Dermatopathology最新文献

{"title":"Perineuriomatous Melanocytic Nevus: A Case Report of a Rare and Underreported Melanocytic Lesion.","authors":"Muhammad N Mahmood, Eunice Y Chow","doi":"10.3390/dermatopathology13020025","DOIUrl":"10.3390/dermatopathology13020025","url":null,"abstract":"<p><p>Melanocytic nevi exhibiting perineuriomatous differentiation are rare and pose significant diagnostic challenges due to their low incidence and morphological resemblance to other cutaneous spindle-cell lesions, including desmoplastic melanoma. In this report, we describe the clinical, dermoscopic, microscopic, and immunohistochemical features of a perineuriomatous melanocytic nevus on the right mid-forearm of a 73-year-old Caucasian man. Given the scarcity of reported cases, documenting additional examples is crucial for refining clinicopathological diagnostic criteria. Accurate identification relies on thorough histopathological and immunohistochemical assessment. By presenting the current case, we aim to enhance diagnostic accuracy and raise awareness of this uncommon nevus. A clearer understanding of these characteristics will help dermatologists and dermatopathologists identify this nevus and distinguish it from other cutaneous spindle-cell proliferations.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13298030/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148319826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cutaneous Hematologic Neoplasms in Children: Overview and Update.","authors":"Philippe Drabent, Anne Welfringer, Alejandro A Gru, Thierry J Molina, Sylvie Fraitag","doi":"10.3390/dermatopathology13020024","DOIUrl":"10.3390/dermatopathology13020024","url":null,"abstract":"<p><p>Cutaneous hematologic neoplasms in children are relatively rare and encompass a wide range of lymphoproliferative and myeloproliferative disorders. This review explores and updates the classification, clinical presentation, diagnostic challenges, histopathology, and management of pediatric lymphomas, lymphoproliferations, and leukemias that may be seen in the skin. The most frequent of them are lymphomatoid papulosis (LyP) and mycosis fungoides (MF), and are discussed first, with a particular focus on differential diagnosis and overlaps with benign lesions-mainly pityriasis lichenoides-which raises questions regarding the delineation of these entities and their potential interconnection. It is important to underline that most cutaneous lymphoproliferations are indolent in children: primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder, subcutaneous panniculitis-like T-cell lymphoproliferation (non-associated with <i>HAVCR2</i> mutations), primary cutaneous marginal zone lymphoproliferative disorder, and EBV-related lymphoproliferative disorders. However, aggressive hematologic malignancies, although rarer, must not be missed; these are mostly leukemias (but not all forms) and blastic plasmacytoid dendritic cell neoplasm. We emphasize the importance of clinical-pathological correlation, with clonality studies playing a crucial role in some cases. Management strategies are briefly reviewed, ranging from skin-directed therapies like phototherapy and corticosteroids to systemic treatments for more aggressive forms of leukemia cutis and lymphomas.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13297799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148319863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inflammatory and Infectious Cutaneous Entities Resembling Cutaneous T-Cell Lymphoma (CTCL): An Integrated Clinicopathological Review.","authors":"Jade Nasser Eldin, Elias El Tayar, Ossama Abbas, Jag Bhawan","doi":"10.3390/dermatopathology13020023","DOIUrl":"10.3390/dermatopathology13020023","url":null,"abstract":"<p><p>Cutaneous pseudolymphomas are benign reactive lymphoid proliferations that often mimic cutaneous lymphomas both clinically and histologically. A diverse array of inflammatory, infectious, and drug-induced dermatoses can closely resemble cutaneous T-cell lymphomas (CTCLs), particularly mycosis fungoides (MFs), posing significant diagnostic challenges. These mimickers may show histopathological features such as epidermotropism, dense lymphocytic infiltrates, or even clonality, making accurate differentiation crucial to avoid overtreatment. This review endeavors to comprehensively discuss the clinicopathologic features of the various inflammatory and infectious dermatoses that may simulate CTCL, drawing on illustrative examples across disease categories. By highlighting important comparative features and emphasizing the importance of clinicopathologic correlation, this review outlines practical strategies for distinguishing true lymphoma from its inflammatory mimics.