Rete Ridges Research Articles

“Interface” Dermatoses: Revisited

“Interface dermatoses” are defined as inflammatory dermatoses primarily affecting the interface elements along the dermoepidermal junction, resulting in epidermal basal cell damage. This epidermal basal cell damage can be of two forms: vacuolar/hydropic degeneration and filamentous degeneration (resulting in Civatte bodies). This may be associated with a range of secondary epidermal (atrophy to hypertrophy) and dermal changes (varying from simple effacement of the rete ridges to the diffuse dermal fibrosis/sclerosis). With so many variables, “Interface dermatitis” per se is not a diagnosis by itself but simply a reaction pattern, similar to “psoriasiform dermatitis” or “spongiotic dermatitis.” One should never use these terms as the final sign out diagnosis in reports, though in difficult cases one may allude to the reaction pattern and discuss the possible differentials. This article analyzes and discusses in detail, the basic pathogenesis behind the primary/secondary features associated with interface dermatoses and the steps involved in their histopathological evaluation; thorough knowledge of which may help one arrive at a specific diagnosis.

Differentiated Vulvar Intraepithelial Neoplasia: A Brief Review of Clinicopathologic Features.

Differentiated-type vulvar intraepithelial neoplasia (dVIN) is a non-human papilloma virus (HPV)-related precursor lesion to vulvar squamous carcinoma. The terminology has only become recognized clinically and histopathologically in recent years despite being described more than 50 years ago. As opposed to the HPV-related VIN (uVIN), dVIN has different features of histomorphology, risk of progression, and molecular pathogenesis. Notably, dVIN commonly develops in a background of chronic inflammatory dermatoses such as lichen sclerosis and lichen simplex chronicus. The recognition of dVIN remains a challenge owing to lack of accurate and reproducible diagnostic criteria. Morphologically, basal layer atypia, dyskeratosis, and elongation and anastomosis of the rete ridges are regarded as very useful diagnostic features. Ancillary tests can be very helpful to establish a definitive diagnosis in some ambiguous cases. In contrast to uVIN, dVIN is more likely to progress to vulvar squamous carcinoma in a shorter period. The goal of this review is to elaborate on the clinicopathologic characteristics and underline the key histologic features that best facilitate the diagnosis of dVIN.

Pushing and loss of elastic fibers are highly specific for melanoma and rare in melanocytic nevi.

The histopathological differentiation of melanocytic nevi from malignant melanoma (MM) is based on well-known criteria, and is straightforward in the vast majority of cases. However, there are few cases of melanocytic lesions (ML), the diagnosis of which is very challenging or even impossible. Here we have studied several morphological characteristics with particular focus on elastic fibers (EF) to identify features, helpful for the distinction between nevi and MM. In a monocentric retrospective study we have analyzed 14 morphological histological characteristics in 30 MMs and 90 nevi, encompassing 30 compound/dermal nevi, 30 junctional nevi, 30 dysplastic nevi. All consecutive cases were retrieved from the archives of our tertiary referral centre during the 6-month study period. Nine characteristics including loss of EF in the ML, loss of EF in lesional fibrosis, pushing of the EF, UV-elastosis, loss of rete ridges of the epidermis, regression of the ML, atrophy of the epidermis, pigment incontinence, and concentric eosinophilic fibroplasia (CEF) showed a statistical significant difference (p < 0.05 and at least an OR > 2) distinguishing nevi from MM. Loss of EF was found in 73.1% of MM cases, but in less than 2.5% of nevi. We identified nine morphological characteristics that are helpful to differentiate melanocytic nevi from MM. A loss of the EF in a ML appeared to be highly associated with MM.

Podoplanin suppresses the cell adhesion of epidermal keratinocytes via functional regulation of β1-integrin.

