Surveillance for treatment failure of lentigo maligna with dermoscopy and in vivo confocal microscopy: new descriptors

Authors

  • P. Guitera,

    Corresponding author
    1. Melanoma Institute Australia, Poche Centre, North Sydney, NSW, Australia
    2. Department of Sydney Melanoma Diagnostic Centre, NSW, Australia
    3. Discipline of Dermatology, The University of Sydney, Sydney, NSW, Australia
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  • L.E. Haydu,

    1. Melanoma Institute Australia, Poche Centre, North Sydney, NSW, Australia
    2. Discipline of Surgery, The University of Sydney, Sydney, NSW, Australia
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  • S.W. Menzies,

    1. Department of Sydney Melanoma Diagnostic Centre, NSW, Australia
    2. Discipline of Dermatology, The University of Sydney, Sydney, NSW, Australia
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  • R.A. Scolyer,

    1. Melanoma Institute Australia, Poche Centre, North Sydney, NSW, Australia
    2. Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
    3. Discipline of Pathology, The University of Sydney, Sydney, NSW, Australia
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  • A. Hong,

    1. Melanoma Institute Australia, Poche Centre, North Sydney, NSW, Australia
    2. Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
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  • G.B. Fogarty,

    1. Melanoma Institute Australia, Poche Centre, North Sydney, NSW, Australia
    2. Discipline of Pathology, The University of Sydney, Sydney, NSW, Australia
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  • F. Gallardo,

    1. Department of Dermatology, Hospital el Mar, Barcelona, Spain
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  • S. Segura

    1. Department of Dermatology, Hospital el Mar, Barcelona, Spain
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  • Funding sources This study was supported by the Melanoma Institute Australia, the Melanoma Foundation of the University of Sydney, and the Australia and New Zealand Melanoma Trials Group.
  • Conflicts of interest None.

Summary

Background

Nonsurgical treatment (radiotherapy, imiquimod) is increasingly employed for the management of lentigo maligna (LM). While the diagnosis of LM remains difficult, the detection of treatment failure is even more challenging.

Objectives

To describe the sensitivity and specificity for the diagnosis of LM of individual features and methods using dermoscopy and in vivo reflectance confocal microscopy (RCM) to aid in the detection of treatment failure of LM following nonsurgical treatment.

Methods

A retrospective study of dermoscopy and RCM images (blinded to the correlation with pathology) in patients with biopsy-confirmed LM who were undergoing nonsurgical treatment in two referral institutions – one in Sydney, Australia, and the other in Barcelona, Spain. Ninety-eight patients were treated nonsurgically for LM during the period 2006–2012. Thirty-one patients had abnormal dermoscopy or RCM evaluation, and had a biopsy that identified LM recurrence in 15 patients and nonmelanoma diagnoses in 16 patients (one Bowen disease, 15 solar changes).

Results

The diagnosis of treatment failure was difficult with dermoscopy, with a sensitivity of 80% and specificity of 56%, even with the interpretation of an expert. The best criterion was asymmetric hyperpigmented follicular openings, but this was present in only 47% of treatment failure LM. Isolated, very fine brown dots (‘dust’ appearance) correlated highly with the diagnosis of treatment failure LM (73% sensitivity and 88% specificity) and with pagetoid cells seen with RCM. The LM score, comprising six criteria, had a specificity of 94% and sensitivity of 100%.

Conclusions

These methods and descriptors should help to manage the diagnosis of treatment failure.

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