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13298085/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148319858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Cutaneous Immune Microenvironment in Selected Inflammatory Skin Diseases: Linking Histopathology, Mechanisms, and Targeted Therapy.","authors":"Andreea Cătălina Tinca, Andreea Raluca Cozac-Szoke, Ovidiu Simion Cotoi","doi":"10.3390/dermatopathology13020022","DOIUrl":"10.3390/dermatopathology13020022","url":null,"abstract":"<p><p>Inflammatory skin diseases are characterized by complex interactions between immune pathways, epidermal barrier function, and environmental triggers, leading to distinct clinical and histopathological features. This narrative review aims to integrate current knowledge on the cutaneous immune microenvironment across major inflammatory skin diseases, including atopic dermatitis, psoriasis, hidradenitis suppurativa, and vitiligo. A comprehensive literature search was conducted using PubMed, Web of Science, and Scopus, focusing on studies published between 2021 and early 2026. The findings highlight disease-specific immune signatures, such as Th2-driven inflammation in atopic dermatitis, IL-23/Th17 axis activation in psoriasis, neutrophil-dominated responses in hidradenitis suppurativa, and cytotoxic T-cell-mediated melanocyte destruction in vitiligo. These molecular pathways are closely reflected in histopathological patterns, emphasizing the link between morphology and immunopathogenesis. Advances in targeted therapies, including biologics and Janus kinase inhibitors, demonstrate the clinical relevance of these pathways and support a transition toward mechanism-based treatment strategies. Dermatopathology is increasingly contributing to precision medicine approaches by supporting correlations between tissue features, immune pathways, and potential therapeutic targets. This review provides a framework for improved disease stratification and for the development of personalized treatment strategies in inflammatory skin diseases.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13214635/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148036298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Cazzato et al. Skin Mycetoma in an 11-Year-Old African Boy: Case Presentation with Emphasis on Histopathological Features and Differential Diagnosis. <i>Dermatopathology</i> 2021, <i>8</i>, 509-514.","authors":"Gerardo Cazzato, Anna Colagrande, Antonietta Cimmino, Lucia Lospalluti, Aurora Demarco, Caterina Foti, Paolo Romita, Francesca Arezzo, Vera Loizzi, Paola Parente, Leonardo Resta, Giuseppe Ingravallo","doi":"10.3390/dermatopathology13020021","DOIUrl":"10.3390/dermatopathology13020021","url":null,"abstract":"<p><p>The authors would like to make the following corrections to this published paper [...].</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13214926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148036285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Binary Positivity: Spectrum of Nodal Tumor Burden in Sentinel Lymph Node Biopsy for High-Risk Cutaneous Squamous Cell Carcinoma.","authors":"Irena Janković, Goran Stevanović, Toma Kovačević, Dimitrije Janković, Dimitrije Pavlović","doi":"10.3390/dermatopathology13020020","DOIUrl":"10.3390/dermatopathology13020020","url":null,"abstract":"<p><p><b>Background and Objectives</b>: Sentinel lymph node biopsy (SLNB) is increasingly used for high-risk, clinically node-negative cutaneous squamous cell carcinoma (cSCC), yet pathological reporting remains binary, lacking morphological stratification. The prognostic relevance of nodal tumor burden subtypes-isolated tumor cells (ITC), micrometastases, and macrometastases-is well established in melanoma and breast cancer but remains uncharacterized in cSCC. We aimed to describe the morphological spectrum of sentinel lymph node involvement in a consecutive institutional cohort and determine whether primary tumor characteristics predict the extent of nodal colonization. <b>Materials and Methods</b>: We conducted a retrospective-observational study at Clinical Center Niš (Serbia) including 35 consecutive clinically N0 high-risk cSCC patients who underwent SLNB using a dual-tracer protocol (⁹⁹mTc-labeled albumin and methylene blue). Sentinel nodes were processed by serial sectioning with hematoxylin-eosin and pancytokeratin (AE1/AE3) immunohistochemistry. Deposits were classified as ITC (≤0.2 mm), micrometastases (>0.2-2.0 mm), or macrometastases (>2.0 mm). Clinicopathologic predictors were evaluated using the Mann-Whitney U test, Fisher's exact test, the Kruskal-Wallis test, and the Spearman rank