Epidermal stem cells adhere more efficiently to the extracellular matrix (ECM) than the less adhesive differentiating cells due to their high expression of cell adhesion molecules including β1-integrin. Podoplanin is majorly expressed in the markedly proliferative and differentiating basal cells of the wounded and psoriatic epidermis. This study was designed to reveal podoplanin's function in human epidermal keratinocytes (HEK) focusing on its interaction with β1-integrin. We analyzed the adhesion and differentiation of HEK in both podoplanin-overexpressing and -knock-down cells, considering their β1-integrin levels. The basal layer of IL-22-treated hyperproliferative reconstituted epidermis cells (simulating basal hyperproliferative psoriatic epidermal basal cells) expressed higher podoplanin levels than the untreated control cells. The adhesiveness of HaCaT cells, which do not express podoplanin, was reduced after the overexpression of podoplanin. HEK with podoplanin overexpression suppressed the cell adhesion to type I collagen (while downregulating β1-integrin functions) and podoplanin silencing augmented it (by increasing active ECM-bound β1-integrin). The increased cell adhesion to type I collagen induced by podoplanin silencing could be reversed by addition of P5D2, a neutralizing antibody against β1-integrin. In the psoriatic epidermis, podoplanin expression was especially upregulated on the rete ridges of the basal cell layer. This expression pattern was inversely correlated with the total/ECM-bound active β1-integrin-expression, which was stronger at the basal cell layer covering the dermal papillae. Our results indicate that podoplanin inhibits the cell ECM attachment by suppressing β1-integrin and initiating HEK differentiation. Podoplanin is presumably involved in the pathogenesis of psoriasis.

Aging in Skin of Color: Disruption to Elastic Fiber Organization Is Detrimental to Skin’s Biomechanical Function

Skin aging is a complex process involving the additive effects of time-dependent intrinsic aging and changes elicited via skin's interaction with the environment. Maintaining optimal skin function is essential for healthy aging across global populations; yet most research focuses on lightly pigmented skin (Fitzpatrick phototypes I-III), with little emphasis on skin of color (Fitzpatrick phototypes V-VI). Here, we explore the biomechanical and histologic consequences of aging in black African-American volunteers. We found that healthy young buttock and dorsal forearm skin was biomechanically resilient, highly elastic, and characterized histologically by strong interdigitation of rete ridges, abundant organized fibrillar collagen, and plentiful arrays of elastic fibers. In contrast, intrinsically aged buttock skin was significantly less resilient, less elastic, and was accompanied by effacement of rete ridges with reduced deposition of both elastic fibers and fibrillar collagens. In chronically photoexposed dorsal forearm, significant impairment of all biomechanical functions was identified, with complete flattening of rete ridges and marked depletion of elastic fibers and fibrillar collagens. We conclude that in skin of color, both intrinsic aging and photoaging significantly impact skin function and composition, despite the additional photoprotective properties of increased melanin. Improved public health advice regarding the consequences of chronic photoexposure and the importance of multimodal photoprotection use for all is of global significance.

Histochemical study of the distribution of epidermal melanoblasts and melanocytes in Asian human skin.

The classical study revealed the melanocyte density in the epidermis of many skin sites of humans. However, these data were obtained by counting melanocytes using dihydroxyphenylalanine (dopa)-treated epidermal sheets. Since rete ridges are developed well in human epidermis, there is a concern about the accuracy of these data. The accurate counting of the melanocyte density in the epidermis including the rete ridges should be performed using histological sections after the dopa treatment. Moreover, it is not known well how many melanoblasts are present in Asian epidermis. The aim of this study was to count the accurate number of melanocytes and melanoblasts. Normal skin sites of 9- to 77-year-old patients were fixed with buffered formalin and processed to the dopa and combined dopa-premelanin reactions. The numbers of cells positive to the dopa reaction (melanocytes) and to the combined dopa-premelanin reaction (melanoblasts and melanocytes) were scored. In the skin of arms, legs, back, and belly, similar density (approximately 110-120cells/0.1mm2 ) of melanocytes was observed, whereas in the skin of scalp, melanocyte density was much lower (approximately 70cells/0.1mm2 ). By contrast, the melanoblast density did not differ between skin sites (approximately 100cells/0.1mm2 ). These results suggest that the melanocyte density does not differ between skin sites except the scalp skin, and a certain number of melanoblasts are present in each skin site of Asian. Melanoblasts seem to be required for producing new melanocytes required to maintain epidermal homeostasis.

