Concordance of in vivo reflectance confocal microscopy and horizontal-sectioning histology in skin tumours.

BACKGROUND: In vivo reflectance confocal microscopy (RCM) enables the study of architectural and cytological aspects in horizontal sections, which closely correlate with histologic features. However, traditional histopathological vertical sections cannot totally reproduce the image of the in vivo RCM horizontal section. OBJECTIVE: To evaluate the concordance between in vivo RCM and histopathologic transverse sections for melanocytic lesions, basal cell carcinoma and seborrheic keratoses. METHODS: Prospectively collected benign melanocytic and non-melanocytic tumours diagnosed by dermoscopy were evaluated for common RCM features and compared to histopathology in horizontal sections with haematoxylin and eosin staining. RESULTS: A total of 44 skin tumours including 19 melanocytic lesions (nine compound, five junctional and five intradermal nevi), 12 basal cell carcinomas and 13 seborrheic keratoses were collected in the Department of Dermatology of Hospital Clinic of Barcelona. The RCM features that had statistically significant agreement with the histopathological horizontal sections were the preserved and visible honeycomb pattern, well defined DEJ, small bright particles, dermal nests, tumour islands and dark silhouettes, clefting, collagen bundles, thickened collagen bundles and cytologic atypia. CONCLUSIONS: Histopathology evaluation of horizontal sections of skin tumours can be correlated with main RCM findings. The results of this study have improved the understanding and interpretation of RCM features in relation to skin tumours, thus reinforcing the utility of RCM as a diagnostic tool.

Diagnostic accuracy of dermoscopy for 934 basal cell carcinomas: A single-center retrospective study.

Although the efficacy of dermoscopic diagnosis of basal cell carcinoma (BCC) has already been established, most studies have been conducted in Western countries. However, there are racial differences in the clinicopathological characteristics of BCC, highlighting the need for a survey among Asians. Herein, we aimed to investigate the diagnostic accuracy of dermoscopy in 934 Japanese patients with BCC and statistically analyze the clinicopathological factors affecting diagnostic accuracy. We analyzed 5093 skin lesions, including 934 BCCs that were diagnosed consecutively from 1998 to 2018. The sensitivity and specificity of dermoscopic diagnosis for BCC were calculated. The sensitivity and specificity of dermoscopic diagnosis were 92.2% and 96.0%, respectively. There were 73 false-negative cases of BCCs that were clinically diagnosed with other diseases. The most common incorrect clinical diagnosis was seborrheic keratosis (n = 18), followed by melanocytic nevus (n = 15). Multiple logistic regression analysis showed that sensitivity was significantly lower in BCCs located on the trunk and extremities, which showed low pigmentation (less than 10% of the lesion surface) and were diagnosed by a resident dermatologist. Experience of 3-6 months of 12 resident dermatologists revealed increased sensitivity. Dermoscopy is a reliable tool for the accurate diagnosis of BCC in Japanese individuals. Care should be taken when diagnosing BCCs of the trunk and extremities, and the less-pigmented subtype because of lower sensitivity. A certain amount of experience is required to improve the skills for dermoscopy.

Real-time high-resolution millimeter-wave imaging for in-vivo skin cancer diagnosis.

High-resolution millimeter-wave imaging (HR-MMWI), with its high discrimination contrast and sufficient penetration depth, can potentially provide affordable tissue diagnostic information noninvasively. In this study, we evaluate the application of a real-time system of HR-MMWI for in-vivo skin cancer diagnosis. 136 benign and malignant skin lesions from 71 patients, including melanoma, basal cell carcinoma, squamous cell carcinoma, actinic keratosis, melanocytic nevi, angiokeratoma, dermatofibroma, solar lentigo, and seborrheic keratosis were measured. Lesions were classified using a 3-D principal component analysis followed by five classifiers including linear discriminant analysis (LDA), K-nearest neighbor (KNN) with different K-values, linear and Gaussian support vector machine (LSVM and GSVM) with different margin factors, and multilayer perception (MLP). Our results suggested that the best classification was achieved by using five PCA components followed by MLP with 97% sensitivity and 98% specificity. Our findings establish that real-time millimeter-wave imaging can be used to distinguish malignant tissues from benign skin lesions with high diagnostic accuracy comparable with clinical examination and other methods.

Dynamic thermal imaging for pigmented basal cell carcinoma and seborrheic keratosis.

