A Case of Merkel Cell Carcinoma of Unknown Primary Origin Presenting With High Merkel Cell Polyomavirus DNA Levels in Swabs Obtained From the Normal Skin.

Merkel cell carcinoma is a rare neuroendocrine tumor with high mortality. It is well known that clonal integration of the Merkel cell polyomavirus into the dermal precursor cells is a hypothesized pathway in Merkel cell carcinoma pathogenesis. Here, we demonstrate a case of Merkel cell carcinoma (primary origin unknown) presenting with high Merkel cell polyomavirus DNA levels in swabs obtained from normal skin.

Beneficial effects of ultrafine bubble shower on a mouse model of atopic dermatitis.

Introduction: Atopic dermatitis (AD) is a common and relapsing skin disease characterized by skin barrier dysfunction, inflammation, and chronic pruritus. Both cutaneous barrier dysfunction and immune dysregulation are critical etiologies of the pathology of AD. Although various anti-inflammatory pharmacological agents, including cytokine inhibitors and signaling pathway blockers, have been developed recently, keeping the skin clean is of utmost importance in maintaining physiological cutaneous barrier function and avoiding an AD flare.

Benefits of the Topical JAK Inhibitor Delgocitinib in a Patient With Pediatric Localized Scleroderma.

This is the first report of pediatric linear scleroderma successfully treated with the topical Janus kinase (JAK) inhibitor delgocitinib. JAK inhibitors targeting the JAK/STAT pathway have been used to treat various immune-mediated diseases. In both in vitro and in vivo, JAK inhibitors also block the transforming growth factor (TGF)-β-mediated effects that contribute to skin sclerosis.

A Case of Basal Cell Carcinoma Exacerbated with Akatsuki Disease.

Akatsuki disease (also known as pomade crust) is characterized by skin lesions resulting from inadequate skin hygiene. It is sometimes influenced by underlying psychological factors. Akatsuki disease sometimes mimics cutaneous horn or skin cancer.

Leukomelanoderma Resembling Hyperpigmented Mycosis Fungoides.

Acquired circumscribed hyperpigmented patches and plaques have various differential diagnoses, including post-inflammatory hyperpigmentation and mycosis fungoides (MF). Leukomelanoderma is an uncommon cutaneous condition in which the pathogenesis is not fully elucidated. It has been reported that leukomelanoderma occurs after allergic contact dermatitis from hydroquinone or acute cutaneous graft-versus-host disease (1,2).

Involvement of cutavirus in a subset of patients with cutaneous T-cell lymphoma with an unfavorable outcome.

Background: European studies suggest an association between cutavirus (CuV) and cutaneous T-cell lymphoma (CTCL); however, the worldwide prevalence of CuV in patients with CTCL and its prognostic impact remain unknown.

Methods: We investigated the prevalence and viral loads of CuV DNA using biopsy specimens from the lesional skins of 141 Japanese patients with cutaneous malignancies, including 55 patients with various types of CTCL.

Results: CuV DNA was detected significantly more frequently in biopsies from patients with mycosis fungoides (MF) (38% [13/34]; the most common subtype of CTCL) than in those from patients with other cutaneous malignancies (6% [6/107]; P<0.

Primary Cutaneous Gamma-Delta T-Cell Lymphoma Initially Diagnosed as Subcutaneous Panniculitis-like T-Cell Lymphoma with Dermatomyositis.

Primary cutaneous gamma-delta T-cell lymphoma (CGD-TCL) is a rare cutaneous lymphoma. Panniculitis-like T-cell lymphoma (SPTCL) has a better prognosis than CGD-TCL. SPTCL is sometimes associated with autoimmune disease.

A Case of Nevoid Acanthosis Nigricans Successfully Treated with Topical Ketoconazole Plus Urea.

Dear Editor, Nevoid acanthosis nigricans (AN) is a rare form of benign AN that can be mostly found as a solitary lesion distributed along Blaschko's lines (1). It is not associated with any known syndrome, endocrinopathy, drugs, or internal malignancy. Treatments include retinoid, calcipotriol, and laser treatments (2).

What Are Reactive Oxygen Species, Free Radicals, and Oxidative Stress in Skin Diseases?

Oxygen in the atmosphere is a crucial component for life-sustaining aerobic respiration in humans. Approximately 95% of oxygen is consumed as energy and ultimately becomes water; however, the remaining 5% produces metabolites called activated oxygen or reactive oxygen species (ROS), which are extremely reactive. Skin, the largest organ in the human body, is exposed to air pollutants, including diesel exhaust fumes, ultraviolet rays, food, xenobiotics, drugs, and cosmetics, which promote the production of ROS.

Multiple roles of macrophage in skin.

More than 100 years have passed since Elie Metchnikoff discovered macrophage. Over the recent decade, attracting information about macrophage polarization have been reported. This is because many molecules have been identified as markers of macrophage polarization.

Durable response after discontinuation of pembrolizumab therapy for intrahepatic cholangiocarcinoma: a case report.

Although it has recently been reported that immune checkpoint inhibitors (ICIs) constitute effective treatment for solid tumors, the success rate in patients with intrahepatic cholangiocarcinoma is limited. We administered pembrolizumab to a patient as treatment for liver and lymph node metastases of intrahepatic cholangiocarcinoma. The patient had abundant infiltration of programmed death ligand 1-positive macrophages, cytotoxic T cells (CD8-positive lymphocytes), and programmed death 1-positive lymphocytes as well as a high combined positive score of 33.