Acquired Cutaneous Lymphangiectasia Secondary to Cervical Cancer Treatment

To the Editor: A 78-year-old female patient presented with a 10-year history of pedunculated nodules on her vulvar area. She remembered that the nodules had increased both in number and size over the past 10 years. The patient did not complain of any subjective symptoms, such as itching or pain. Her history included total hysterectomy and radiation therapy for cervical cancer 35 years previously, and transurethral resection of bladder tumor for bladder cancer 2 years ago with no other risk factors for lymphedema reported. Physical examination revealed multiple pinkish pedunculated translucent nodules on the labia majora (Fig. 1). Localized edema on the vulvar area was seen. A biopsy specimen was obtained through harvesting a whole nodule with a punch. The biopsy demonstrated ectatic channels in the superficial and deep dermis (Figs. 2A, B). The spaces between collagen bundles were widened, reflecting an edematous condition. No occlusive lesions or related vascular components were identified. The channel was diffusely labeled with D2–40 (Fig. 2C). A diagnosis of acquired cutaneous lymphangiectasia (ACL) was made. The patient refused treatment after realizing the benign nature of the skin lesion.FIGURE 1.: Edematous appearance of vulvar area with overlying multiple vesiculonodular lesions.FIGURE 2.: Low power (A, hematoxylin–eosin, ×40) and high power (B, hematoxylin–eosin, ×100) histologic features show dilated lymphatic channels in the papillary dermis with hyperkeratotic epidermis. No atypical cells are observed. Endothelial cell linings of ectatic channels show positive reaction to D2–40 stain (C, D2–40, ×100).Lymphedema manifests as a result of ineffective lymphatic drainage due to architectural disruption with resultant increased hydrostatic pressure.1 Common causes of acquired lymphatic compromise are surgery and radiation therapy for the treatment of malignancy. Other predisposing factors are recurrent cellulitis, Crohn disease, and urogenital tuberculosis.2 A key histologic finding for lymphedema is edematous widening of intercollagenous spaces in the papillary dermis.3 In a similar way, ACL represents acquired dilatation of lymphatic channels secondary to external causes, but it results from a more chronic process.4–6 Clinically, ACL consists of clustered translucent vesicles and nodules ranging from colorless to purple due to varying red blood cell content.7 At the time of the very first development, the new lesion appears rather vesicular while it gradually becomes nodular as a result of tissue reorganization. Histologically, ACL shows ectatic lymphatic vessels lined by normal endothelial cells.5 The overlying epidermis may show hyperkeratosis, acanthosis, and the effacement of rete ridges. The pathologic findings in this case were consistent with these features of both lymphedema and lymphangiectasia. Differential diagnosis of this unusual manifestation must include more common conditions such as genital warts, condyloma accuminatum, and molluscum contagiosum. Reported treatment options for ACL in the literature are surgical excision, laser vaporization, cryotherapy, sclerotherapy, and electrodessication. Because ACL is infamous for its high recurrence rate when deeper lymphatic abnormalities are not sufficiently destroyed, radical excision is often favored. Hamida et al,2 suggested CO2 laser ablation as a conservative alternative to surgical intervention because of high patient tolerance and good cosmetic results.

