Melanin accumulation in acanthotic seborrheic keratosis: Reduced proliferation and early differentiation of keratinocytes and increased number of melanocytes.

Seborrheic keratosis (SK) is a common benign tumour, often associated with hyperpigmentation. To investigate the mechanism of melanin accumulation in SK, we have conducted comprehensive gene expression and histological analyses. We obtained five pairs of skin samples, including non-lesional and SK samples, from the backs of three male Japanese participants aged 40-59 years. To examine melanocytes and keratinocytes in SK, three pairs of skin samples were separated by laser capture microdissection into the basal layer and the other layer in the epidermis. We performed a comprehensive gene expression analysis to identify differentially expressed genes between non-lesional and SK skin, followed by gene ontology and pathway analysis. We found abnormal morphogenesis and cell proliferation in the basal layer, along with increased immune response and impaired cell differentiation and metabolism in the other layer of SK. We focused on cell proliferation and differentiation, as these are directly associated with melanin accumulation. Immunohistochemical analyses of Ki67, keratin 10, and keratin 14 demonstrated the decreases in the proliferation and early differentiation of the epidermis. Contrarily, no significant changes were observed in terminal differentiation markers, filaggrin and loricrin. Although the number of melanocytes was higher in SK than in non-lesional skin, melanogenic activity showed no difference. These results indicated that melanin accumulation in SK is caused by delayed melanin excretion due to reduced turnover around the basal and spinous layers of the epidermis and melanin production due to an increased number of melanocytes. Our findings provide new insights for therapeutic approaches in SK.

Tumor of follicular infundibulum - reappraisal in a series of 28 patients with critical review of the literature.

BACKGROUND AND OBJECTIVES: Tumor of follicular infundibulum (TFI) has been described as a neoplasm - isolated and multiple - and in association with other lesions. Its histopathologic definition is controversial. PATIENTS AND METHODS: We present a histopathologically analyzed series of 28 patients with TFI features. This has been supplemented by a search in MEDLINE on the literature on this subject. The corresponding figures given in these articles have been discussed and analyzed. RESULTS: Patients comprised 16 women and twelve men. TFI features were seen in five patients with nevus sebaceous, two trichofolliculomas, one dilated pore Winer, eight viral warts, one dermatofibroma, six seborrheic keratoses, three actinic keratoses, one invasive squamous cell carcinoma, and one basal cell carcinoma in association with a squamous cell carcinoma/actinic keratosis. After study of the literature especially of solitary cases of TFI, we interpret such cases mostly as variants of seborrheic keratoses with variable degree of infundibular, isthmic and/or sebaceous differentiation with or without regression. CONCLUSIONS: We regard TFI as an epithelial growth pattern which may occur in hamartomatous, inflammatory, infectious, reactive, or neoplastic conditions, in most solitary forms likely best classified within the histopathological spectrum of seborrheic keratoses.

Umbilical seborrheic keratosis-like lesion developing after diode laser hair removal in an 18-year-old patient.

OBJECTIVE: to report a possibly novel complication of laser hair removal. CASE REPORT: a white-skinned 18-year-old patient discovered an umbilical, brown, and raised lesion while shaving before his second diode laser hair removal session. He sought consultation before his fourth laser session since the lesion further thickened and darkened. Dermoscopy showed no pigmented network, but a few comedo-like openings within an erythematous-light brown scaly and fissured papule, "moth-eaten" borders, and a central crust due to manipulation, suggesting the diagnosis of seborrheic keratosis. We noted that the laser fluence was increased on the umbilical region where hair seemed resistant to treatment. The patient denied a recent history of local sun tanning, sunburns, inflammation, drainage, or manipulation. The lesion cleared, with no short-term relapse, after one session of cryotherapy. CONCLUSION: the development of a seborrheic keratosis-like lesion on a densely haired non-sun-exposed umbilicus of a young patient, following pre-laser shaving and high-fluence hair removal diode laser sessions, could have implicated triggering irritation and/or keratinocyte stimulation by red light-engendered reactive oxygen species (ROS) in the skin with silent epidermal mosaicism.

Effectiveness and safety of topical calcipotriol in the treatment of flat seborrheic keratosis on the face.

Seborrheic keratosis is the most common slow-growing, benign epithelial tumour, usually appearing on sun-exposed areas. Treatment modalities for seborrheic keratosis may be uncomfortable and/or time-consuming. We present a case series of 12 patients with solitary seborrheic keratosis localized on the face treated with 0.005% calcipotriol ointment. The treatment lasted 3-8 months and resulted in complete regression of the lesions. Remission (follow-up period) lasted from 6 to 10 years. We conclude that topical calcipotriol may be a useful treatment option for seborrheic keratosis.