BACKGROUND: Clinical differentiation between pigmented basal cell carcinoma (BCC) and seborrheic keratosis (SK) can sometimes be difficult. Noninvasive diagnostic technologies, such as thermal imaging, can be helpful in these situations. This study explored the use of dynamic thermal imaging (DTI), which records thermal images after the application of external thermal stimuli (heat or cold) for the differential diagnosis of pigmented BCC and SK. MATERIALS AND METHODS: Twenty-two patients with pigmented BCC and 15 patients with SK participated in this study. Dynamic thermal images of lesions (pigmented BCC or SK) and control sites (contralateral normal skin) were recorded after the heat and cold stimuli. Temperature changes in the region of interest (ROI) are plotted as a thermal response graph. After fitting an exponential equation to each thermal response graph, the rate constants were compared between groups (pigmented BCC versus control, SK versus control). RESULTS: The thermal response graphs revealed that the average temperature of pigmented BCC showed faster thermal recovery to baseline than the control site. There was a significant difference in the rate constants of the fitted exponential equations between the pigmented BCCs and the control sites (p<.001). However, we did not find a significantly different thermal recovery pattern between SK lesions and control sites. CONCLUSIONS: DTI can be used as a diagnostic tool for distinguishing pigmented BCC from SK by comparing thermal recovery patterns between target lesions (pigmented BCC or SK) and the control site.

In vivo two-photon-excited cellular fluorescence of melanin, NAD(P)H, and keratin enables an accurate differential diagnosis of seborrheic keratosis and pigmented cutaneous melanoma.

SIGNIFICANCE: Seborrheic keratoses (SKs) are harmless pigmented skin lesions (PSLs) that may be confused clinically not only with other benign conditions but also with cutaneous melanoma (CM). As SKs are one of the most common neoplasms in adults, the importance of their correct diagnosis is high. Misclassifying SK as malignant is not rare and leads to a high number of unnecessary biopsies. On the other hand, misdiagnosing CM as SK may have a large impact on prognosis or therapy. AIM: In the non-invasive technique of dermatofluoroscopy, the fluorophores in melanocytes and keratinocytes are excited in vivo with nanosecond laser pulses and the resulting spectrally resolved, melanin-dominated fluorescence signals are used to differentiate between pigmented benign lesions and CM. APPROACH: In this single-center, non-interventional study, 33 PSLs of 20 patients were scanned with dermatofluoroscopy in vivo. For all included cases, dermatofluoroscopic signals were compared to pathology classification. RESULTS: The characteristic spectral features of SK were identified, where the signals are dominated by keratin, NAD(P)H, and melanin. The fluorescence spectra of SKs differed substantially from those of CM: a characteristic spectrum of SK has been identified in 27 of 28 SKs. CONCLUSIONS: The high-accuracy differential diagnosis between CM and SK is possible with dermatofluoroscopy.

Dermoscopic findings of genital keratotic lesions: Bowenoid papulosis, seborrheic keratosis, and condyloma acuminatum.

Dermatologists often encounter keratotic or warty lesions in the genital area. Establishing a clear diagnosis may seem challenging, particularly when the differential diagnosis includes bowenoid papulosis, seborrheic keratosis, and condyloma acuminatum. This study aimed to compare the dermoscopic features of bowenoid papulosis (BP), seborrheic keratosis, and condyloma acuminatum in the genital area. All lesions histopathologically confirmed underwent clinical assessment and dermoscopic observation. Dermoscopically, glomerular vessels were predominant in bowenoid papulosis, whereas seborrheic keratosis was the least vascular-patterned disease. Most cases of bowenoid papulosis presented mucosal pigmentation and classified as "flat". Seborrheic keratosis had a pigmented, cerebriform appearance. Condyloma acuminatum was characterised by a finger-like appearance, highly vascular-patterned features surrounded by whitish halos. Dermoscopic findings can be useful for differentiating the entity of genital keratotic lesions ahead of an invasive method. When dermoscopic features favor BP, different from genital warts, it should be removed completely but conservatively.

Dermatoscopy and Reflective Confocal Microscopy for Facial Seborrheic Keratosis, Verruca Plana, and Nevus Pigmentosus.