A Case of Familial Focal Dermal Hypoplasia: A Report of 3 Cases in Consecutive Generations

Focal dermal hypoplasia (FDH), or Goltz syndrome, is a rare multisystem disorder affecting mesodermal and ectodermal structures, with the skin, eyes, teeth, and musculoskeletal systems most commonly affected. FDH results from mutations in the PORCN gene. Ninety-five percent of cases arise from novo mutations, whereas 5% are hereditary with an X-linked dominant inheritance pattern. Here, we describe an uncommon presentation of FDH in three consecutive generations. Patient 1 is an 8-month-old female born of non-consanguineous marriage who presented with diffuse alopecia of the scalp, linear hypopigmented, atrophic papules, and plaques with peripheral hyperpigmentation on the left hemiabdomen and right lateral leg along Blaschko's lines as well as syndactyly of the right second and third toes. Skin biopsy from the abdomen showed a thin epidermis with flattened rete ridges and massive dermal edema within collagen fibers and reactive capillaries. Family history was significant for similar skin lesions and bone deformities in her mother and similar skin lesions in her grandmother. Patient 2 (patient 1’s mother) is a 17-year-old female with similar linear hypopigmented, atrophic plaques with peripheral hyperpigmentation on the abdomen and right axilla, syndactyly of the right hand, patchy alopecia of the scalp, microdontia, teeth fusion, enamel defects, verrucous papillomas in the axillae and onycholysis. Patient 3 (patient 1’s grandmother), presented with similar hypopigmented, atrophic plaques on the abdomen and left arm.

Wide-Field In Vivo Confocal Microscopy of Meibomian Gland Acini and Rete Ridges in the Eyelid Margin.

PurposeIn vivo confocal microscopy (IVCM) has been widely used to evaluate changes in the meibomian glands (MGs) in response to age and disease. This study examined the structures described as MGs using wide-field IVCM and laser scanning confocal microscopy (LSCM) in situ and characterized their spatial distribution and localization relevant to the eyelid margin.MethodsIVCM was performed on 30 subjects aged 18 to 38 to visualize structures in the eyelid margin. Size, shape, and distribution characteristics were measured, and individual frames were montaged into wide-field images. Structures observed on IVCM were then visualized using LSCM of whole-mount and cryosectioned cadaver eyelids stained with Nile red, mucin-1 (MUC1), laminin-5, and 4′,6-diamidine-2′-phenylindole dihydrochloride.ResultsThe size, distribution, and staining patterns of the reflective structures seen on IVCM did not correspond to the MGs in cadaver eyelids. Instead, staining profiles indicated that these structures corresponded to the rete ridges present at the dermal–epidermal junction. Wide-field imaging showed a densely populated field of rete ridges with distinct size and shape characteristics depending on their location relative to the meibomian orifices. A distal shift of the mucocutaneous junction (MCJ) was evident in some eyelids.ConclusionsIVCM is unable to visualize MGs in the human eyelid margin due to light attenuation at that tissue depth. LSCM confirms that these structures are rete ridges located at the dermal–epidermal junction. Alterations in the structure of the dermal–epidermal junction within the eyelid margin indicate a shifting of the MCJ and may impact tear film dynamics.

Development of psoriasis by continuous neutrophil infiltration into the epidermis

Remarkable effects of anti-IL-17A and anti-IL-23 antibodies on psoriasis indicate deep involvement of IL-23/Th17 axis in the pathogenesis of psoriasis. According to the current immune theory, activation of dendritic cells initiates the generation of this axis. However, this theory is not enough to explain the mechanism, because the process of this activation is obscure and the antigen that is recognized by antigen-presenting cells and pathogenic T cells has long been unidentified. Therefore, I thought of another theory as follows. Neutrophils are attracted by LTB4 at subcorneal portion and infiltrate into the epidermis. At the time of neutrophil migration through the basement membrane, basal keratinocytes in G0/G1 phase enter the cell cycle and begin to proliferate, according to the principle, "detachment-mediated cell proliferation." This passing is continuously repeated and leads to elongation of rete ridges. The IL-23/Th17 axis is generated by interactions between infiltrated neutrophils and keratinocytes. Briefly, neutrophils infiltrated into the epidermis secrete IL-17A, which acts on keratinocytes to express CCL20, a ligand for the chemokine receptor CCR6. Keratinocytes perturbed by neutrophil infiltration produce HSP70, followed by production of IL-23 via TLR4 using HSP70 as an endogenous ligand for TLR4. Natural Th17 cells expressing CCR6 are recruited to psoriatic epidermis and expand there in the presence of IL-23 and IL-1β. In this manner, the framework of the IL-23/Th17 axis is created, which acts to maintain or exacerbate psoriasis. Noteworthy is the fact that this axis causes positive feedback loop, starting from IL-17A production by neutrophils and ending in IL-17A production by nTh17 cells. Therapeutic mechanisms of anti-IL-17A and anti-IL-23 antibodies, targeting neutrophils, were also described.

