After extraction of an upper third molar, a bluish-grey discoloration is seen in the alveolar/gingival tissue just behind the second molar (which had amalgam restorations). No radiographic finding. What is the diagnosis?

Correct answer: B. Amalgam tattoo

• A. A hemangioma is a vascular lesion that typically BLANCHES with pressure (diascopy), unlike an amalgam tattoo.
• B. Correct. A bluish-grey, flat, asymptomatic mucosal stain adjacent to amalgam-restored/extracted teeth is an amalgam tattoo — metal particles implanted in the tissue during restoration or extraction. Radiographs may show radiopaque flecks (or nothing if particles are tiny).
• C. Melanoma is a malignant pigmented lesion; it is typically more irregular/enlarging, and the strong link to adjacent amalgam here points to a tattoo.
• D. A blue nevus is a benign melanocytic lesion but lacks the characteristic association with amalgam-restored/extracted teeth seen here.