High-frequency ultrasound for differentiation between high-risk basal cell carcinoma and cutaneous squamous cell carcinoma.

BACKGROUND: The similar visual appearance of high-risk basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) may cause confusion for diagnosis. High-frequency ultrasound (HFUS) may provide additional intralesional information and thus help to distinguish them. METHOD: In this retrospective study, we analyzed the clinical characteristics, HFUS grayscale, and color Doppler flow imaging (CDFI) features of pathologically confirmed high-risk BCC and cSCC lesions (n = 65 vs n = 68). Subsequently, discrimination models based on the significant HFUS features were established. RESULTS: Between high-risk BCC and cSCC lesions, the HFUS grayscale features of the lesion size (10.0 mm vs 17.4 mm), thickness (3.1 mm vs 5.9 mm), internal hyperechoic spots (80.0% vs 23.5%), and posterior acoustic shadowing (16.9% vs 66.2%) were statistically different (all p < 0.001). As for the CDFI features, high-risk BCC lesions mainly appeared as pattern II (47.7%), while cSCC lesions mainly appeared as pattern III (66.2%). Based on the above five features, an optimal discrimination model was established with a sensitivity of 91.2%, a specificity of 87.7%, and an accuracy of 89.5%. CONCLUSION: HFUS features, including size, thickness, internal hyperechoic spots, posterior acoustic shadowing, and Doppler vascularity pattern, are useful for differential diagnosis between high-risk BCC and cSCC.

Ultrasound Biomicroscopy and High-Frequency Ultrasound for Evaluating Extramammary Paget Disease With Pathologic Correlation.

OBJECTIVES: The purpose of this study was to investigate the performance of ultrasound biomicroscopy (UBM) and high-frequency ultrasound (HFUS) in the assessment of extramammary Paget disease (EMPD) and to correlate the imaging features with pathologic findings. METHODS: In this retrospective study, we described the imaging features from UBM and HFUS based on 17 pathologically proven EMPD cases. The performance for visualizing layer involvement by UBM and HFUS was compared. Additionally, we checked the consistency between layer involvement of the lesions on UBM images and the pathologic results. Additionally, blood flow and the status of lymph nodes were investigated with HFUS. RESULTS: Ultrasound biomicroscopy revealed that all 17 lesions (100%) were hypoechoic and grew in a creeping form. The feature of layer involvement was shown in 10 lesions (58.8%) limited to the epidermis and 6 lesions (35.3%) involving the dermis, and the remaining lesion (5.9%) involved the full skin layers. Layer involvement was clearly displayed by UBM for all lesions (100%) but for only 5 lesions (29.4%) by HFUS (P < .001). Additionally, the layer involvement of 15 lesions (88.2%) on UBM was consistent with the pathologic results (κ = 0.746). High-frequency ultrasound revealed profuse blood flow in most lesions (64.7% [11 of 17]), and 1 case showed inguinal lymph node metastasis. CONCLUSIONS: Combined use of UBM and HFUS can provide key information on EMPD based on ultrasound features. Comparatively, UBM provides clearer morphologic information, whereas HFUS provides information on lymph node metastasis and blood flow.

Is Human Sebum the Source of Skin Follicular Ultraviolet-Induced Red Fluorescence? A Cellular to Histological Study.

BACKGROUND: The ultraviolet-induced red fluorescence (UVRF) from human skin follicles was suggested to be a result of Propionibacterium acnes and was used for the monitoring of acne. More recent studies suggested that the UVRF may be more related to sebum rather than to microorganisms. OBJECTIVE: To clarify whether human sebum or follicular microorganisms are the source of UVRF. METHODS: We examined the fluorescence of human-derived SZ95 sebocytes, human sebaceous glands, sebum extracted from the sebaceous glands, and bacteria isolated from human hair follicles under ultraviolet light. RESULTS: SZ95 sebocytes, human sebaceous glands, and sebum do not emit UVRF. Two types of UVRF peaking at about 635 nm and at about 620 nm were detected in P. acnes and Staphylococcus epidermidis, respectively. This is the first report that S. epidermidis emits UVRF when it is anaerobically cultured and then exposed to air. CONCLUSION: Human follicular UVRF is emitted by resident bacteria, not by sebum. Therefore, UVRF may be used to monitor certain species of skin microorganisms.

Quantifying facial skin erythema more precisely by analyzing color channels of The VISIA Red images.

BACKGROUND: The VISIA Red images were developed to document and measure facial skin erythema, but diffuse erythema cannot be fully segmented by the VISIA system due to the automatic thresholding segmentation method. Moreover, topical area analysis is not available in the system. MATERIALS AND METHODS: Erythema severity degrees of 20 simulated Red images were designated 1-20 with 1-20 inflammatory lesions for each, respectively. The RGB channel mean values of each simulated image were acquired by ImageJ and relative intensity of red values calculated. RESULTS: The relative intensity of red values positively correlate to erythema severity with a coefficient of 0.999345 (p < 0.001). We also proposed a method for calibration when pustules were present in the erythema area. The method was proved by mathematical reasoning and verified by certified dermatologists. CONCLUSION: We demonstrated a simple and more precise method to quantify and compare facial skin erythema by analyzing the RGB channel values of the VISIA Red images. Our method brings convenience for erythema evaluation in dermatological studies.

Value of High-Frequency Ultrasound for Differentiating Invasive Basal Cell Carcinoma from Non-invasive Types.

The purpose of the study was to evaluate the value of high-frequency ultrasound (HFUS) for differentiating invasive basal cell carcinomas (BCCs) from non-invasive BCCs. We established a prediction model based on ultrasound features and validated it further. One hundred patients in the pilot cohort and another 43 in the validation cohort were evaluated. All patients underwent HFUS examinations by the same radiologist, and then were divided on the basis of pathology into invasive and non-invasive types. With respect to growth pattern, 60.5% of invasive BCCs had an irregular pattern, whereas 89.5% of non-invasive BCCs had a nodular or crawling pattern (p < 0.001). As for the layers involved, the more invasive BCCs broke through the dermis compared with non-invasive BCCs (23.3% vs. 1.8%) (p < 0.001). With respect to intralesional hyperechoic spot distribution, invasive and non-invasive BCCs tended to be clustered and absent/scattered-like, respectively (55.8% vs. 91.2%) (p < 0.001). On the basis of the aforementioned features, a prediction model was established with accuracies of 84.0% and 76.7%, respectively, in the pilot and validation cohorts. HFUS holds promise for the differentiation of the invasiveness of BCCs and is helpful in its clinical management.