OBJECTIVE: To describe the features of facial seborrheic keratosis, verruca plana, and nevus pigmentosus by dermatoscopy and reflective confocal microscope (RCM). STUDY DESIGN: Cross-sectional observational study. PLACE AND DURATION OF STUDY: Dermatology Department of The Affiliated Hospital of Xuzhou Medical University from January 2017 to January 2019. METHODOLOGY: Patients of either gender and age, clinically diagnosed as seborrheic keratosis, verruca plana, and nevus pigmentosus without any prior treatment, were enrolled. Patients with extremities and trunk involvement were excluded. One typical skin lesion was chosen from each patient and subjected to dermatoscopy and RCM separately; imaging features were recorded and analysed. RESULTS: A total of 402 patients (183 men and 219 women) between 6 and 88 years of age (mean age 41.8 years) were inducted. The duration of disease was between one week and 10 years. Seborrheic keratosis on dermatoscopy presented as acne-like openings (122/172; 70.93%, milia-like cysts (113/172; 65.70%), hairpin-like vessels (108/172; 62.79%, brain-like structures (103/172; 59.88%, worm-like pharyngeal margins (17/172; 9.88%), and fingerprint-like structures (8/172; 4.65%). On RCM, it showed epidermal cerebral gyrus structure (165/172; 95.93%), superficial vasodilatation and hyperemia (81/172; 47.09%), and keratinous cysts (73/172; 42.44%). Verruca plana on dermatoscopy showed a number of punctate hemorrhages scattered against a light-red background (108/114; 94.74%); on RCM it showed rose-like concentric structures (89/114; 78.07%). The features of nevus pigmentosus observed by dermatoscopy were homogeneous mode (23/52; 44.23%), light brown color (30/52; 57.69%) for intradermal nevus; mesh mode (18/41; 43.90%, dark brown color, little black dots and spherical structure (both 18/41; 43.90%) were visible for junctional nevus; globular mode, reticular and cobblestone structures (both 11/23; 47.83%) for compound nevus. On RCM, there were a few nevus cells visible within the dermal papilla (52/52; 100%) for intradermal nevus; bright pebble-like structures accumulated in the basal layer, nested round and elliptical nevus cells (40/41; 97.56%) for junctional nevus; nevus cells in the epidermis and dermis (21/23; 91.30%) for compound nevus. CONCLUSION: Used in combination with clinical manifestations, the application of dermatoscopy and RCM may help distinguish seborrheic keratosis, verruca plana, and nevus pigmentosus on the basis of their respective dermatoscopic and RCM features. Key Words: Dermatoscopy, Reflective confocal microscope, Seborrheic keratosis, Verruca plana, Nevus pigmentosus, Brain-like structures, Rose-like structure.

Usefulness of high-frequency ultrasound in differentiating basal cell carcinoma from common benign pigmented skin tumors.

BACKGROUND: Basal cell carcinoma (BCC) is the most common cutaneous malignancy. Occasionally, it may have an appearance similar to that of some benign pigmented skin lesions. Therefore, additional information is needed to differentiate these lesions. MATERIALS AND METHODS: A diagnostic accuracy study was performed from February 2018 to April 2019. All lesions underwent ultrasound examination with 50 and 20 MHz probes. The high-frequency ultrasound (HFUS) images were evaluated independently by 2 experienced doctors for the presence of predefined features, including the depth, shape, margin, anechoic area, hyperechoic spots, epidermal interrupted echo, mushroom sign, flat-bottom sign, and superficial hyperechoic focus (SHEF). RESULTS: A total of 54 BCCs, 51 melanocytic nevi and 55 seborrheic keratoses (SK), were included. BCCs often involved the subcutaneous tissue (11/54, 20.4%; P < .001) and had an irregular shape (26/54, 48.1%; P < .001) and ill-defined borders (26/54, 48.1%; P < .001), while most benign pigmented lesions had a regular shape (101/106, 95.3%; P < .001) and well-defined borders (95/106, 89.6%; P < .001). BCCs occasionally showed anechoic areas (10/54, 18.5%; P < .001) and epidermal interrupted echo (18/54, 33.3%; P < .001). Moreover, hyperechoic spots could be found in BCCs (43/54, 79.6%), nevi (27/51, 52.9%), and SK (30, 54.5%) (P = .001), with mean number of 7.3, 5.5, and 8.0, respectively. The mushroom signs were all present in melanocytic nevi (18/51, 35.3%), while the flat-bottom sign (43/55, 78.2%; P < .001) and SHEF (40/55, 72.7%; P < .001) presented mainly in SKs. CONCLUSIONS: Based on the typical features, HFUS could improve the accuracy of BCC identification and should be considered when dermatologists are unsure about the lesion type.

