Definition: Lentigo maligna, or Hutchinson’s freckle, is a premalignant lesion of melanocytes that probably, represents in-situ melanoma.
Clinical features: Lentigo maligna is very rare intraorally. Clinically, it appears as a slowly expanding black or brown plaque, with irregular borders (Fig..89). In 5-15 years, it ultimately progresses into invasive melanoma. The lips, buccal mucosa, palate, and floor of the mouth are the common sites affected.
Laboratory tests: Histopathological examination.
Differential diagnosis: Melanoma, pigmented nevi, amalgam tattoo.
Treatment: Surgical excision, radiotherapy.