In vivo reflectance confocal microscopy to monitor the response of lentigo maligna to imiquimod

J Am Acad Dermatol. 2014 Jul;71(1):49-55. doi: 10.1016/j.jaad.2014.02.043. Epub 2014 Apr 13.

Abstract

Background: Imiquimod has been used for treating lentigo maligna (LM) in selected cases when surgery is not an appropriate option because of functional or aesthetic impairment. Reflectance confocal microscopy (RCM) is a noninvasive method that has not been validated for monitoring the treatment of LM with imiquimod.

Objective: We sought to evaluate the use of in vivo RCM to accurately monitor the response of LM to nonsurgical treatment with topical imiquimod.

Methods: Twenty patients with confirmed facial LM, not amenable to surgical treatment or radiation therapy, were included prospectively. Clinical evaluation was performed by dermoscopy, RCM, and histopathology. Patients applied imiquimod 5% for 8 weeks. The affected area was assessed using the previously described LM score on RCM, and target sample biopsies were performed to confirm or discard RCM findings.

Results: Fifteen of the 20 patients (75%) presented histologic tumor clearance. Confocal microscopy identified 70% of these responders with no false-negative results, and when compared with histopathology, there was no significant difference in evaluating the response to imiquimod.

Limitations: The impossibility of examining the entire lesion by means of histopathology is a limitation.

Conclusion: In vivo RCM evaluation was useful in accurately monitoring the response of LM to nonsurgical treatment with topical imiquimod in patients when surgery is contraindicated.

Keywords: dermoscopy; imiquimod; lentigo maligna; melanoma; noninvasive diagnosis; nonsurgical treatment; reflectance confocal microscopy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Adjuvants, Immunologic / therapeutic use*
  • Adult
  • Aged
  • Aged, 80 and over
  • Aminoquinolines / administration & dosage
  • Aminoquinolines / therapeutic use*
  • Dermoscopy
  • Facial Neoplasms / drug therapy*
  • Female
  • Humans
  • Hutchinson's Melanotic Freckle / drug therapy*
  • Imiquimod
  • Male
  • Microscopy, Confocal / methods*
  • Middle Aged
  • Off-Label Use
  • Prospective Studies
  • Skin Neoplasms / drug therapy*

Substances

  • Adjuvants, Immunologic
  • Aminoquinolines
  • Imiquimod