Pathology · patient case with 1 question
Grey discolouration after a third molar extraction
Patient: 45-year-old patient at a follow-up visit.
Chief complaint: A dark mark on the gum where the tooth came out.
History: Maxillary third molar extracted some months ago. No pain, no change in size since it was first noticed.
Findings: A flat, bluish-grey, non-elevated pigmented area on the alveolar mucosa distal to the second molar. Adjacent teeth carry large amalgam restorations. The lesion does not blanch on pressure.
Question 1
What is the MOST likely diagnosis?
Show answer and explanation
Correct answer: A. Amalgam tattoo
- A. CORRECT. An AMALGAM TATTOO is metallic debris driven into the mucosa during restorative work or an extraction. It is flat, blue-grey to black, stable in size, asymptomatic, and typically adjacent to amalgam-restored teeth or a site where an amalgam-restored tooth was removed. Larger particles are visible on a radiograph, which confirms the diagnosis without a biopsy.
- B. A melanotic macule is brown from melanin, most often on the vermilion or gingiva, and is not associated with amalgam or an extraction site.
- C. A hemangioma is vascular and BLANCHES on pressure, which this lesion does not.
- D. Mucosal melanoma is a serious differential for any pigmented lesion, but it typically enlarges, may ulcerate, and shows irregular borders and colour variation. The stable size and the amalgam context point elsewhere. Biopsy anything that grows or changes.