correlation test. <b>Results</b>: SLN involvement was identified in 12 of 35 patients (34.3%). Among positive cases, ITC accounted for 6 patients (50.0%), micrometastases for 5 (41.7%), and macrometastasis for 1 (8.3%)-minimal nodal disease constituting 91.7% of positive findings. No primary tumor feature-including diameter, thickness, grade, perineural invasion, or lesion multiplicity-significantly distinguished ITC from overt metastatic deposits. Patients with ITC showed numerically higher median tumor thickness (8.0 mm) than those with micrometastases (4.0 mm), though this did not reach significance (Kruskal-Wallis <i>p</i> = 0.065). <b>Conclusions</b>: SLN positivity in high-risk cSCC is morphologically heterogeneous, with minimal nodal disease predominating. Primary tumor features do not reliably stratify the extent of nodal colonization. Structured tumor-burden reporting-distinguishing ITC, micrometastases, and macrometastases-should be adopted as standard practice to enable meaningful prognostic comparisons and inform individualized management.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13214969/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148036360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudolymphomatous Granuloma Annulare Rich in B Lymphocytes.","authors":"Angel Fernandez-Flores, José Luis Martínez-Amo","doi":"10.3390/dermatopathology13020019","DOIUrl":"10.3390/dermatopathology13020019","url":null,"abstract":"<p><p>Granuloma annulare is a non-infectious granulomatous dermatosis with a probable pathogenic mechanism of delayed-type hypersensitivity, in which the dermal histiocytic granulomatous infiltrate is usually accompanied by a lesser component of lymphocytes. Although there are more common clinical and histopathological patterns of presentation, there are less well-known variants that may pose significant diagnostic challenges by mimicking other inflammatory cutaneous processes or even neoplastic conditions. One of the rarest forms of granuloma annulare is the pseudolymphomatous variant, in which the lymphocytic component is not only highly prominent but may, in some cases, partially or completely obscure the histiocytic component itself. This feature, together with the fact that the clinical presentation of this variant is often atypical-frequently lacking the characteristic annular morphology of conventional granuloma annulare-renders the diagnosis particularly challenging. From an immunohistochemical standpoint, the infiltrates described are predominantly composed of T cells, with only a sparse and scattered B-cell component. In this article, we present a case of granuloma annulare with a pseudolymphomatous B-cell component (PAX5⁺, CD79⁺) and minimal T-cell involvement, observed in a 4 mm skin nodule located on the shoulder of a 48-year-old male. This case therefore broadens the concept of pseudolymphomatous granuloma annulare to include infiltrates predominantly composed of B lymphocytes.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13214772/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148036342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pedunculated Acral Keratotic Papule on an Ischemic Foot.","authors":"Janmesh D Patel, Pooja A Shet, Sara E Dahle, Joshua M Schulman, Marat D Kazak","doi":"10.3390/dermatopathology13020018","DOIUrl":"10.3390/dermatopathology13020018","url":null,"abstract":"<p><p>An 86-year-old man presented with a slowly enlarging, subject to chronic mechanical irritation, pedunculated keratotic papule on the plantar tip of the right hallux in the setting of severe peripheral arterial disease. Excision was deferred until after endovascular revascularization to reduce the risk of nonhealing and limb complications, after which the lesion was removed without wound sequelae. Histopathology demonstrated a conical papule with a central collagenous core and an overlying cap of compact hyperkeratosis. This case highlights key clinicopathologic features that distinguish acral keratotic tumors and underscores the importance of perfusion optimization when planning elective excision on an ischemic limb.