Photo Derm Diagnosis: 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 noncontributory. 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) [Figure 2].