Treatment of limb wounds of horses with orf virus IL-10 and VEGF-E accelerates resolution of exuberant granulation tissue, but does not prevent its development.

Bandaging of limb wounds in horses leads to formation of exuberant granulation tissue (EGT) that retards healing due to protracted inflammation, aberrant vascularisation and delayed epithelialisation. EGT is not observed if wounds are left undressed or when wounds are on the body. A previous study showed that short-term administration of proteins derived from orf virus dampened inflammation and promoted epithelialisation of open wounds in horses. Here, we investigated the impact of orf virus interleukin-10 and vascular endothelial growth factor-E on the development and resolution of EGT. Excisional wounds were created on the forelimb of four horses, and bandages were maintained until full healing to induce EGT formation. Matching body wounds were created to ensure EGT was limited to the limb, and to differentiate the effects of the viral proteins on normal healing and on EGT formation. Viral proteins or the hydrogel vehicle control were administered topically to site-matched wounds at day 1, with repeat administration at day 8. Wound healing and EGT formation were monitored macroscopically. Wound margin samples were harvested at 2, 7 and 14 days, and at full healing, with histology used to observe epithelialisation, immunofluorescence used to detect inflammatory cells, angiogenesis and cell death, and qPCR to measure expression of genes regulating inflammation and angiogenesis. Limb wounds developed EGT, and exhibited slower healing than body wounds. Viral protein treatment did not accelerate healing at either location nor limit EGT formation in limb wounds. Treatment of limb wounds did however increase epithelialisation and angiogenesis, without dampening inflammatory cell infiltration or gene expression. The healed wounds also had less occlusion and death of blood vessels and fewer epidermal rete ridges following viral protein treatment. These findings indicate that the viral protein treatment does not suppress wound inflammation or EGT formation, but does promote vascular and epidermal repair and EGT resolution.

Are quantitative histopathologic criteria capable of differentiating psoriasis from chronic dermatitis?

BackgroundThere are overlapping features in histopathologic characteristics of psoriasis and chronic dermatitis, which sometimes make the correct diagnosis difficult.ObjectiveThe aim of this study was to compare the histopathologic diagnostic features of psoriasis with chronic dermatitis quantitatively.Patients and methodsIn this study, 30 patients with psoriasis and 30 patients with chronic dermatitis were included. Diagnosis of psoriasis or chronic dermatitis was based on clinicopathologic correlation. Photos of histopathologic slides were provided by LABOMED Digital Camera and LABOMED Microscope. Width and length of rete ridges, minimal thickness of suprapapillary plates, thickness of epidermis, thickness of hyperkeratotic layer, and minimal thickness of granular layer were determined using Pixel Pro software on micrometer scale.ResultsSuprapapillary plates and granular layer were significantly thicker in patients with chronic dermatitis compared with patients with psoriasis. The rete ridges were longer and wider, the epidermis was thicker, and the parakeratotic layer was also thicker in patients with psoriasis compared with patients with chronic dermatitis, and the difference between these corresponding parameters in the two groups was statistically significant except for thickness of parakeratotic layer. Moreover, the mean ratio of minimal suprapapillary plate’s thickness to epidermal thickness and the mean ratio of minimal granular layer’s thickness to parakeratotic layer’s thickness were significantly higher in patients with chronic dermatitis compared with those with psoriasis.ConclusionDespite overlapping histopathologic features in psoriasis and chronic dermatitis, quantitative histopathologic criteria might be valuable for differentiation of these two conditions. Ratios of minimal suprapapillary plate’s thickness to epidermal thickness and minimal granular layer’s thickness to parakeratotic layer’s thickness can be particularly helpful in this regard.