Update of pathophysiology and treatment options of seborrheic keratosis.

Seborrheic keratosis (SK) is a common, benign tumor that can occur on everybody site and can be conservatively managed. Cosmetic concerns, especially when a lesion involves the facial area, are the most common reason for excision. SK shows male gender preponderance and increasing age is an independent association with the condition. Even though more prevalent in the elderly, it has also been reported in younger age groups like adolescents and young adults. Precise pathogenesis is still obscure, but ultra-violet exposure represents a predisposing factor to SK by altering the biochemical concentration and expression of factors like Glutamine deaminases, endothelin, and stem cell factor. Moreover, the accumulation of amyloid-associated protein has also been postulated. Involvement of genitalia has been associated with human papillomavirus infection. Recently, Merkel cell polyomavirus nucleic acid was also detected in SK. Several oncogenic mutations involving FGFR-3 and FOXN1 have been identified. SKs are usually classified clinically and histologically. Dermatoscopy is a noninvasive alternative diagnostic technique widely used in differentiating SK from other benign and malignant tumors. In terms of treatment, topical agents, shave dissection, cryosurgery, electrodesiccation, laser application and curettage under local anesthesia are safe methods for eradication of SKs, mostly for cosmetic purposes. Though generally safe, the latter techniques may occasionally cause post-procedure depigmentation, scarring, and recurrence. Nanosecond-pulsed electric field technology is a promising new technique with fewer side-effects.

Dermoscopic Predictors of Benignity and Malignancy in Equivocal Lesions Predominated by Blue Color.

BACKGROUND: Blue color in dermoscopy can be seen in a wide range of benign and malignant lesions, melanocytic or not. Some blue-colored dermoscopic criteria have been associated with specific tumors, such as blue-white veil with melanoma and homogeneous blue with blue nevi. However, when blue color occupies a large part of the lesion's surface, the dermoscopic assessment might be particularly challenging. OBJECTIVE: To identify dermoscopic predictors associated with benignity and malignancy in tumors characterized by a predominant dermoscopic presence of blue color. METHODS: We retrospectively screened our institutional database for tumors exhibiting blue color in at least 50% of their surface with available histopathologic diagnosis. Lesions with blue color covering less than 50% of their extent and lesions not histopathologically assessed were excluded. The dermoscopic images were evaluated for the presence of predefined criteria, including the characteristics of the blue color, coexisting colors, and the vascular structures. RESULTS: Of 91 included tumors, 53 were benign (35 blue nevi, 10 angiomas, and 8 seborrheic keratoses) and 38 malignant (12 melanomas and 26 basal cell carcinomas). Our analysis revealed 3 potent dermoscopic predictors of benignity: extension of blue color in more than 75% of the surface, diffuse distribution of blue color, and absence of vessels, posing a 2.3-fold, 5.6-fold, and 6.7-fold increased probability of benignity, respectively. In contrast, asymmetric distribution of blue color, blue clods, coexistence of gray color and linear vessels were significantly predictive of malignancy, posing a 8.9-fold, 2.8-fold, 13.5-fold, and 10.4-fold increased probability, respectively. CONCLUSION: In predominantly blue tumors, the probability of malignancy is high when blue color is seen in clods or is asymmetrically distributed and when gray color or linear vessels coexist. In contrast, a diffuse distribution of blue color, its expansion in more than 75% of the surface, and the absence of vessels are highly suggestive of a benign tumor.

Advances in the Etiology, Detection, and Clinical Management of Seborrheic Keratoses.

Seborrheic keratoses (SKs) are ubiquitous, generally benign skin tumors that exhibit high clinical variability. While age is a known risk factor, the precise roles of UV exposure and immune abnormalities are currently unclear. The underlying mechanisms of this benign disorder are paradoxically driven by oncogenic mutations and may have profound implications for our understanding of the malignant state. Advances in molecular pathogenesis suggest that inhibition of Akt and APP, as well as existing treatments for skin cancer, may have therapeutic potential in SK. Dermoscopic criteria have also become increasingly important to the accurate detection of SK, and other noninvasive diagnostic methods, such as reflectance confocal microscopy and optical coherence tomography, are rapidly developing. Given their ability to mimic malignant tumors, SK cases are often used to train artificial intelligence-based algorithms in the computerized detection of skin disease. These technologies are becoming increasingly accurate and have the potential to significantly augment clinical practice. Current treatment options for SK cause discomfort and can lead to adverse post-treatment effects, especially in skin of color. In light of the discontinuation of ESKATA in late 2019, promising alternatives, such as nitric-zinc and trichloroacetic acid topicals, should be further developed. There is also a need for larger, head-to-head trials of emerging laser therapies to ensure that future treatment standards address diverse patient needs.

