Most Recent

Background: Inherited ichthyoses are a heterogeneous group of disorders of cornification caused by mutations in genes encoding epidermal proteins. Clinically, patients with ichthyosis present with erythema, scaling, and occasionally blistering; some...

Rheumatoid nodules are the most common extra-articular manifestation of rheumatoid arthritis. Long-term immunomodulatory therapies, including corticosteroids, used in the management of rheumatoid arthritis are associated with a higher risk of infecti...

Background: Behçet-like syndrome (BLS) refers to the presence of Behçet’s disease (BD) features occurring in association with distinct clinical–pathological conditions such as inborn errors of immunity, myeloproliferative di...

Cutaneous squamous cell carcinoma (cSCC) is an immunogenic malignancy with variable immune infiltration and inconsistent responses to checkpoint blockade. Tumor-infiltrating lymphocytes (TILs) influence tumor progression and therapeutic outcome, yet...

Accurate diagnosis of melanomas is crucial for proper evaluation and treatment. One immunohistochemical stain frequently utilized is PRAME (PReferentially expressed Antigen in MElanoma), a tumor-associated antigen expressed in most melanomas. This st...

Reticulated acanthoma with sebaceous differentiation (RASD) is a rare, benign cutaneous neoplasm. Its variable clinical presentation frequently mimics both benign and malignant entities, posing a significant diagnostic challenge. We report a case of...

Abductive reasoning, or abduction, is a key process in scientific discovery and medical diagnosis. In everyday dermatology and dermatopathology, however, it functions as the practical engine behind differential diagnosis, clinicopathologic correlatio...

In this study we evaluated the expression of Angiopoietin 1, Angiopoietin 2, and Tie2 by immunohistochemistry in the skin of 10 patients with erythemato telangiectatic and papulopustular rosacea. Significantly increased expression of Tie2 and Angiopo...

Lentigo maligna (LM) is a melanoma in situ with high cumulative sun damage. Histological evaluation of resection margins is difficult and time-consuming. Melanocyte density (MD) is a suitable, quantifiable, and reproducible diagnostic criterion. In t...

Melanoma is a highly aggressive skin cancer primarily linked to ultraviolet (UV) radiation. However, the potential role of ionizing radiation from radiotherapy in melanoma development remains unclear. This review synthesizes data from epidemiologic s...

Melanoma subtyping plays a vital role in histopathological diagnosis, informing prognosis and, in some cases, guiding targeted therapy. However, conventional histologic classification is constrained by inter-rater reliability, morphologic overlap, an...

A 56-year-old patient presented to our dermatology clinic with asymmetric hyperpigmentation on her lower lip, which had developed over the previous six to twelve months. Her medical history included kidney and pancreas transplants, requiring chronic...

We report the case of a 16-year-old girl presenting with a painless, clinically stable subcutaneous swelling of the nasal dorsum with a three-year history. Despite an extensive multidisciplinary diagnostic work-up—including dermatological, otor...

Encephalocraniocutaneous lipomatosis (ECCL) is a rare congenital neurocutaneous disorder characterized by ocular, skin, and central nervous system manifestations. Despite its recognizable clinical features, such as nevus psiloliparus, histopathologic...

Background/Objectives: Oral focal mucinosis (OFM) and solitary cutaneous focal mucinosis (SCFM) are rare, benign lesions characterized by localized mucin deposition in the stromal connective tissue. While both share similar histological features, the...

Neurofibromatosis type 1 (NF1) is a prevalent neurocutaneous illness resulting from mutations in the NF1 gene, usually diagnosed according to clinical criteria set by the National Institutes of Health (NIH). These encompass café-au-lait macule...

Dermatofibromas (DFs) are benign neoplasms of the dermis typically found on the extremities of young adults. In approximately 3–5% of cases, basaloid cell hyperplasia (BCH) is observed overlying DFs. BCH is characterized by the proliferation of basal...

There are many benign skin neoplasms encountered in dermatopathology practice that can be associated with underlying genetic disorders. Although benign themselves, these lesions can offer insight into the potential for development of internal maligna...

Acroangiodermatitis is an uncommon angioproliferative dermatosis, related to chronic circulatory diseases, such as chronic venous insufficiency and arteriovenous malformations. We describe the case of a 32-year-old healthy male presenting with a prur...

Human herpesvirus-8 (HHV-8)-associated multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder with systemic and cutaneous manifestations that can be diagnostically challenging, especially in immunocompromised patients. We report...

A 27-year-old female with no significant medical or dermatologic history presented with a persistent acneiform eruption on the face. The patient had been treated with multiple topical and systemic anti-acne treatments with no significant improvement...

Despite therapeutic advancements, malignant melanoma remains a leading cause of skin cancer-related mortality, with incidence continuing to rise globally. Traditional prognostic tools offer important clinical guidance but fail to capture the biologic...

Stratum Corneum (SC) formation in the human epidermis requires lipid processing. Lipoxygenases (LOXs) such as 12R-Lipoxygenase (12R-LOX) and Epidermis-type lipoxygenase 3 (eLOX-3) contribute to this process. Mutations in their genes cause Autosomal R...

Introduction: Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma, often exhibiting loss of pan-T-cell markers such as CD2, CD3, CD5, and CD7. While these immunophenotypic alterations assist in diagnosis, their prognostic relevance in...