Acrodermatitis continua of Hallopeau successfully treated only with infliximab: A case report

AbstractA 22‐year‐old man presented with a 2‐month history of rapidly progressing pustular eruptions on the accrual regions of his fingers and toes with local arthralgia and severe nail destruction. A histological examination revealed parakeratosis, hyperkeratosis and elongation of the rete ridges of the epidermis with exocytosis of neutrophils forming spongiform pustules of Kogoj. Based on these findings, we diagnosed this case as acrodermatitis continua of Hallopeau (ACH). ACH, a variant of pustular psoriasis, is often resistant to various topical treatments, and the patient experienced prominent decline in his quality of life. Therefore, we decided to use infliximab in the present case. After the fourth administration of infliximab alone, the patient's digital arthralgia and pustular eruptions disappeared completely, and the long‐term administration of infliximab drastically reduced all of the patient's symptoms of ACH, including the nail lesions without any adverse events or recurrence. Our findings suggest that ACH shares a disease spectrum with plaque‐type and pustular psoriasis. In addition, biologic agents such as a tumor necrosis factor‐α inhibitor are useful for treating patients with ACH just as those with psoriasis and may even be used alone.

Noninvasive assessment of skin structure by combined photothermal radiometry and optical spectroscopy: coregistration with multiphoton microscopy.

We are combining two optical techniques, pulsed photothermal radiometry (PPTR) and diffuse reflectance spectroscopy (DRS), for noninvasive assessment of the structure and composition of human skin in vivo. The analysis involves simultaneous multidimensional fitting of the measured PPTR signals and DRS spectra with predictions of a numerical model of light transport (Monte Carlo) in a four-layer model optical model of human skin, accounting for the epidermis, papillary and reticular dermis, and subcutis. The assessed epidermal thickness values were tested by coregistration with a multiphoton microscope, which provides vertical sectioning capability based on two-photon excited fluorescence and second-harmonic generation in selected skin components. The comparison shows that these values correspond well to the maximal epidermal thicknesses measured in the multiphoton microscopy images, the rete ridges.

702 Age-dependent transformation of skin biomechanical properties and micromorphology during infancy and childhood

We investigated for the first time the correlation between the maturation of biomechanical properties of the skin and the evolution of skin topography and micromorphology from infancy to early adulthood. 70 subjects in 7 age groups: 1-15 days, 5 weeks, 5-7 months, 2 years, 4-5 years, 7-8 years, and 20-35 years were included. Skin properties were examined by cutometry and reflectance confocal microscopy (RCM) in vivo, and by immunohistochemistry (IHC) in a limited number of foreskin biopsy samples. Cutometry showed that skin elasticity increased from infancy to 2 years. The viscoelastic component decreased from infancy to adulthood. Total recovery was slightly higher at older ages and total deformation did not vary between age groups. None of the parameters were correlated with stratum corneum (SC) hydration. RCM showed that thickness of the SC and supra papillary epidermis increased with age. The homogeneity and furrow architecture of SC changed dramatically between infants and older children. Dermal papillae increased in number with age, whereas rete ridge thickness remained stable. Circular cuffing of the follicle by collagen fibers was observed only in newborns, age at which collagen fibers were fibrillar and showed a parallel orientation. IHC showed that both fibrillin and elastin fibers increased in length and intensity with age, especially at the dermal-epidermal junction. These data demonstrate the biochemical and structural evolution of the dermis during postnatal development. These changes in these skin biomechanical properties are related to structural maturation rather than hydration. Our data support a contribution of mechanical forces to dermal maturation postnatally.

