Numerous multinucleated giant cells in cutaneous epithelioid angiosarcoma and pulmonary metastasis: A unique observation with potential diagnostic pitfalls

The histopathologic diagnosis of poorly differentiated cutaneous angiosarcoma can be challenging. We report a case of cutaneous epithelioid angiosarcoma with numerous multinucleated giant cells (MGCs) developing pulmonary metastasis. A 79-year-old man presented with a red-purple plaque on the scalp. A skin biopsy revealed epithelioid cell proliferation, admixed with numerous MGCs, and background hemorrhage. Vascular spaces were focally present and lined by atypical endothelial cells, including MGCs. Immunohistochemically, tumor cells, including MGCs, were positive for CD31, D2-40, and ERG. The patient received radiation therapy and chemotherapy, after which a follow-up CT scan revealed symptomless pneumothorax and pulmonary metastases. The patient received palliative partial lung resection, and the specimen revealed histopathological and immunohistochemical features similar to the primary cutaneous lesion. Our report expands the morphologic spectrum of cutaneous epithelioid angiosarcoma. Cutaneous angiosarcoma is an aggressive neoplasm; thus, awareness of this rare manifestation is important.

Possible relation of cathepsin C activity and seasonal fluctuation of skin lesions in Papillon-Lefèvre syndrome

Our patient with Papillon–Lefèvre syndrome with a novel p.G430V and recurrent p.G301S missense mutation showing aggravation of skin lesions in wintertime. A temperature-dependent cathepsin C enzymatic activity study indicates a possible association between seasonal fluctuations, minimal dental involvement and temperature.

Two cases of infancy associated eosinophilic pustular folliculitis (I-EPF) comparing the profile of infiltrating cells with classic EPF by immunohistochemical study

Infancy associated eosinophilic pustular folliculitis (I-EPF) is a clinical variant of EPF that develops in childhood. Previous studies have suggested that I-EPF exhibits clinical and histological differences distinct from other variants, including classic EPF. Herein, we report two patients with I-EPF treated with topical indomethacin. These two cases exhibited less perifollicular and more perivascular eosinophilic infiltration, which is different in distribution from that of classic EPF. Immunohistochemical study demonstrated that the infiltrating mononuclear cells were CD4-dominant T cells in classic EPF and I-EPF, whereas the number of CD68-positive cells was significantly higher in classic EPF than in I-EPF. Immunohistochemical staining was also performed for eosinophilic pustular folliculitis (HPGDS), which has been reported to induce eosinophils and is a therapeutic target of indomethacin in classic EPF. HPGDS-positive cells were also observed in I-EPF, which may explain the effectiveness of topical indomethacin. Although clinical and histopathological features of I-EPF are different from other variants, the arachidonic acid pathway could be involved in eosinophil infiltration, not only in classic EPF but also in I-EPF.

Ultrasonographic findings in nevus lipomatosus cutaneous superficialis: What differentiates this tumor from other soft tissue tumors?

Nevus lipomatosus cutaneous superficialis is a rare, benign hamartoma characterized by mature adipocyte proliferation in the dermis. It is frequently difficult to distinguish clinically from soft tissue tumors, including lipoma, neurofibroma, venous malformation, and angiolipoma. Notably, the classical form, which shows multiple and sometimes enlarged nodules, is difficult to differentiate from liposarcoma based on clinical examination, computed tomography, and magnetic resonance imaging findings. Therefore, to ascertain the utility of ultrasonography in diagnosing nevus lipomatosus cutaneous superficialis, sonographic examinations were performed on eight patients with nevus lipomatosus cutaneous superficialis. All patients had ill-defined hyperechoic masses in the dermis or from the dermis to the subcutis, and the posterior echoes were attenuated in seven patients. Color Doppler sonography revealed no blood flow to the lesions. Ultrasound images were created using the reflections of ultrasound waves at interfaces with different acoustic impedances. Therefore, it is assumed that, in nevus lipomatosus cutaneous superficialis, the ultrasound beam is scattered by ectopic mature adipocytes intermingled with collagen bundles, which are shown as hyperechoic masses. Furthermore, the scattering of the ultrasound beam is thought to reduce tissue penetration, which may attenuate the posterior echo.

Interleukin-18 as a severity marker and novel potential therapeutic target for epidermolytic ichthyosis

BACKGROUND

Epidermolytic ichthyosis (EI) is a major form of nonsyndromic inherited ichthyosis, characterized by erythroderma, marked hyperkeratosis and scale, bulla and erosion at birth, associated with KRT1/KRT10 mutations. The cytokine and chemokine profiles in EI are poorly understood, and specific treatment options have not been established.

