Derm Dx: Dark spots on the lip - Clinical Advisor

Derm Dx: Dark spots on the lip

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A 33-year-old woman requests consultation for dark spots that have been present on her lip for several years. One of the discolorations was biopsied elsewhere and was reported to her as benign. The patient denies antecedent medication use, including minocycline. Examination reveals 2 well-demarcated black macules on her lower lip as well as a similar lesion on the buccal mucosa. She is fair-skinned and has scattered lentigines on her chest and back. 

Labial macules occur most frequently in women who are fair-skinned and have had ample sun exposure. They characteristically present in the third decade of life and appear as well-defined dark brown to black macules on the lower lip, ranging in...

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Labial macules occur most frequently in women who are fair-skinned and have had ample sun exposure. They characteristically present in the third decade of life and appear as well-defined dark brown to black macules on the lower lip, ranging in size from 2 to 6 mm. The condition was first reported in 1976,1 and one study noted an incidence of 3% in immunocompetent individuals.2 The macules may also occur in those with Laugier-Hunziker syndrome in conjunction with nail pigmentation.3

Histopathology of a labial macule reveals prominent basilar hyperpigmentation accentuated at the tips of the rete ridges without atypia or nevoid formation.4 The lesions are benign and have no malignant potential but can engender cosmetic disfigurement. Similar to lentigines, labial macules may respond to liquid nitrogen cryosurgery5 or laser therapy.6

 

Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.

References

  1. Weathers DR, Corio RL, Crawford BE, Giansanti JS, Page LR. The labial melanotic macule. Oral Surg Oral Med Oral Pathol. 1976;42:196-205.
  2. Ficarra G, Shillitoe EJ, Adler-Storthz K, et al. Oral melanotic macules in patients infected with human immunodeficiency virus. Oral Surg Oral Med Oral Pathol. 1990;70:748-755.
  3. Laugier P, Hunziker N. Pigmentation melanique lenticulaire essentielle de la muqueuse jugale et des levres. Arch Belg Dermatol Syphiligr. 1970;26:391-399.
  4. Ho KK, Dervan P, O’Loughlin S, Powell FC. Labial melanotic macule: a clinical, histopathologic, and ultrastructural study. J Am Acad Dermatol. 1993;28:33-39.
  5. Ortonne JP, Pandya AG, Lui H, Hexsel D. Treatment of solar lentigines. J Am Acad Dermatol. 2006;54(5 Suppl 2):S262-S271.
  6. Ozawa T, Fujiwara M, Harada T, Muraoka M, Ishii M. Q-switched alexandrite laser therapy for pigmentation of the lips owing to Laugier-Hunziker syndrome. Dermatol Surg. 2005;31:709-712.
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