The combined role of clinical, reflectance confocal microscopy and dermoscopy applied to chronic discoid cutaneous lupus and subacutus lupus erythematosus: A case series and literature review

Line-field confocal optical coherence tomography: Characteristic hints for the diagnosis of scarring alopecia due to lupus erythematodes: A preliminary study

INTRODUCTION

Lupus erythematosus (LE) is an inflammatory autoimmune disease, that can affect the skin to varying degree. In particular, discoid LE (DLE) and the rare form of lupus panniculitis/profundus are associated with scarring alopecia. The heterogeneity of the clinical, dermatoscopic, and histologic presentation poses a major challenge to the clinician in the diagnosis and differential diagnosis of other forms of scarring alopecia.

OBJECTIVE

While noninvasive imaging techniques using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) have proven to be helpful in the diagnosis of scarring alopecia in the context of LE, this study aimed to investigate line-field confocal OCT (LC-OCT) to identify characteristic features of cicatricial alopecia in LE.

METHODS

Fifteen patients with cicatricial alopecia in LE were included and the most affected/inflamed areas of the scalp were prospectively examined. In analogy to histopathology and previously reported criteria in RCM, all images were evaluated according to seven established criteria and underwent descriptive analyses.

RESULTS

LC-OCT revealed characteristic features of cicatricial alopecia, such as lymphocytic interface dermatitis (14/15; 93.3%) and basal cell vacuolization (13/15; 86.7%). The most impressive feature was the occurrence of prominent hyperreflective fibers in 14/15 patients (93.3%).

CONCLUSION

LC-OCT imaging can noninvasively detect morphologic criteria such as lymphocytic and vacuolar interface dermatitis of cicatricial alopecia due to LE. In particular, the presence of hyperreflective collagen fibers appears to be a characteristic easily recognizable feature that may facilitate differential diagnosis with other forms of cicatricial alopecia. Further studies are mandatory to differentiate other forms of scarring alopecia.

Reflectance confocal microscopy as a complementary diagnostic tool for greyish-brown dermatoses in children

Mastocytosis, lichen planus pigmentosus (LPP), fixed drug eruption (FDE) and café-au-lait macules (CALM) have a similar appearance, often lead to misdiagnosis and missed diagnoses. At the outpatient clinic at Tianjin Children's Hospital in 21 patients with mastocytosis, 18 with LPP, 11 with FDE and 12 with CALM we evaluated the characteristics and distinguishing features of their dermatoses using reflectance confocal microscopy (RCM). In mastocytosis, the dermal papillary rings generally had a significantly increased bright refractive index and the superficial dermis was filled with moderate refractive flocculent material. In LPP, the dermal papillary rings were absent and numerous different-sized cellular structures were densely distributed in the superficial dermis. In FDE, the dermal papillary rings were intact with a significantly increased bright refractive index. In CALM, normal dermal papillary rings were detected with a uniformly slightly increased refractive index and no obvious abnormality in the superficial dermis. RCM allows for real-time visualization of the major key diagnostic and distinguishing features of four greyish-brown dermatoses in children.

Dermoscopy for the Differentiation of Subacute Cutaneous Lupus Erythematosus from Other Erythematous Desquamative Dermatoses-Psoriasis, Nummular Eczema, Mycosis Fungoides and Pityriasis Rosea

Subacute cutaneous lupus erythematosus (SCLE) is a condition that might pose a diagnostic challenge. The aim of this study was to assess the usefulness of videodermoscopy in the differentiation of SCLE from other erythematous-desquamative dermatoses. Consecutive patients with SCLE (n = 27), psoriasis (n = 36), nummular eczema (n = 30), mycosis fungoides (n = 26), and pityriasis rosea (n = 20) referred to our Department of Dermatology were recruited for this study. A representative lesion was visualized using a Canfield D200EVO Videodermatoscope (Canfield Scientific GmbH, Bielefeld, Germany) and evaluated for the following parameters: vessels (morphology and distribution), scales (color and distribution), follicular findings, colors and morphologies, and presence of specific clues. SCLE was predominantly characterized by a polymorphous vascular pattern (92.6%) of unspecific distribution (92.6%) over a pink-red background (74.1%). Gray-brown dots were present in 10 (37.0%) cases, and pigmentation was noted in 15 (55.6%) patients, including peripheral pigmentation in 7 (25.9%) patients. Videodermoscopic evaluation showed significant differences between SCLE and psoriasis, which was characterized by regularly distributed dotted vessels. Although some common dermoscopic features with MF were noted, the presence of yellow structureless areas and red dots/globules favored the diagnosis of MF. In conclusion, a polymorphic vascular pattern, especially in association with gray-brown dots and/or peripheral pigmentation, is a valuable clue for the differentiation of SCLE from other erythematous-desquamative dermatoses.

Preliminary evaluation of penile papule dermatoses with reflectance confocal microscopy in children

BACKGROUND

Owing to their similar appearance, lichen striatus (LS), lichen nitidus (LN), juvenile xanthogranuloma (JXG), and molluscum contagiosum (MC) on the penis often lead to misdiagnosis and missed diagnosis, especially in children. In vivo evaluation of penile dermatoses with reflectance confocal microscopy (RCM) is helpful in the diagnosis of these ambiguous lesions in children.