Dermatofibroma is a common mesenchymal skin lesion that typically presents as a firm, slow-growing nodule. Generally, such lesions are asymptomatic; however, they can also cause discomfort in some cases. Ulceration is an uncommon feature of dermatofi...

I have reviewed the insightful comments on my review article titled “Direct Immunofluorescence of Skin and Oral Mucosa: Guidelines for Selecting the Optimum Biopsy Site” [...]

Compilation written by Muhammad N [...]

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a complex immune response. Given the considerable heterogeneity of the clinical phenotype of HS, this study aimed to analyse the immunohistochemical pattern of interstit...

Pilomatricomas are benign tumors originating from hair follicle matrix cells and represent the most common skin tumors in pediatric patients. Pilomatricomas may be associated with genetic syndromes such as myotonic dystrophy, familial adenomatous pol...

Whether the spongiotic reaction caused by the interaction of keratinocytes, T-lymphocytes, inflammatory dendritic epidermal cells (IDECs), and Langerhans cells (LCs) observed in atopic dermatitis (AD) represents a common feature of spongiosis in vari...

In this review, we explore the complexities of objectively assessing the response to immunotherapy in mycosis fungoides (MF), a prevalent form of cutaneous T-cell lymphoma. The core challenge lies in distinguishing between reactive and malignant lymp...

A 29-year-old gentleman of African descent presented to the emergency department with a three month history of a rash affecting the trunk, upper limbs, and thighs. The patient was unsure of any triggers and denied any preceding illness, new medicatio...

Background: We present an interesting case involving a tumour comprising both basal cell tumour cells and sarcomatoid tumour cells. An 86-year-old woman presented with an erythematous lesion on her left cheek. Clinical and dermoscopic findings sugges...

Penile intraepithelial neoplasia (PeIN) is a rare but clinically significant condition that can progress to invasive squamous carcinoma. Early diagnosis is crucial but often challenging due to its heterogeneous clinical and dermoscopic presentation,...

Background: Diabetics accumulate Advanced Glycation End products (AGEs) such as Nε-(carboxymethyl)lysine (CML) in their skin, which can provoke changes in the skin’s biomechanical properties. The same changes are also observed during ag...

Psoriasis is a chronic immune-mediated inflammatory skin disorder characterized by keratinocyte hyperproliferation, impaired epidermal barrier function, and immune dysregulation. The Th17/IL-23 axis plays a central role in its pathogenesis, promoting...

A 71-year-old Caucasian woman presented with lesions on both elbows. A physical examination revealed arcuate plaques with raised erythematous edges and central clearing. Comedones and cysts were evident on the border of the lesions. The dermatoscopic...

A 64-year-old patient presented for management of symptomatic skin-colored papules symmetrically distributed over the lateral neck over the past two years, which failed to improve on multiple topical corticosteroids, antifungal creams, and topical ca...

Cutaneous metastases from internal organ cancers are diagnosed in approximately 0.2% of skin biopsies. This diagnosis can be the first sign of a previously undiagnosed malignancy with an internal organ origin. We conducted a retrospective study that...

Melasma is an incredibly common dyschromic disorder, mostly impacting women with skin of color. There are three variants of melasma based on the depth of pathologic involvement: epidermal, mixed, and dermal. While there are many treatments for melasm...

Congenital melanocytic nevi (CMN) are benign tumors present at birth or arising in the first few months of life. A small subset of these nevi present with mild atypical features and heterogeneous differentiation, including Schwannian differentiation....

Hydroxyurea (HU), a cornerstone treatment for myeloproliferative disorders, is associated with a wide range of cutaneous side effects, from xerosis and hyperpigmentation to more severe conditions like dermatomyositis-like eruptions (DM-LE) and nonmel...

Dermatofibromas (DFs) represent prevalent benign fibrohistiocytic tumors, typically manifesting as solitary lesions. In the majority of cases, the clinical presentation and dermoscopic and histopathological features of DFs adhere to a characteristic...

The Wolf isotopic response (WIR) refers to the development of cutaneous lesions in areas of previously healed but unrelated skin disease. While most are observed in healed herpes zoster, WIR has been reported in various other contexts. Affected areas...

Hypertrophic lichen planus (HLP) is a chronic inflammatory skin condition defined by verrucous, pruritic, papules and plaques usually affecting the lower limbs. The diagnosis of HLP is primarily clinical. However, due to its feasible generalized pres...

Kikuchi–Fujimoto disease (KFD) is a rare condition characterized by necrotizing lymphadenitis and fever, often associated with immune dysregulation. Histologically, it features necrotic foci with abundant histiocytes and plasmacytoid dendritic...

Based on histologic and genetic patterns, the current World Health Organization (WHO) classification distinguishes six subtypes of lymphomatoid papulosis (Lyp). The aim of our article was to analyze the frequency of histologic and immunohistochemical...

Hyperalgesic priming is a model of the transition from acute to chronic pain. Whether a similar mechanism exists for “pruritic priming” of itch is unknown. Here, we tested the hypothesis that itchy skin in a commonly used mouse model of d...

Cutaneous silica granulomas are a form of foreign-body granulomatous reactions. They are characterized histopathologically by sarcoidal granulomas in association with silica crystals. Asteroid bodies, a classical histopathological feature of sarcoido...

The diagnosis, interpretation, and classification of melanocytic tumors is a very complex topic in the pathology and dermatopathology field that lacks standardization and is still subject to discordance and debate. Here, we review the definitions of...