Acuidade Diagnóstica da Dermatoscopia em Lesões Melanocíticas: Estudo Retrospetivo com Correlação Histológica.

Introdução: A dermatoscopia é uma técnica in vivo não-invasiva, amplamente usada como ferramenta complementar no estudo de lesões pigmentadas da pele, permitindo um diagnóstico mais precoce do melanoma cutâneo. O objetivo deste estudo é avaliar a acuidade diagnóstica da dermatoscopia em lesões melanocíticas e alargar as correlações dermatoscopia-histopatologia já estabelecidas.Material e Métodos: Estudo retrospetivo utilizando a base de dados da Consulta de Dermatoscopia e Lesões Pigmentadas e a base de dados da Histologia de um Serviço de Dermatologia. Cada lesão melanocítica foi avaliada segundo parâmetros dermatoscópicos e histológicos. Determinou-se a concordância entre os diagnósticos e entre os parâmetros avaliados.Resultados: Verificou-se um ratio maligno/benigno de 1:9,2. Obteve-se uma concordância razoável entre os diagnósticos dermatoscópicos e histológicos. Para os melanomas obteve-se uma concordância excelente, tendo a dermatoscopia revelado uma sensibilidade de 92,9% e especificidade de 96,9%. Observou-se concordância entre padrão reticular e a presença de fusão de cristas e atipia citológica; padrão globular e presença de tecas; rede atípica e a presença de fibrose e atipia citológica; blotches e paraqueratose pigmentada; véu azul esbranquiçado e a presença de fibrose.Conclusão: Apesar de algumas limitações e achados não esperados, muitos dos resultados do presente estudo vêm na continuidade do que tem vindo a ser descrito na literatura, mostrando uma elevada sensibilidade e especificidade da dermatoscopia no diagnóstico de melanoma, o que se reflete numa otimização do diagnóstico precoce sem necessidade de aumento do número total de excisões de lesões pigmentadas.

Dysplastic features relevant to malignant transformation in atrophic epithelium of oral submucous fibrosis: A preliminary study.

The grading of oral epithelial dysplasia (OED) is not applicable to oral submucous fibrosis (OSMF) cases due to the presence of atrophic epithelium. The mucosal margins associated with resected OSCC specimens are often closely related to transformed cells. In this study, we compared the histomorphological alterations (dysplastic features) in the atrophic epithelium of OSMF patients with the mucosal margins of OSCC associated with OSMF (OSCC-OSMF). We evaluated 17 dysplastic features in 37 patients with OSMF (biopsy site: buccal mucosa) and 37 patients with OSCC-OSMF (mucosal margins involving buccal mucosa) using histopathological staining. Dysplastic features, such as keratin pearls within rete ridges, nuclear pleomorphism, and atypical mitotic figures, were not observed in the epithelium of the OSMF or OSCC-OSMF groups. Basal cell hyperplasia (P=.016), abnormal superficial mitosis (P=.010), increased nuclear-cytoplasmic ratio (P=.034), and hyperchromasia (P=.031) were predominantly seen in the OSCC-OSMF group. We found no statistically significant differences in the following parameters: irregular epithelial stratification (P=1.00), loss of basal cell polarity (P=.237), presence of drop-shaped rete ridges (P=.077), increased number of mitotic figures (P=.154), premature keratinization in single cells (P=.499), anisonucleosis (P=.289), anisocytosis (P=.079), cellular pleomorphism (P=.317), and increased number and size of nucleoli (P=.129). Increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, and hyperchromasia are high-risk features for OSMF, and affected patients should be followed on a priority basis for the early detection of OSCC.