METHODS

We recruited 12 patients with LS, nine with LN, seven with JXG, and nine with MC and evaluated the characteristics and distinguishing features of the four kinds of papule dermatoses on the penis using RCM.

RESULTS

The four dermatoses all had unique RCM features. LS generally showed focally destroyed dermal papillary rings, with numerous mononuclear cell clusters aggregated inside the papillary rings, and highly refractive clumps were observed. For LN, the dermal papillary rings were completely destroyed and arranged in a solitary, enlarged, cavity-like structure, in which round cells, particulate matter structures, and plump cellular structures were aggregated; the adjacent skin was completely normal. In JXG, the dermal papillary rings were significantly dilated, and the superficial dermis was filled with different-sized large bright ring cells; smaller, refractive, roundish structures; and particulate matter. For MC, the normal structures completely disappeared; the lesions were arranged in a crater-shaped structure; and a mass-like substance formed by the aggregation of multiple, uniform, roundish structures was observed within the crater.

CONCLUSION

RCM allows for real-time visualization of major key diagnostic and distinguishing features of four papule dermatoses, LS, LN, JXG, and MC, on the penis in children.

Dermoscopic Features of Acute, Subacute, Chronic and Intermittent Subtypes of Cutaneous Lupus Erythematosus in Caucasians

Cutaneous lupus erythematosus (CLE) is divided into the following four clinical subtypes: acute CLE (ACLE), subacute (SCLE), chronic CLE (CCLE) and lupus erythematosus tumidus (LET). The aim of this study was to describe the dermoscopic patterns of CLE by clinical variant. A total of 54 Caucasian patients from Poland (ACLE = 10; SCLE = 11; CCLE = 26; LET = 7) were included. The predefined parameters for dermoscopic assessment in inflammatory dermatoses were analyzed separately by two dermatologists. Under dermoscopy, all the variants of CLE showed predominantly polymorphous vessels on a pink−red background within the lesional skin. Dotted vessels, in association with other vessel morphologies, were observed more frequently in SCLE than in the other subtypes of CLE, but the difference did not reach statistical significance (p = 0.07). The findings associated with hair follicles, including rosettes (p = 0.02), follicular plugs (p = 0.01), follicular red dots (p < 0.01), perifollicular white halos (p < 0.01) and dermoscopic features corresponding to scarring, including white (p = 0.01) and pink (p < 0.01) structureless areas, were significantly more common in CCLE than in other variants of CLE. A lack of scaling, pigmentation, erosions and crusting were observed in all the cases of LET. The role of dermoscopy as an auxiliary tool in the differential diagnosis of CLE needs further elucidation.

Horizontal Histopathology Correlation with In Vivo Reflectance Confocal Microscopy in Inflammatory Skin Diseases: A Review

Horizontal histopathological sections (HHSs) have been reported to show a strong correlation with images obtained via in vivo reflectance confocal microscopy (RCM), as both reflect the same horizontal plane of the skin. Although vertical histopathology remains the diagnostic gold standard for most neoplastic and inflammatory skin diseases, HHSs represent a useful tool to validate the RCM features of some inflammatory disorders, including psoriasis, discoid lupus erythematosus, and eczema. The aim of the present review is to summarize the state of the art on the existing correlations between HHS and RCM in this field and to emphasize that RCM may represent a useful diagnostic tool to discriminate between diseases with similar clinical presentations.

Machine Learning Based Prediction of Squamous Cell Carcinoma in Ex Vivo Confocal Laser Scanning Microscopy

Image classification with convolutional neural networks (CNN) offers an unprecedented opportunity to medical imaging. Regulatory agencies in the USA and Europe have already cleared numerous deep learning/machine learning based medical devices and algorithms. While the field of radiology is on the forefront of artificial intelligence (AI) revolution, conventional pathology, which commonly relies on examination of tissue samples on a glass slide, is falling behind in leveraging this technology. On the other hand, ex vivo confocal laser scanning microscopy (ex vivo CLSM), owing to its digital workflow features, has a high potential to benefit from integrating AI tools into the assessment and decision-making process. Aim of this work was to explore a preliminary application of CNN in digitally stained ex vivo CLSM images of cutaneous squamous cell carcinoma (cSCC) for automated detection of tumor tissue. Thirty-four freshly excised tissue samples were prospectively collected and examined immediately after resection. After the histologically confirmed ex vivo CLSM diagnosis, the tumor tissue was annotated for segmentation by experts, in order to train the MobileNet CNN. The model was then trained and evaluated using cross validation. The overall sensitivity and specificity of the deep neural network for detecting cSCC and tumor free areas on ex vivo CLSM slides compared to expert evaluation were 0.76 and 0.91, respectively. The area under the ROC curve was equal to 0.90 and the area under the precision-recall curve was 0.85. The results demonstrate a high potential of deep learning models to detect cSCC regions on digitally stained ex vivo CLSM slides and to distinguish them from tumor-free skin.