Detection of desmoplastic melanoma with dermoscopy and reflectance confocal microscopy

Abstract

Background Desmoplastic melanoma (DM) is frequently misdiagnosed clinically and often associated with melanoma in situ (MIS). Objective To improve the detection of DM using dermoscopy and reflectance confocal microscopy (RCM). Methods A descriptive analysis of DM dermoscopy features and a case-control study within a melanoma population for RCM feature evaluation, performed blindly, using data obtained between 2005 and 2015. After retrospectively identifying all DM cases with RCM data over the study period (n=16), a control group of non-DM melanoma patients with RCM data, in a ratio of at least 3:1, was selected. The control group was matched by age and primary tumor site location, divided into non-DM invasive melanomas (n=27) and MIS (n=27). Invasive melanomas were selected according to the melanoma subtypes associated with the DM cases. The main outcomes were the frequency of melanoma-specific features on dermoscopy for DM; and the odds ratios of RCM features to distinguish DM from MIS and/or other invasive melanomas; or MIS from the combined invasive melanoma group. Results At least 1 of the 14 melanoma-specific features evaluated on dermoscopy were found in 100% of DMs (n=15 DM with dermoscopy). Known RCM melanoma predictors were commonly found in the DMs, such as pagetoid cells (100%) and cell atypia (100%). The RCM feature of spindle cells in the superficial dermis was more common in DM compared with the entire melanoma control group (OR 3.82, 95% CI 1.01–14.90), and particularly compared to MIS (OR 5.48, 95% CI 1.11–32.36). Nucleated cells in the dermis and the RCM correlate of dermal inflammation were also significant RCM features favouring DM over MIS, as well as invasive melanoma over MIS. Conclusion Dermoscopy and RCM may be useful tools for the identification of DM. Certain RCM features may help distinguish DM from MIS and other invasive melanomas. Larger studies are warranted.

Desmoplastic melanoma versus spindle cell melanoma

“…DM and SCM are 2 different rare subtypes of malignant melanoma and have similarities and differences in histologic and clinical features, and reflectance confocal microscopy features and immunohistochemistry are helpful tools for distinguishing them and others. [ 1 , 9 , 21 , 22 ] However, few literatures compare them in previous. To the best of our knowledge, this study is the first one to attempt to compare morbidity, clinicopathologic characteristic, treatment and outcome systematically in a large sample size.…”

Unusual Clinical Presentations of Malignant Melanoma: A Review of Clinical and Histologic Features with Special Emphasis on Dermatoscopic Findings

“…Dermatoscopy can be used in the first instance to facilitate recognition of key features of some unusual MM subtypes. In addition, reflectance confocal microscopy has emerged as a valuable diagnostic device in MM, guiding the clinician in the decision-making process [ 50 , 51 ]. Furthermore, the use of histopathology, with specific immunohistochemical markers, as well as specific genetic tests can help in establishing a solid diagnosis of an unusual type of melanoma.…”

Diagnostic accuracy of reflectance confocal microscopy for pigmented skin lesions presenting dermoscopic features of cutaneous melanoma

“…Digital monitoring utilizing sequential total body photography and videodermoscopy have been proven useful in early, often featureless melanomas. In hard-to-diagnose cases, the use of reflectance confocal microscopy is being proven to increase diagnostic specificity and sensitivity as a second-line examination tool in combination with classical or digital dermoscopy [4][5][6][7][8][9][10][11][12][13].…”

“…Due to near-histological resolution of the acquired images, it is becoming a valuable diagnostic tool in tertiary referral centers. Providing a strong contrast of melanin, the examination makes it possible to visualize melanocytes/melanophages – RCM is becoming popular in the pre-histological diagnosis of melanoma [ 10 , 14 – 16 ]. For the examination, a metal ring with a translucent template is placed on the surface of the skin lesion and fixed with special adhesive tape to stabilize the imaging.…”