In vivo evaluation of facial papule dermatoses with reflectance confocal microscopy in children.

BACKGROUND: Molluscum contagiosum (MC), milia, keratosis pilaris (KP), verruca plana (VP), seborrheic keratosis (SK), and juvenile xanthogranuloma (JXG) are common papule dermatoses on the face of children that have a similar appearance. In vivo evaluation of facial papule dermatoses with reflectance confocal microscopy (RCM) is helpful in the diagnosis of these ambiguous lesions in children. The purpose of this study was to clarify the RCM characteristics of MC, milia, KP, VP, SK, and JXG and explore the clinical application value of RCM for these common facial papule dermatoses. METHODS: We recruited 113 patients referred for unequivocal facial papule dermatosis, including 21 patients with MC, 17 patients with milia, 19 patients with KP, 36 patients with VP, 8 patients with SK, and 12 patients with JXG. We evaluated the characteristics and distinguishing features of the six kinds of facial papule dermatoses using RCM. RESULTS: The main RCM features of the six dermatoses included a well-demarcated border of the lesion area. MC, milia and KP all manifested cyst-like structures, and their distinguishing features were the location of the cystic structures and the refractive index of the contents. Although VP, SK, and JXG did not have obvious cystoid structures, VP was typically characterized by uniformly distributed petal-like structures with a medium-to-high refractive index in the epidermis. With regard to SK, the characteristic features were an obviously thickened epidermis and cobblestone-like structures. JXG was mainly characterized by multiple large round and ovoid cells with a foamy cytoplasm, and discoid-shaped multinucleated large cells were diffusely distributed in the dermis. CONCLUSION: RCM allows the real-time visualization of major key diagnostic and distinguishing features of common facial papule dermatoses in children, including MC, milia, KP, VP, SK, and JXG.

Human papillomavirus genotype distribution of genital keratotic lesions.

Genital keratotic lesions include bowenoid papulosis (BP), which histologically resembles squamous cell carcinoma in situ containing high-risk HPV, condyloma acuminatum (CA) that is a genital wart containing mostly low-risk HPV, and genital seborrheic keratosis (GSK), which is a benign epidermal tumour lacking a clear etiologic relationship with HPV. This study compared HPV genotype distributions among BP, CA and GSK and revealed that BP and GSK were related to high-risk HPV whereas CA was related to low-risk HPV. It is plausible that GSK is a distinct epidermal tumour often related to high-risk HPV rather than merely a senescent form of CA considering the overall discrepancy in the frequency distribution of HPV genotypes along with histopathological differences, and the detection of high-risk HPV in GSK alerts physicians to consider more active treatment and continued follow-ups.

Dermoscopy of inflamed seborrheic keratosis: A great mimic of malignancy.

BACKGROUND: Clinical and dermoscopic recognition of seborrheic keratoses (SKs) is often straightforward, and biopsy might not be required. However, inflamed SKs (iSKs) can pose a diagnostic challenge. Dermoscopic features of iSKs have not yet been evaluated to date. OBJECTIVES: To assess the diagnostic ability of a group of dermatologists to diagnose iSKs by dermoscopy. To evaluate the dermoscopic findings of a long series of inflamed seborrheic keratoses. METHODS: Clinical and dermoscopic images of 100 difficult-to-diagnose skin tumours, including 29 iSKs, were presented to 33 clinicians (24 dermatologists and 9 dermatology residents), who were blinded to the diagnosis. The dermoscopic features of a series of 219 iSKs were retrospectively analysed. RESULTS: iSKs were correctly identified in a 37.6% of cases. Classic dermoscopic criteria were present in only 47% of iSKs. The most frequent dermoscopic feature in iSKs was the presence of vascularization (91.3%), but only a 44.5% showed predominance of hairpin vessels. A bluish hue was observed in 18.3% of lesions. Seven dermoscopic patterns were identified, based on the dermoscopic similarity to other tumours: seborrheic keratosis-like (28.8%); squamous cell carcinoma-like (25.6%); melanoma-like (17.8%); keratoacanthoma-like (6.8%); basal cell carcinoma-like (5.9%); verruca vulgaris-like (5.9%); nevus-like (2.3%). CONCLUSIONS: The diagnosis of iSKs can be challenging even with dermoscopy. They may behave as authentic mimics of other cutaneous tumours, including squamous cell carcinoma or melanoma. For this reason, histopathological examination should be mandatory in these cases.