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13108059/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Desmosomal-Type Acantholysis-A New Histologic Pattern Related to Mutations of Genes for Desmosomal Proteins.","authors":"Dieter Metze, Kira Süßmuth, Clemens Metze, Vinzenz Oji, Heiko Traupe","doi":"10.3390/dermatopathology13020017","DOIUrl":"10.3390/dermatopathology13020017","url":null,"abstract":"<p><p>Desmosomes are specialized cell-cell junctions that play a crucial role in maintaining the structural integrity of both cornifying and non-cornifying epithelium. Disruption of desmosomal cohesion in autoimmune, infectious, and other diseases is typically associated with acantholysis, often leading to intraepidermal blisters and erosions. In recent decades, genetic mutations have been identified that impair desmosomal integrity to varying degrees, giving rise to a spectrum of genodermatoses. These conditions, which include palmoplantar keratoderma, epidermolysis bullosa, and ichthyoses, can range from mild to severe, with some forms being syndromic and life-threatening. We investigated dermatopathologic changes in patients with mutations in genes encoding desmosomal proteins seen in consultations at our genodermatoses unit. A series of cases, including keratosis palmoplantaris areata et striata (striated palmoplantar keratoderma type 1), Carvajal-Huerta syndrome, severe dermatitis-multiple allergies-metabolic wasting (SAM) syndrome, ectodermal dysplasia-skin fragility syndrome, and inflammatory peeling skin disease, was examined histologically and, when necessary, immunohistochemically. Findings from our cohort were compared with histopathological consultation cases from our dermatopathology laboratory and previously published cases in the literature. Through these observations, we defined a distinct form of acantholysis associated with desmosomal protein mutations, which we term \"desmosomal-type acantholysis.\" We outline the spectrum of this newly characterized pattern and highlight its differences from conventional forms of acantholysis. Furthermore, for the first time, we describe incidental cases where \"desmosomal-type acantholysis\" appears sporadically in solitary acanthoma and in association with a melanocytic nevus.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13108170/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bilateral Auricular Blastomycosis-like Pyoderma: A Rare Presentation Histologically Misinterpreted as Squamous Cell Carcinoma.","authors":"Nazario Pesce, Giorgia Di Marco, Giorgio Stabile, Antonio Podo Brunetti, Alessandro Russo, Stefania Guida, Rongioletti Franco","doi":"10.3390/dermatopathology13020016","DOIUrl":"10.3390/dermatopathology13020016","url":null,"abstract":"<p><p>Blastomycosis-like pyoderma (BLP) is a rare chronic inflammatory dermatosis characterized by exuberant vegetative and verrucous plaques, most frequently associated with bacterial colonization, particularly <i>Staphylococcus aureus</i>. Owing to its striking clinical and histopathological resemblance to squamous cell carcinoma (SCC) and other granulomatous or hyperplastic dermatoses, BLP represents a well-recognized diagnostic pitfall, often leading to delayed diagnosis or unnecessary surgical management. We report an unusual case of bilateral auricular BLP in a 58-year-old apparently immunocompetent woman, initially misdiagnosed as SCC. Comprehensive clinicopathological reassessment revealed pseudoepitheliomatous hyperplasia, intraepidermal neutrophilic microabscesses, and a dense mixed inflammatory infiltrate, findings consistent with a reactive rather than neoplastic process. Microbiological cultures confirmed <i>Staphylococcus aureus</i>, supporting the final diagnosis of BLP and guiding effective antimicrobial therapy. To better contextualize this rare presentation, we reviewed all previously reported cases of BLP, summarizing available clinical, histopathological, microbiological, and therapeutic data. This case further raises the possibility of an association between BLP and systemic inflammatory conditions, as the patient subsequently developed severe colitis, highlighting the potential role of immune dysregulation and the gut-skin axis in disease pathogenesis or a possible temporal association, without allowing causal inference. Beyond inflammatory bowel disease, blastomycosis-like pyoderma has been reported in association with a variety of systemic and immune-mediated conditions, including diabetes mellitus, hematologic malignancies, HIV infection, chronic renal failure, autoimmune disorders, and prolonged immunosuppressive therapies. These associations support the concept that BLP represents a hyperinflammatory reaction pattern occurring in the setting of altered immune surveillance rather than a purely infectious disease. Accurate recognition and management of BLP require careful integration of clinical features, histological findings, and microbiological results. Increased awareness of its diverse presentations is essential to avoid misdiagnosis and to ensure appropriate, conservative treatment.</p>","PeriodicalId":42885,"journal":{"name":"Dermatopathology","volume":"13 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13108177/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}