Reticulate hyperpigmentation of the skin can be seen in a variety of disorders, sometimes with significant clinical overlap.1 Genital lentiginosis can be seen as dark macules. We report 2 cases of reticulate pigmentation that cannot be classified in any of the conditions known to us to have been described.
A 21-year-old man with palmar psoriasis had asymptomatic reticulate pigmentation of the genitalia since birth; in the last months before we saw him, achromic macules inside the pigmented areas appeared and remained stable. He had no similar lesions in other sites and no affected relatives. The lesions were very well demarcated, dark, reticulate pigmentation affecting the scrotum and the penis shaft, without infiltration or epidermal changes (Figure 1). Two biopsy specimens showed basal layer hyperpigmentation without an increased number of melanocytes and with scarce melanophages in the papillary dermis (pigmented area). The epidermis was normal, without melanic globules or melanocytes, as confirmed by melan-A testing (achromic area). Localized vitiligo was diagnosed.
Romero-Maté A, Miñano-Medrano R, Nájera-Botello L, Castaño-Pascual Á, Martíinez-Morán C, Borbujo J. Reticulate Genital Pigmentation Associated With Localized Vitiligo. Arch Dermatol. 2010;146(5):574-575. doi:10.1001/archdermatol.2010.69