AIM

To explore novel biomarkers and therapeutic targets in patients with EI.

METHODS

We analysed cytokine levels in serum and skin samples from 10 patients with inherited ichthyosis, including seven patients with EI. Wild-type and mutant KRT1 constructs were established and transfected into HaCaT cells, an immortalized keratinocyte cell line, for in vitro immunoblotting and immunocytochemistry analyses.

RESULTS

Multiplex cytokine/chemokine analysis revealed that 10 cytokines/chemokines [interleukin (IL)-1β, IL-4, IL-17A, IL-16, IL-18, IL-1 receptor-α, macrophage colony-stimulating factor, interferon-α2, basic fibroblast growth factor and monocyte chemotactic protein-3] were significantly increased in patients with EI. Furthermore, IL-18 levels were significantly higher in patients with EI [n = 7; 2714.1 (1438.0) pg mL-1] than in healthy controls [n = 11; 218.4 (28.4) pg mL-1, P < 0.01]. Immunohistochemical analyses showed that IL-18 expression was elevated in skin samples from patients with EI. Serum IL-18 levels correlated with the severity of ichthyosis, as measured by the Ichthyosis Scoring System. Immunoblotting analysis revealed that mature IL-18 levels were increased in the supernatant of mutant KRT1 expressing HaCaT cells. Additionally, these cells showed NLRP3 aggregation in the cytoplasm and ASC clustered around mutant keratin aggregations. These findings suggest that mutant keratin might promote the activation of the NLRP3 inflammasome and its downstream caspase-1-mediated IL-18 release in keratinocytes from patients with EI.

CONCLUSIONS

Our results suggest that serum IL-18 is a severity marker released from the skin of patients with EI. Blockade of IL-18 may be a useful novel therapeutic option for patients with EI.

Cas9-guided haplotyping of three truncation variants in autosomal recessive disease

An autosomal recessive disease is caused by biallelic loss-of-function mutations. However, when more than two disease-causing variants are found in a patient's gene, it is challenging to determine which two of the variants are responsible for the disease phenotype. Here, to decipher the pathogenic variants by precise haplotyping, we applied nanopore Cas9-targeted sequencing (nCATS) to three truncation COL7A1 variants detected in a patient with recessive dystrophic epidermolysis bullosa (EB). The distance between the most 5' and 3' variants was approximately 19 kb at the level of genomic DNA. nCATS successfully demonstrated that the most 5' and 3' variants were located in one allele while the variant in between was located in the other allele. Interestingly, the proband's mother, who was phenotypically intact, was heterozygous for the allele that harbored the two truncation variants, which could otherwise be misinterpreted as those of typical recessive dystrophic EB. Our study highlights the usefulness of nCATS as a tool to determine haplotypes of complicated genetic cases. Haplotyping of multiple variants in a gene can determine which variant should be therapeutically targeted when nucleotide-specific gene therapy is applied. This article is protected by copyright. All rights reserved.

Deep Neural Network for Early Image Diagnosis of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

BACKGROUND

Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is a life-threatening cutaneous adverse drug reaction (cADR). Distinguishing SJS/TEN from nonsevere cADRs is difficult, especially in the early stages of the disease.

OBJECTIVE

To overcome this limitation, we developed a computer-aided diagnosis system for the early diagnosis of SJS/TEN, powered by a deep convolutional neural network (DCNN).

METHODS

We trained a DCNN using a dataset of 26,661 individual lesion images obtained from 123 patients with a diagnosis of SJS/TEN or nonsevere cADRs. The DCNN's accuracy of classification was compared with that of 10 board-certified dermatologists and 24 trainee dermatologists.

RESULTS

The DCNN achieved 84.6% sensitivity (95% confidence interval [CI], 80.6-88.6), whereas the sensitivities of the board-certified dermatologists and trainee dermatologists were 31.3 % (95% CI, 20.9-41.8; P < .0001) and 27.8% (95% CI, 22.6-32.5; P < .0001), respectively. The negative predictive value was 94.6% (95% CI, 93.2-96.0) for the DCNN, 68.1% (95% CI, 66.1-70.0; P < .0001) for the board-certified dermatologists, and 67.4% (95% CI, 66.1-68.7; P < .0001) for the trainee dermatologists. The area under the receiver operating characteristic curve of the DCNN for a SJS/TEN diagnosis was 0.873, which was significantly higher than that for all board-certified dermatologists and trainee dermatologists.

CONCLUSIONS

We developed a DCNN to classify SJS/TEN and nonsevere cADRs based on individual lesion images of erythema. The DCNN performed significantly better than did dermatologists in classifying SJS/TEN from skin images.