[The most common benign cutaneous neoplasms of the epidermis and appendages and their treatment]. / Häufigste gutartige Hauttumoren der Epidermis, ihrer Adnexe und deren Behandlung.

Benign cutaneous neoplasms are well defined histologically with absence of all of the following features: architectural disorder, necrosis, cytologic atypia, and atypical mitotic figures. The clinical appearance of any neoplasm is a very important diagnostic factor. The classification of the lesion determines the therapeutic options. This article summarizes the clinical aspects and treatments of the most common benign tumors of the epidermis and its appendages.

Melanocytes as the source of the increased melanisation in pigmented epithelial tumours: a holistic approach.

BACKGROUND: We aimed to elucidate the causes of the increased melanisation in basal cell carcinoma (BCC) and seborrheic keratosis (SK), and the role of melanocytes in this process. METHODS: This study was a retrospective-cohort study conducted in the pathology department of a university hospital between January 2019 and October 2020. Forty-nine SK and 30 pigmented BCC were included in our study. SRY-box transcription factor 10 (SOX10), CD68, and Masson-Fontana staining was used for analysis in all samples. A representative section of each specimen was photographed under ×400 magnification to facilitate the assessments of the morphology of the melanocytes and their following morphometric parameters: density, nuclear diameter, and distribution. The density of pigmented keratinocytes in the lesional epidermis was scored. The nuclear diameters of melanocytes located in the nonlesional epidermis, the density of the melanophages, and the presence or absence of ulceration and solar elastosis were also recorded. RESULTS: The morphometric findings confirmed a statistically significant increase in melanocyte density in the BCC group compared with that in the SK group (p < 0.001). Moreover, the nuclear minor diameters in the melanocytes of the BCC sections were significantly higher than those in the SK specimens (p < 0.001). The epidermal melanocytes were distributed diffusely in almost all BCC specimens (96.7%), whereas they were mainly limited to the basal layer in the majority of the SK sections (59.2%). The number of epidermal melanised keratinocytes with a score of 3 was significantly higher in the SK group (n = 31; 63.2%) than in the BCC group (n = 6; 20%) (p = 0.001), and they were the main cells representing the pigmented appearance of the tumours. No significant difference was found between both tumour groups in terms of their melanophage density scores (p = 0.206). DISCUSSION: This study is the first step towards an objective quantification of the melanocytes in pigmented epithelial tumours and may provide a morphological background for future studies on these skin lesions.

SEBORRHEIC KERATOSIS: CURRENT STATE OF THE PROBLEM.

OBJECTIVE: The aim is to identify age, gender, clinical and morphological features of seborrheic keratosis. PATIENTS AND METHODS: Material and methods: The study used biopsy material from 196 patients with a clinical diagnosis of "Seborrheic keratosis". In all cases, when studying directions for pathohistological examination, the authors analyzed gender and age characteristics, as well as localization of seborrheic keratosis. The resulting material was fixed in a 10% solution of neutral formalin (ph 7.4) for 24-48 hours. The procedure was carried out according to the generally accepted technique and the material was embedded in paraffin. Sections of 4-5×10-6m thick were made from paraffin blocks for staining with hematoxylin and eosin. The microspecimens were examined using an Olympus BX-41 microscope (Japan). RESULTS: Results: The study revealed a modern feature of seborrheic keratosis -"rejuvenation" of this tumor, as evidenced by its predominant development in patients aged 31 to 50 years. Seborrheic keratosis is more common in men, and is localized mainly on the skin of the face, scalp, neck and back. When diagnosing seborrheic keratosis, the author notes a significant discrepancy between clinical and morphological diagnoses, which actualizes the problem of improving the available clinical research methods and emphasizes the importance of morphological research. Hyperkeratotic and acanthotic histological variants of seborrheic keratosis are the most common. The case of seborrheic keratosis with malignancy and transformation into squamous cell carcinoma, identified by the author, should develop oncological alertness in doctors and patients. CONCLUSION: Conclusions: The study revealed age, gender, clinical and morphological features of seborrheic keratosis, which will contribute to a better understanding of this pathology by the doctors of various specialties, and improve the treatment and diagnostic process.

