Treatment

Under local anesthesia two separate biopsies were performed. Based on the histology, no treatment was rendered. Close clinical follow-up was recommended.

Incisional and excisional biopsy

Both buccal mucosal biopsies demonstrated non-neoplastic stratified squamous epithelium with basal layer hyperpigmentation and increased deposition of dark-brown pigment granules predominantly in histiocytes and freely in the stromal matrix of the superficial lamina propria. The pigment granules were stained with a Fontana-Masson stain, but were negative for iron stain. Nevertheless, melanocytic hyperplasia was not appreciated by S100 and Melan-A immunohistochemical stains.

Figure 2 Low power (100X) H & E histology representative of both biopsies. The buccal mucosa demonstrates non-neoplastic epithelial hyperplasia with basal cell layer hyperpigmentation and increased deposition of dark-brown pigment granules in the superficial lamina propria

 

Figure 3 High power (400X) Fontana-Masson stain is positive for melanin pigment at the basal cell layer and superficial lamina propria. Dendritic psuedopods are identified in the basal and parabasal cell layers.

Figure 4 High power (400X) immunohistochemistry stain with Melan A is negative for melanocytic hyperplasia. Melanin pigment is present in the basal cell layer and superficial lamina propria. Similar morphology was identified with S100 protein antibody. Dendritic psuedopods are identified in the basal and parabasal cell layers..