Histopathologic examination of a papule showed a wedge-shaped dense infiltrate involving the entire dermis and composed of medium- to large-sized atypical lymphocytes. The atypical lymphocytes were admixed with histiocytes, small lymphocytes, and neutrophils and had abundant cytoplasm and prominent nucleoli. Immunohistochemical investigations revealed that the atypical lymphoid cells stained positively for anti-CD3, -CD4, -CD45RO, and -CD30 (Figure 4) antibodies. These features were consistent with type A LyP.
Widespread Recurrent Lichenoid Papular Eruption—Diagnosis. Arch Dermatol. 2004;140(4):479-484. doi:10.1001/archderm.140.4.479-d