Combining Reflective Confocal Microscopy and Dynamic Optical Coherence Tomography to Diagnose Melanoacanthoma: Case Report.

ABSTRACT: Few reported cases discuss distinguishing between melanoma and melanoacanthoma, a seborrheic keratosis (SK) variant, using noninvasive imaging devices. We present a case of a 38-year-old man with Fitzpatrick skin type IV with an asymmetric black papule showing clinical and dermoscopic features of both melanoma and SK. Reflectance confocal microscopy (RCM) and dynamic optical coherence tomography (d-OCT) were used for further evaluation. RCM revealed acanthotic epidermis with a mixed honeycomb and cobblestone pattern, polycyclic bulbous rete ridges, and bright plump cells within entrapped, edged, dermal papillae, compatible with pigmented SK. Also noted were a population of fairly uniform bright dendritic cells scattered quite evenly at all levels of the epidermis and the notable absence of concomitant features of a melanocytic neoplasm (roundish Pagetoid cells, sheets of roundish or dendritic cells at the dermal-epidermal junction, junctional thickenings, and melanocytic nests), suggesting melanoacanthoma. d-OCT showed well-circumscribed, regular, epidermal acanthosis, superficial rounded hypodense structures, normal vascular flow, and notable absence of wiry or contoured vessels, features typically seen in SKs and benign lesions, respectively. Similarly, histologic examination revealed characteristics of pigmented SK containing a population of evenly dispersed dendritic melanocytes (decorated using Melan-A stain) confirming a diagnosis of melanoacanthoma. This case highlights the advantages of incorporating both RCM and d-OCT into clinical practice to noninvasively differentiate melanoma from its clinical mimickers.

Accuracy of dermoscopic criteria for the differential diagnosis between irritated seborrheic keratosis and squamous cell carcinoma.

BACKGROUND: Even with the addition of dermoscopy, a significant morphologic overlap exists between irritated seborrheic keratosis (ISK) and squamous cell carcinoma (SCC). OBJECTIVE: The aim of this study was to investigate the dermoscopic criteria that could serve as potent predictors for the differential diagnosis between ISK and SCC. METHODS: Dermoscopic images of histopathologically diagnosed ISKs and SCCs were evaluated by 3 independent investigators for the presence of predefined criteria. RESULTS: A total of 104 SCCs and 61 ISKs were included. The main dermoscopic predictors of SCC were dotted vessels (odds ratio [OR], 10.4), branched linear vessels (OR, 5.30), white structureless areas (OR, 6.78), white circles surrounding follicles (OR, 23.45), a diffuse irregular (OR, 2.55) or peripheral (OR, 2.8) vessel arrangement, and a central scale arrangement (OR, 3.35). Dermoscopic predictors of ISK were hairpin vessels (OR, 0.38), a diffuse regular vessel arrangement (OR, 0.39 and OR, 0.36), and white halos surrounding vessels covering more than 10% of the lesion (OR, 0.29 and OR, 0.12). LIMITATIONS: First, the retrospective design of the study; second, the differential diagnosis included in the study was restricted to ISK and SCC. CONCLUSIONS: We confirmed the significant morphologic overlap between ISK and SCC, but we also identified potent predictors for the differential diagnosis between these 2 entities.

In vivo reflectance confocal microscopy for evaluating seborrheic keratosis, verruca plana, syringoma and lichen nitidus.

BACKGROUND: In clinical, common facial papule dermatosis such as seborrheic keratosis (SK), verruca plana (VP), syringoma and lichen nitidus (LN) is often misdiagnosed. Summarizing in vivo reflectance confocal microscopy (RCM) features of the facial papule dermatosis is helpful in the diagnosis of ambiguous lesions. The purpose of this study was to evaluate the features of SK, VP, syringoma, and LN in RCM. METHODS: We recruited 144 patients referred for unequivocal facial papule dermatosis including 60 patients with SK, 60 patients with VP, 10 patients with syringoma, and 14 patients with LN. The RCM images were evaluated at the epidermis, the dermoepidermal junction, and the dermis from both papule lesions and normal skin. RESULTS: In the epidermis, the cerebriform shape was the main RCM characteristic of SK and the "petal-like" structure was the main RCM characteristic of VP. In the dermoepidermal junction, the RCM features we found were as follows: For SK, the bright dermal papillary rings, the abnormal dermal papilla and the looped vessels were also observed at the abnormal dermal papilla. For VP, the bright dermal papillary rings and the point-like blood vessels were also observed at the round dermal papills. For LN, the round, enlarged, well-circumscribed dermal papillae and the enlarged dermal papillaes were heavily laden with individual highly refractive cells. In the dermis, RCM examination revealed brightly refractile teratogenous sweat tube, designing variably visible bright "moon" structures in all syringoma patients. CONCLUSION: Considering our results, RCM may be useful to non-invasively discriminate SK, VP, syringoma and LN in vivo.

