In vivo reflectance confocal microscopy for evaluating common facial hyperpigmentation

Abstract

Background In clinical settings, atypical facial hyperpigmentation such as nevus of Ota, acquired bilateral nevus of Ota‐like macules (ABNOM), melasma, and café‐au‐lait spots are often missed and misdiagnosed. Summarizing in vivo reflectance confocal microscopy (RCM) features of the hyperpigmentation is helpful in the diagnosis of ambiguous lesions. Methods We recruited 196 patients referred for unequivocal facial hyperpigmentation, including 55 patients with nevus of Ota, 45 patients with ABNOM, 62 patients with melasma, and 34 patients with café‐au‐lait spots. The RCM images were evaluated at the epidermis, the dermis‐epidermis junction (DEJ), and the upper papillary dermis from both hyperpigmented patches and normal skin. Results In the superficial and middle dermis, 41 of 55 patients (74.5%) with nevus of Ota were characterized by a cord‐like or lumpy structure between the collagen fibers. And there was no melanin deposition detected in the dermis in 14 of 55 (25.5%) patients. In ABNOM, 37 of 45 (82.2%) patients were characterized by a cord‐like or lumpy structure in the superficial dermis and 8 of 45 patients (17.8%) was no melanin deposition detected in the dermis. The epidermis was no difference between nevus of Ota, ABNOM, and the normal skin. Melasma was detected increased cobblestone pattern in the epidermis of all patients, branching architecture in 21 of 62 patients (33.9%), and focally aggregated round to triangular cells in the upper dermis of 18 of 62 patients (29.0%). In all patients with afé‐au‐lait spots, increased cobblestone pattern in the epidermis and regular and increased density of ringed pattern in the DEJ were visualized. Conclusions Our findings indicate that RCM may be useful in the auxiliary diagnosis of nevus of Ota, ABNOM, melasma, and café‐au‐lait spots.

Computer-Aided Detection (CADe) System with Optical Coherent Tomography for Melanin Morphology Quantification in Melasma Patients

“…Imaging modalities aid the diagnosis, monitoring, and treatment response for many conditions, especially precancer lesions and skin cancers [6,31,32]. These techniques have further expanded the field of cosmetic dermatology in detecting clinically undetectable cell changes of the skin, affording new insights into the mechanisms and kinetics of pigmentary disorders [3,10,33,34]. Although FF-OCT provides dermatologists real-time cellular images, naked-eye evaluation is subject to weariness and inter-and intra-observer variability.…”

“…Dark skin-type individuals have more hyperactive melanocytes compared to the fair skin-type individuals and are prone to develop melasma and other pigmentary disorders [1][2][3]. The deposit of melanin in keratinocytes is readily seen on hematoxylin and eosin stain (H&E stain), while melanocytes must be identified by special staining.…”

“…The deposit of melanin in keratinocytes is readily seen on hematoxylin and eosin stain (H&E stain), while melanocytes must be identified by special staining. With the emerging non-invasive techniques, melanin in the epidermis can be easily visualized because of its brightness by dermatofluoroscopy [4], reflectance confocal microscopy (RCM) [3], multiphoton microscopy [5], and optical coherence tomography (OCT) [6]. Studies suggested melanocytes rapidly transfer the produced melanin to keratinocytes rather than accumulating it [7].…”

“…Melanin amount and distribution are therefore commonly used to classify the melasma subtypes and to monitor the treatment response [10]. Non-invasive techniques including RCM and multiphoton microscopy already detect pigmentary changes after treatment with the picosecond alexandrite laser and Q-switched Nd: YAG laser [3,5,10,11]. We recently demonstrated the cellular resolution full-field optical coherence tomography (FF-OCT) system allows real-time, non-invasive imaging of superficial skin diseases [6].…”

The pathogenesis of melasma and implications for treatment

“…[21][22][23] In vivo reflectance confocal microscopy revealed increased melanin-containing cells in the granular, spinous, and basal cell layers. 24 Clinically, melasma is classified by means of Wood's lamp as being epidermal, dermal, or mixed; however, biopsies from melasma lesions of all types display melanin in both epidermis and dermis. It is assumed that disruption of the BM facilitates the descent of melanocytes and melanin into the dermis, appearing as free pendulous melanocytes or melanophages that are frequently observed in the dermis of melasma skin.…”