Hyperpigmented plaque with raised border at right angle of mouth involving oral mucosa

A 17-year-old female presented with an asymptomatic circular plaque on the right angle of mouth which was progressively increasing in size over a span of eighteen months. On examination a circular plaque with a diameter of about 2.5 cm with a raised hyperkeratotic border and atrophic center involving the right angle of mouth and extending into the lip and mucosa was seen ( Figure 1 ). There were no lesions elsewhere in body and family history was non-contributory. A biopsy was taken from the advancing edge of the lesion over the lip and was sent for histopathology where it was stained with hematoxylin-eosin (H & E)