Evaluation of ultrahigh-resolution optical coherence tomography for basal cell carcinoma, seborrheic keratosis, and nevus.

BACKGROUND: Basal cell carcinoma, seborrheic keratosis, and nevus are common skin conditions. Though most of the skin diseases can be distinguished from each other by physician's naked eyes, the diagnostic accuracy is not 100%. The accurate diagnosis and assessment of three diseases make a big difference on the clinical management. Nowadays, biopsy is still the gold standard for diagnosis even it is invasive, time-consuming, and painful. Ultrahigh-resolution optical coherence tomography is an emerging technology that can produce in situ, cellular-resolution, real-time, continuous, 3D images in a noninvasive way. MATERIALS AND METHODS: In our study, four basal cell carcinoma patients, five seborrheic keratosis patients, and 10 nevus patients who were diagnosed by histology were studied by ultrahigh-resolution optical coherence tomography after visual examination by experienced dermatologists. Cellular contrast was utilized to clearly identify the features of the three skin diseases. RESULTS: The features including such as hyperkeratosis (horn pseudocysts), papillomatosis, intraepidermal nests, elongated, and expanded rete ridge can be visualized in seborrheic keratosis. Tumor nodular, mucin surrounding with tumor (retraction space in histopathology), tumor subtype, and necrosis were featured in basal cell carcinoma. Pigment was characterized in epidermis and dermis. The comparison of ultrahigh-resolution optical coherence tomography images reveals a strong correlation with histological images. CONCLUSION: Ultrahigh-resolution optical coherence tomography can complement existing diagnostic techniques for investigating seborrheic keratosis, basal cell carcinoma and nevus, and show enormous potential in vivo applications for the three skin diseases in the future.

Benign pigmented skin lesions.

BACKGROUND: Benign pigmented skin lesions are extremely common. Such lesions are seen every day in general practice. OBJECTIVE: The objectives of this paper are to develop a framework that may be used to evaluate pigmented skin lesions and a strategy for dealing with pigmented lesions, outline the conditions that improve the diagnosis of pigmented lesions (eg good lighting, careful inspection and dermoscopy), and increase clinician confidence in identifying pigmented lesions with concerning features. DISCUSSION: Regular assessment of pigmented skin lesions during patient consultations, including in an opportunistic fashion, will increase diagnostic acumen and help to identify potentially problematic lesions, and may improve patient awareness of lesions on their skin.

Evaluation of dermoscopic criteria for seborrheic keratosis on non-polarized versus polarized dermoscopy.

BACKGROUND: The two dermoscopic methods, polarized dermoscopy (PD) and non-polarized dermoscopy (NPD), use different types of light sources. Here, we aimed to explore the differences between these two methods in the diagnosis of seborrheic keratosis (SK). MATERIALS AND METHODS: The images of 121 cases of SK taken by a digital camera equipped with NPD and PD were evaluated against 14 dermoscopic criteria of SK. RESULTS: The agreement levels between NPD and PD were fair to perfect against the dermoscopic criteria of SK. Perfect agreement was observed in fingerprint-like structures (κ = 0.812) and linear irregular vessels (κ = 0.807). Substantial agreement was determined in comedo-like openings (κ = 0.640), hairpin vessels (κ = 0.609), a moth-eaten border (κ = 0.642), sharp demarcation (κ = 0.637), network-like structures (κ = 0.662), and a mica-like pattern (κ = 0.639). Moderate agreement was found in milia-like cysts (κ = 0.550), fissures and ridges (κ = 0.554), dotted vessels (κ = 0.496), and color variability (κ = 0.438). Fair agreement was obtained only in comma vessels (κ = 0.340). CONCLUSION: Based on our results, we cannot recommend an absolute dermoscopic method for the diagnosis of SK; rather, we suggest that the methods are complementary.