Figure 1.165. A close-up of the face of the same infant as in Figure 1.164 with familial progressive hyperpigmentation. Histopathologically the most distinctive manifestation consists of heavy melanization of the basal cell layers.

Figure 1.166. Note the marked hyperpigmentation in the skin of the mother of the infant shown in Fig. 1.165. Also note the pigmentation in the conjunctivae.

Figure 1.167. A pigmented nevus (junctional nevus) is a flat melanocytic nevus. The lesions are superficial, flat, discrete, brown, and hyperpigmented. There are usually a few lesions and they have a sharply demarcated border. Their color may vary from brown to black and they are caused by excessive numbers of melanocytes (nevocytes) at the dermal-epidermal junction. In some instances, proliferation of nevocytes down into the dermis occurs, giving rise to a raised, more or less darkly pigmented papular or verrucous lesion. These nevi are usually benign and the potential for malignant change is minimal but is greater for lesions that appear after birth.

Was this article helpful?

0 0

Post a comment