Immunohistochemical features in inflammatory linear verrucous epidermal nevi suggest a distinctive pattern of clonal dysregulation of growth. Military Medical Consortium for the Advancement of Retroviral Research.

BACKGROUND

We studied biopsy material from four patients with inflammatory linear verrucous epidermal nevi (ILVEN) that had a psoriasiform appearance histologically and seven cases of linear epidermal nevi (LEN). Of the seven LEN, five showed hyperkeratosis, papillomatosis, and varying degrees of acanthosis; two had features of epidermolytic hyperkeratosis. Because these lesions have distinctive histologic patterns, we wanted to determine whether we could also demonstrate a distinctive pattern of immunohistochemical markers.

METHODS

On all 11 cases we performed immunohistochemical stains for PCNA, factor XIIIa, MAC-387, UCHL-1, and OPD-4. In addition, on one case of ILVEN we performed ICAM-1, ELAM-1, and HLA-DR stains.

RESULTS

The pattern of staining of PCNA, factor XIIIa, MAC-387, UCHL-1, and OPD-4 was distinctly different in ILVEN and LEN. Staining for ICAM-1 was present on keratinocytes, and ELAM-1 was present on endothelial cells in two cases of ILVEN. HLA-DR in these same two cases of ILVEN stained mainly dendritic cells in the epidermis.

CONCLUSION

The different pattern of staining of PCNA, factor XIIIa, MAC-387, UCHL-1, and OPD-4 in LEN and ILVEN indicates a different mechanism of growth dysregulation. Stains for ICAM-1, ELAM-1, and HLA-DR in ILVEN suggest that an inability to down-regulate the inflammatory infiltrate may be important in the growth dysregulation in ILVEN. In addition, the onset of ILVEN at the time of HIV-1 infection in one patient suggests that HIV-1 infection may be one of many factors that initiates ILVEN in a susceptible person.