Efficacy of nonablative fractional laser in the treatment of striae gravidarum: a clinical observation

Objective To assess the efficacy and safety of nonablative 1 565-nm Er:Glass fractional laser in the treatment of striae gravidarum. Methods The left and right sides of the abdomens of 30 subjects with striae gravidarum were divided into 2 groups by simple randomization: treatment group treated with nonablative 1 565-nm Er:Glass fractional laser every 4 weeks for 3 sessions, and control group receiving no treatment. These subjects were followed up at the baseline, 4th, 8th and 12th week. At the same time, photos were taken, the skin flexibility was evaluated, and the width of striae was measured. Four weeks after the final treatment, clinical improvement was evaluated by 2 doctors, who were blind to the therapeutic protocol, according to clinical photos and three-dimensional (3D) images, and satisfaction scores were also evaluated. Skin biopsies were taken from the left and right sides of the abdomens of 3 subjects, and subjected to histopathological examination. Four months after the final treatment, all the subjects were telephoned for evaluation of adverse reactions and recurrence. Results A total of 27 subjects completed the whole trial. Four weeks after the final treatment, 25 (92.6%) of the 27 subjects were considered to achieve an improvement by doctors. However, 21 (77.8%) of the 27 subjects considered themselves to achieve an improvement. After 3 sessions of treatment, the treatment group showed a significant decrease in the largest width of striae from 4.852 mm to 3.296 mm (P < 0.001) and a significant increase in skin flexibility from 0.803 to 0.878 (P < 0.001) . Histopathologically, the control group showed obviously atrophic epidermis and decreased collagen and elastin in the dermis, while the treatment group showed thickened epidermis and dermis, extended rete ridges, and increased collagen and elastic fibers which arranged more regularly. Immediate adverse reactions during the treatment included erythema and edema, and other adverse reactions included mild crust, itching and post-inflammatory hyperpigmentation (PIH) . PIH was improved at 4 months after the final treatment compared with that at 4 weeks after the final treatment. Conclusion The nonablative 1 565-nm Er:Glass fractional laser can markedly improve the width and appearance of striae gravidarum, and increase skin flexibility in the treatment region. Key words: Laser therapy; Treatment outcome; Safety; Striae gravidarum; 1565 nm Er:Glass fractional laser

Linear Psoriasis: A Case Report of a 71-Year-Old Female

A 71-year-old woman presented with a one-month history of pruritus, burning, flaky, and erythematous plaques. The lesions had a very narrow lineal distribution, extending from the lateral left sole to the left popliteal region. Microscopically, the skin biopsy sample revealed orthokeratosis, parakeratosis and traumatized Koebnerization. Elongation of rete ridges was not prominent. The patient had a good clinical response to oral prednisone. Linear psoriasis is a rare variant of psoriasis of unknown etiology. Approximately 23 reports have been published in the English literature. The main differential diagnosis is Inflammatory linear verrucous epidermal nevus (ILVEN). Thorough clinicopathologic findings and response to treatment are all required in the diagnosis and management of this rare form of psoriasis.

A methodology for the production of microfabricated electrospun membranes for the creation of new skin regeneration models

The continual renewal of the epidermis is thought to be related to the presence of populations of epidermal stem cells residing in physically protected microenvironments (rete ridges) directly influenced by the presence of mesenchymal fibroblasts. Current skin in vitro models do acknowledge the influence of stromal fibroblasts in skin reorganisation but the study of the effect of the rete ridge-microenvironment on epidermal renewal still remains a rich topic for exploration. We suggest there is a need for the development of new in vitro models in which to study epithelial stem cell behaviour prior to translating these models into the design of new cell-free biomaterial devices for skin reconstruction. In this study, we aimed to develop new prototype epidermal-like layers containing pseudo-rete ridge structures for studying the effect of topographical cues on epithelial cell behaviour. The models were designed using a range of three-dimensional electrospun microfabricated scaffolds. This was achieved via the utilisation of polyethylene glycol diacrylate to produce a reusable template over which poly(3-hydrroxybutyrate-co-3-hydroxyvalerate) was electrospun. Initial investigations studied the behaviour of keratinocytes cultured on models using plain scaffolds (without the presence of intricate topography) versus keratinocytes cultured on scaffolds containing microfeatures.