AtlasPigmentedOral Melanotic Macule

Pigmented Lesions

Oral Melanotic Macule

aka Labial Melanotic Macule · Mucosal Melanosis

Benign, flat, well-circumscribed brown macule on oral mucosa due to increased melanin production without melanocyte proliferation.

Nature
Benign melanin increase
Site
Lower lip vermilion
Rx
Observe / biopsy if atypical

§ overviewOverview

Focal area of increased melanin deposition in basal layer without increase in melanocyte number.

§ icdICD Classification

L81.4

§ etiologyEtiology

  • 01Idiopathic
  • 02Post-inflammatory
  • 03Chronic irritation

§ epidemiologyEpidemiology

Most common pigmented lesion of oral cavity. Adults, F > M. Lower lip vermilion most common.

§ pathogenesisPathogenesis

Increased melanin production by existing melanocytes with pigment incontinence into lamina propria.

§ clinicalClinical Features

  • 01Flat, brown to black macule
  • 02Well-defined borders
  • 03Usually <1 cm
  • 04Non-elevated, non-palpable

§ differentialDifferential Diagnosis

  • 01Amalgam tattoo
  • 02Oral nevus
  • 03Early melanoma
  • 04Physiological pigmentation

§ histopathHistopathology

  • 01Increased melanin in basal layer
  • 02Melanophages in lamina propria
  • 03Normal melanocyte count

§ investigationsInvestigations

  • 01Biopsy if atypical features (irregular borders, rapid growth)

§ treatmentTreatment

  • 01Observation if clinical diagnosis confident
  • 02Excisional biopsy if doubt

§ prognosisPrognosis

Excellent; no malignant potential.

§ examKey Examination Points

  • 01Flat, well-circumscribed, stable size
  • 02Normal melanocyte number
  • 03Biopsy if atypical

§ revisionQuick Revision Summary

  • 01Most common oral pigmented lesion
  • 02Increased melanin, not melanocytes
  • 03Biopsy if suspicious

§ vivaBDS Viva Questions

  • 01How do you differentiate from melanoma?
  • 02What is the histology?
  • 03When would you biopsy?

§ mcqsMCQs — Assessment (3)

Question 1

Oral melanotic macule shows:

Question 2

Most common site for oral melanotic macule:

Question 3

Management:

References

  1. Neville BW. Oral & Maxillofacial Pathology, 4e

Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.