Reflectance Confocal Microscopy and Dermoscopy for the Diagnosis of Solitary Hypopigmented Pink Lesions: A Narrative Review

Abstract

Diagnosing solitary pink skin lesions poses a significant challenge due to the scarcity of specific clinical and dermoscopic criteria. Several benign lesions, such as cherry angioma, clear cell acanthoma, dermal nevus, keloid, hypertrophic scar, and Spitz nevus, often exhibit similar clinical and dermoscopic features. This similarity extends to some malignant lesions, including basal cell carcinoma, actinic keratosis, and amelanotic melanoma, making differentiation difficult. Recent studies highlight the enhanced diagnostic accuracy of reflectance confocal microscopy (RCM), which offers increased sensitivity and specificity compared to dermoscopy alone for diagnosing skin cancer. This study aims to summarize the application of dermoscopy and RCM in distinguishing between benign and malignant pinkish-reddish skin lesions. The integration of RCM with traditional dermoscopic techniques improves the ability to accurately identify and differentiate these lesions. However, it is crucial to note that for any suspicious lesions, a final diagnosis must be confirmed through surgical excision and histopathological evaluation. This comprehensive approach ensures accurate diagnosis and appropriate treatment, highlighting the importance of combining advanced imaging techniques in clinical practice.

Keywords: Spitz nevus; actinic keratosis; amelanotic melanoma; basal cell carcinoma; cherry angioma; clear cell acanthoma; dermatofibroma; dermoscopy; pink lesions; reflectance confocal microscopy.

Figure 1

Cherry angioma. A 41-year-old woman presented with an erythematous papular lesion of the trunk. Dermoscopic image showing a well-demarcated pinkish lesion with white septa inside the lesion and red lacunes (a). RCM image with dark lacunes separated by bright septa (red arrow) (b). Courtesy, Anna Pogorzelska-Antkowiak, MD.

Figure 2

Clear cell acanthoma. A 38-year-old woman presented with an erythematous papular lesion on the left leg. Dotted vessels resembling a necklace and a scaly peripheral collarette in dermoscopy (a). At the level of the epidermis, the RCM image reveals acanthosis with papillomatosis (red arrow) in a well-defined lesion with a clear border (b). Courtesy, Prof. Caterina Longo.

Figure 3

Dermal nevus. A 54-year-old male with a nodular lesion of the abdomen characterized by comma-like vessels and residual pigmentation on dermoscopy (a). RCM image showing clusters of homogenous, dense, and sparse nests at the DEJ (red arrow) (b). Courtesy, Prof. Caterina Longo.

Figure 4

Dermatofibroma. A 36-year-old woman with a solitary, firm papule of the right deltoid. Small, central white scar-like area surrounded by a pinkish structureless zone in dermoscopy (a). RCM image showing thick reticulated collagen fibers in the central part of the lesion (red arrow) surrounded by edged and slightly bright papillae at the DEJ (red asterisk) (b). Courtesy, Prof. Caterina Longo.

Figure 5

Keloid. A 43-year-old male presented with a firm, nodular lesion on the right thigh. Dermoscopic image showing irregular vessels on a homogenous pinkish background (a). RCM image reveals numerous coarse collagen fibers (red arrow) (b). Courtesy, Prof. Caterina Longo.

Figure 6

Spitz nevus. A 14-year-old boy presented with a pinkish macular lesion on the left arm. Dermoscopy is characterized by an inverse pigment network, dotted vessels, and pigment remnants (a). (b) In RCM, the DEJ reveals edged and non-edged papillae with spindle-atypical cells and homogeneous nests (red arrow). Courtesy, Anna Pogorzelska-Antkowiak, MD.

Figure 7

Basal cell carcinoma. A 65-year-old man presented with a pinkish macular lesion of the dorsum. Dermoscopy reveals a pinkish, structureless area with thin telangiectatic vessels (a). RCM image showing a thick, elongated vessel (red asterisk) and a dark tumor island (red arrow) with palisading of nuclei and peritumoral clefts (b). Courtesy, Anna Pogorzelska-Antkowiak, MD.

Figure 8

Actinic keratosis. A 72-year-old male presented with an erythematous–desquamative macular lesion of the frontal region. The dermoscopic image shows a red pseudonetwork or strawberry pattern with white–yellow scales (a). RCM image showing an irregular honeycombed pattern of the epidermis indicative of moderate-grade dyskeratosis (red arrow) (b). Courtesy, Anna Pogorzelska-Antkowiak, MD.

Figure 9

Amelanotic melanoma. A 53-year-old woman presented with a hypopigmented-pink macular lesion with minimal residual pigment of the upper trunk. Dermoscopy shows linear irregular vessels and remnants of pigmentation (a). RCM at the level of the epidermis reveals numerous roundish (red arrow) and dendritic (red asterisk) pagetoid cells within a disarranged epidermis (b). Courtesy, Anna Pogorzelska-Antkowiak, MD.