Elsevier

Dermatologic Clinics

Volume 19, Issue 2, 1 April 2001, Pages 299-305
Dermatologic Clinics

A METHOD FOR THE DIAGNOSIS OF PRIMARY CUTANEOUS MELANOMA USING SURFACE MICROSCOPY

https://doi.org/10.1016/S0733-8635(05)70267-9Get rights and content

In vivo cutaneous surface microscopy (epiluminescence microscopy, dermoscopy, dermatoscopy, magnified oil immersion diascopy) increases the diagnostic accuracy for the majority of pigmented skin lesions, including melanoma.2, 3, 9, 10, 11, 12, 13, 14 However, few surface microscopy methods for the diagnosis of melanoma have been formally described and tested for their sensitivity and specificity using an independent test set.1, 4, 7, 9 A method that gives a sensitivity of 92% and specificity of 71% has previously been described for the diagnosis of invasive melanoma.7 The method is simple, with 11 features being used to create the model. All features can be visualised with standard ×10 magnification hand-held surface microscopes (e.g., Dermatoscope Heine Ltd, Episcope Welch Allyn Inc) and are scored as categorical (i.e., present or absent), which reduces the intra- and interobserver errors seen when features are graded. Finally, an atlas has been produced that allows even inexperienced clinicians to learn the method.5 This enabled primary care physicians to increase their sensitivity for the diagnosis of melanoma by 20%.14 The following gives a detailed description of the method.

Section snippets

METHOD DEVELOPMENT

A training set of 62 invasive melanomas and 159 clinically atypical pigmented nonmelanomas were scored for 72 surface microscopic features.8 The nonmelanoma set included nonmelanocytic lesions, such as seborrheic keratoses, hemangiomas, and dermatofibromas. To create the model, individual features were selected with low sensitivity (0%) for melanoma, defining the two “negative features”, or high specificity (>85%) for melanoma, defining the 9 “positive features.”7 This diagnostic method (Table

THE METHOD

For a melanoma to be diagnosed, it must have neither of the two morphologic negative features and one or more of the nine positive features. The following describes each feature.5

FALSE-NEGATIVE MELANOMAS

Although 92% of invasive melanomas can be diagnosed using this method, 8% fail to be diagnosed using the above criteria.7 These can be divided into two categories: some early, thin, pigmented melanomas, and hypomelanotic melanomas. The latter defines an important group because it may not be thin on presentation. These melanomas often are highly vascular, with pin-point, hairpin, or less commonly, arborising telangiectasia. This vascularity often can distinguish these lesions from benign nevi (

IN-SITU MELANOMA

Lentigo maligna or other variants of in-situ melanoma can be diagnosed using the above method because they frequently have the positive features of broadened network and, to a lesser extent, multiple blue-gray dots. Less frequently, multiple brown dots, peripheral black dots, pseudopods, and radial streaming may be present; however, as yet, the method has not been formally tested on a large series of in situ melanoma.

References (14)

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Address reprint requests to Scott W. Menzies, MBBS, PhD Sydney Melanoma Unit, Royal Prince Alfred Hospital Missenden Rd Camperdown NSW 2050, Australia [email protected]

*

Department of Surgery, University of Sydney; and the Sydney Melanoma Unit, Melanoma and Skin Cover Research Institute, Royal Prince Alfred Hospital, New South Wales, Australia

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