The Many Roles of Dermoscopy in Melanoma Detection

Abstract

Dermoscopy is a non-invasive method of examination that aids the clinician in many ways, especially in early skin cancer detection. Melanoma is one of the most aggressive forms of skin cancer that can affect individuals of any age, having an increasing incidence worldwide. The gold standard for melanoma diagnosis is histopathological examination, but dermoscopy is also very important for its detection. To highlight the many roles of dermoscopy, we analyzed 200 melanocytic lesions. The main objective of this study was to detect through dermoscopy hints of melanomagenesis in the studied lot. The most suspicious were 10 lesions which proved to be melanomas confirmed through histopathology. The second objective of this study was to establish if dermoscopy can aid in estimating the Breslow index (tumoral thickness) of the melanomas and to compare the results to the histopathological examination. We found that the tumoral thickness may be estimated through dermoscopy, but the histopathological examination is superior. To conclude, the aim of this study was to showcase the versatility and many roles of dermoscopy, besides being one of the most important tools for early melanoma diagnosis.

Keywords: dermoscopy; melanoma; melanomagenesis; nevi; tumoral thickness.

Figure 1

Main melanoma subtypes. (A). Superficial spreading melanoma (SSM). (B) Nodular melanoma (NM). (C). Lentigo maligna melanoma (LMM).

Figure 2

Dermoscopic and histopathologic aspects of melanoma. (A). Superficial spreading melanoma (SSM)—Main dermoscopic criteria—asymmetrical melanocytic lesion, with atypical network, eccentric hyperpigmented areas, irregular dots/globules, irregular streaks/pseudopods, central blue-white veil, regression structures. Histopathologic description—SSM without ulceration, BI (Breslow index) = 0.5 mm (pT1a), Clark level II, developed on a preexisting nevus—atypical melanocytes located in the dermal-epidermal junction, with pagetoid ascension. (B). Lentigo maligna melanoma (initial lesion)—Main dermoscopic criteria—asymmetrical melanocytic lesions with irregular dots/globules, eccentric hyperpigmented area, and regression structures. Histopathologic description: complete regression of the lentiginous component of a lentigo maligna melanoma—flattened epidermis, severe dermal solar elastosis, melanophages deposited in a band-like in the papillary dermis. Immunohistochemistry—Melan A and SOX 10—melanocytes with quasi-normal characteristics and disposition in the basal layer of the epidermis. (C). Lentigo maligna melanoma (vertical growth phase, recurrence after 8 months on the post-operative scar)—Main dermoscopic criteria—atypical vascular pattern, eccentric hyperpigmented area, regression structures. Histopathologic description—LMM (vertical growth phase) without ulceration, BI = 2.2 mm (pT3a), Clark level IV—atypical melanocytes arranged lentiginously and in nests at the dermo-epidermal junction, with pagetoid invasion in the epidermis. Immunohistochemistry—Melan A and Tyrosinase—positive. Histopathologic images—provided through the courtesy of Dr. Tiberiu Tebeică, Dr. Leventer Centre—Bucharest, Romania.