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.

Efficacy and safety of cryotherapy, electrodesiccation, CO2 laser, and Er:YAG laser in the treatment of seborrheic keratosis.

Seborrheic keratosis (SK) is a common benign skin epidermal lesion. Different treatment modalities have been proposed for this lesion. This study aimed to compare the efficacy and safety of electrodesiccation, cryotherapy, CO2 laser, and Er:YAG laser in the treatment of SK. The study was carried out on 30 patients each with four similar facial SKs. Each lesion was assigned to be treated with cryotherapy, electrodesiccation, CO2 laser, and Er:YAG laser in a random fashion. Therapeutic results were evaluated 8 weeks after the interventions through clinical and dermatoscopic assessment. Treatment improvement criteria for each lesion included the texture of the lesion, severity of the pigmentation, and an overall assessment of the healing. The severity of burning, pain, erythema, and the duration of the erythema after the procedures were documented. A survey of the patients' satisfaction with the treatments was also performed. In the assessment of overall lesion healing by two dermatologists, the improvement rate was significantly higher in the CO2, Er:YAG lasers and electrodesiccation group compared to the cryotherapy (p < 0.001). However, the CO2 and Er:YAG laser and the electrodesiccation groups showed no significant difference (p > 0.05). Moreover, no significant difference was observed in posttreatment pigmentation and texture between the groups (p > 0.05). The pain and burning severity after the interventions were negligible in all four groups. Prolonged erythema was not observed in any of the cases; however, the duration of erythema in the Er:YAG laser group was significantly longer (p < 0.001). Patient satisfaction in the cryotherapy group was significantly lower than the other three groups (p < 0.001). The efficacy of treatment and patient satisfaction rate is highly comparable between electrodesiccation, CO2 laser, and Er:YAG laser but significantly higher than cryotherapy.

Molecular detection and genotyping of ß-human papillomavirus and it's association with epithelial skin neoplasms.

Epidemiological and molecular biological data suggest that ß-human papillomavirus (HPV) can cause epithelial skin tumors, but the relationship remains unclear. A new approach to the diagnosis of HPV is based on the measurement of viral consistence. We examined 52 immune-compromised and immune-competent patients in order to identify the association of epithelial neoplasms with ß-HPV. Determination of HPV was performed by polymerase chain reaction with hybridization-fluorescence detection in real-time. Amplification and detection were carried out with "Rotor-Gene" 3000 ("Corbett Research," Australia). To quantify the beta HPV genus, we used recombinant plasmid positive controls as well as control plasmid of ß-globin fragments taken from human genes (Central Scientific Institute of Epidemiology Rospotrebnadzor). We have found that ß-HPV DNA predominated in fibroepithelial polyps (64%) and in the apparently healthy skin (54%) of immune-compromised patients versus 47% in the skin of healthy donors. Mixed infection was detected in fibroepithelial polyps of 57% in the immune-compromised patients. Viral consistence in the fibroepithelial polyps was higher than in the apparently normal donors' skin. The high detection of HPV DNA was found in fibroepithelial polyps and in the apparently healthy skin of immune-compromised patients whereas a high level of HPV DNA was only found in fibroepithelial polyps.

The diagnostic value of p63, p16, and p53 immunohistochemistry in distinguishing seborrheic keratosis, actinic keratosis, and Bowen's disease.

Seborrheic keratosis (SK), actinic keratosis (AK), and Bowen's disease (BD) are squamoproliferative disorders of the skin. Histologically, they may mimic each other and therefore, they might be misinterpreted, especially in small samples. The aim of this study is to clarify the expression of p63, p16, and p53 proteins in SK, AK, and BD and evaluate the efficacy of these markers in order to distinguish between the aforementioned lesions. A total of 46 cases were collected (15 SK, 16 AK, and 15 BD) and stained for p63, p16, and p53. The stain intensity and the cell distribution labeling were scored and then analyzed by SPSS software. All cases of BD which became positive for p53 revealed basal keratinocytes sparing. Instead, all or nearly all basal keratinocytes in AK cases were positive for this marker. These were also seen in p16 staining results and they were between AK and BD (P = .024). Our study demonstrates p16 and p53 are useful markers in separating AK and BD according to basal keratinocytes involvement and sparing, respectively.

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.

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.

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.