Current topics in Epidermolysis bullosa: Pathophysiology and therapeutic challenges

Epidermolysis bullosa (EB) is a group of inherited skin and mucosal fragility disorders resulting from mutations in genes encoding basement membrane zone (BMZ) components or proteins that maintain the integrity of BMZ and adjacent keratinocytes. More than 30 years have passed since the first causative gene for EB was identified, and over 40 genes are now known to be responsible for the protean collection of mechanobullous diseases included under the umbrella term of EB. Through the elucidation of disease mechanisms using human skin samples, animal models, and cultured cells, we have now reached the stage of developing more effective therapeutics for EB. This review will initially focus on what is known about blister wound healing in EB, since recent and emerging basic science data are very relevant to clinical translation and therapeutic strategies for patients. We then place these studies in the context of the latest information on gene therapy, read-through therapy, and cell therapy that provide optimism for improved clinical management of people living with EB.

Wnt/β-Catenin Signaling Stabilizes Hemidesmosomes in Keratinocytes

Hemidesmosomes (HDs) are adhesion complexes that promote epithelial-stromal attachment in stratified and complex epithelia, including the epidermis. In various biological processes, such as differentiation and migration of epidermal keratinocytes during wound healing or carcinoma invasion, quick assembly and disassembly of HDs are prerequisites. In this study, we show that inhibition of Wnt/β-catenin signaling disturbs HD organization in keratinocytes. Screening with inhibitors identified the depletion of HD components and HD-like structures through Wnt inhibition, but keratinocyte differentiation was not affected. Wnt inhibition significantly diminished plectin and type XVII collagen expression in the basal side of Wnt-inhibited cells and the dermo-epidermal junction of the Wnt-inactive murine basal epidermis. Similar to Wnt inhibition, PLEC-knockout cells or cells with plectin-type XVII collagen binding defects showed type XVII collagen reduction in the basal side of the cells, implying the possible involvement of Wnt/β-catenin signaling in HD assembly. Atypical protein kinase C inhibition ameliorated the phenotypes of Wnt-inhibited cells. These findings show that Wnt/β-catenin signaling regulates the localization of HD components in keratinocytes and that the atypical protein kinase C pathway is involved in Wnt inhibition‒induced HD disarrangement. Our study suggests that the Wnt signaling pathway could be a potential therapeutic target for treating HD-defective diseases, such as epidermolysis bullosa.

Acral persistent papular mucinosis: A case report and summary of 24 Japanese cases

Acral persistent papular mucinosis is a rare subtype of localized lichen myxedematosus. We report a case of a 41-year-old woman with acral persistent papular mucinosis. She had a 5-year history of multiple, scattered, whitish papules, on the back of both hands, of 2-5 mm in diameter. Histopathological examination revealed a focal, fairly circumscribed area with sparse collagen fibers in the upper and middle dermis. The circumscribed area was positively stained with Alcian blue. The papules were clinically and histologically diagnosed as acral persistent papular mucinosis. We also summarized 24 Japanese acral persistent papular mucinosis cases, including ours. Although acral persistent papular mucinosis occurs predominantly in women according to overseas reports, the male : female ratio is 5:7 in Japan. It has been reported that tranilast (N-[3,4-dimethoxycinnamoyl]-anthranilic acid) was effective in two Japanese cases. In our case, the patient had been treated with tranilast for 2 months without improvement. Further studies are required to confirm the efficacy of tranilast for acral persistent papular mucinosis.

Advances in gene therapy and their application to skin diseases: A review

With recent advances in genetic engineering technology, gene therapy is now being considered as a treatment not only for congenital diseases but also acquired diseases, such as cancer. Gene therapeutic agents for hereditary immune disorders, haemophilia, retinal diseases, neurodegenerative diseases, and lymphoma have been approved in the United States and Europe. In the field of dermatology, clinical trials of gene therapy have been conducted, because the skin is an easily accessible organ that represents an attractive tissue for gene therapy. In recent years, gene therapy has been attempted for a variety of skin diseases, such as genodermatoses (including epidermolysis bullosa and Netherton syndrome), cutaneous lymphoma, and malignant melanoma. As a result, it is difficult to grasp the current status of gene therapy in dermatology. This review focuses on each of the gene-transfer techniques currently in use and describes the current status of gene therapy for skin diseases using each technology.

Localized bullous pemphigoid recurring at different sites: two case reports

BACKGROUND

Localized bullous pemphigoid is a relatively rare variant of bullous pemphigoid. Lesions develop only in localized sites including the legs or palms and soles and occasionally appear in trauma-affected body parts. In some cases, the skin lesions spread to the entire body, while in others, they remain localized and improve spontaneously or with treatment using topical corticosteroids. Rarely, the lesions recur at sites different from those of the original lesions, after the initial lesions have completely healed.

