to date, there has been indolent clinical behavior and no evidence of systemic involvement. Characteristic histopathologic features include a non-epidermotropic diffuse dermal infiltrate of CD8+ T-lymphocytes with a lymphoblast-like appearance. T-cell clonality has also been observed. Herein, we present two patients who show clinical, histopathologic and immunophenotypic features similar to the original index cases described by Petrella et al. In addition, we review the literature regarding this unusual lymphoid proliferation and provide evidence that this entity represents a phenotypic variant of primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma, a concept proposed by Beltraminelli et al. in 2009. Differentiation between this lymphoproliferative process and other more aggressive CD8+ lymphomas is essential in avoiding excessive treatment of a condition that combines worrisome histopathology with indolent clinical behavior.