OBJECTIVES

To investigate the clinical course of patients with localized bullous pemphigoid.

MATERIALS AND METHODS

Two cases of localized bullous pemphigoid that recurred at sites distant from those of the initial lesions were reported.

RESULTS

Case 1 involved a 62-year-old woman with mucous membrane pemphigoid. One year after the improvement of mucosal symptoms, new lesions appeared in the periumbilical area. The lesions resolved after topical corticosteroid treatment. This case is the first report of localized bullous pemphigoid occurring after an improvement of mucous membrane pemphigoid. Case 2 involved an 81-year-old man who bruised his right lower leg and developed erythematous plaques and tense bullae. The patient was diagnosed with localized bullous pemphigoid and was treated with topical corticosteroid. However, six months later, new lesions appeared on the palms and soles. The patient responded well to oral prednisolone.

CONCLUSIONS

Since localized bullous pemphigoid may have a variable clinical course, clinicians should observe affected patients carefully over a long period of time.

Electron Microscopic and Immunohistochemical Findings of the Epidermal Basement Membrane in Two Families with Nail-patella Syndrome

Nail-patella syndrome is an autosomal dominant disorder characterized by nail dysplasia and skeletal anomaly. Some patients have been shown to have ultrastructural abnormalities of the glomerular basement membrane that result in nephrosis. However, little has been reported on the epidermal basement membrane in this condition. This paper reports 2 families with nail-patella syndrome. Direct sequencing analysis of LMX1B revealed that family 1 and family 2 were heterozygous for the mutations c.140-1G>C and c.326+1G>C, respectively. To evaluate the epidermal basement membrane zone, ultrastructural and immunohistochemical analyses were performed using skin specimens obtained from the dorsal thumb. Electron microscopy showed intact hemidesmosomes, lamina lucida, lamina densa, and anchoring fibrils. Immunofluorescence studies with antibodies against components of the epidermal basement membrane zone revealed a normal expression pattern among the components, including type IV collagen. These data suggest that nail dysplasia in patients with nail-patella syndrome is not caused by structural abnormalities of the epidermal basement membrane.

Unusual Bone Lesions with Osteonecrosis Mimicking Bone Metastasis of Squamous Cell Carcinoma in Recessive Dystrophic Epidermolysis Bullosa

Some bone lesions are reported to mimic bone metastasis on imaging tests. Herein, we report a case of a 55-year-old Japanese man who presented with a skin tumor on the left lower extremity. He also had a history of recurrent generalized cutaneous blister and erosion formation since childhood. His skin lesions were diagnosed as cutaneous squamous cell carcinoma complicated by recessive dystrophic epidermolysis bullosa. Magnetic resonance imaging of the left lower extremity detected multiple focal bone lesions mimicking bone metastases in the left femur and tibia. However, bone biopsy revealed that the bone lesions were osteonecrosis without tumor cells. We suggest that cancer-induced osteonecrosis should be included in the differential diagnosis of bone lesions suspected of being metastases on magnetic resonance imaging.

Cultured Epidermal Autografts from Clinically Revertant Skin as a Potential Wound Treatment for Recessive Dystrophic Epidermolysis Bullosa

Inherited skin disorders have been reported recently to have sporadic normal-looking areas, where a portion of the keratinocytes have recovered from causative gene mutations (revertant mosaicism). We observed a case of recessive dystrophic epidermolysis bullosa treated with cultured epidermal autografts (CEAs), whose CEA-grafted site remained epithelized for 16 years. We proved that the CEA product and the grafted area included cells with revertant mosaicism. Based on these findings, we conducted an investigator-initiated clinical trial of CEAs from clinically revertant skin for recessive dystrophic epidermolysis bullosa. The donor sites were analyzed by genetic analysis, immunofluorescence, electron microscopy, and quantification of the reverted mRNA with deep sequencing. The primary endpoint was the ulcer epithelization rate per patient at 4 weeks after the last CEA application. Three patients with recessive dystrophic epidermolysis bullosa with 8 ulcers were enrolled, and the epithelization rate for each patient at the primary endpoint was 87.7%, 100%, and 57.0%, respectively. The clinical effects were found to persist for at least 76 weeks after CEA transplantation. One of the three patients had apparent revertant mosaicism in the donor skin and in the post-transplanted area. CEAs from clinically normal skin are a potentially well-tolerated treatment for recessive dystrophic epidermolysis bullosa.