Dermato, Volume 5, Issue 4 (December 2025) – 7 articles

Italian Court of Cassation Ruling Decree 30032 of 30 October 2023 discusses a medical malpractice case concerning the diagnosis of dermatofibrosarcoma protuberans and the alleged diagnostic and therapeutic delay. By examining how the ruling frames the role of histopathology in proving pathology benignity, authors prompt to reflect on diagnostic path, the allocation of the burden of proof, and the role of dermatologist’s expertise in professional liability issues. Over a four-year period, five health professionals were involved in a claim concerning an initial diagnosis of an epidermoid cyst and a subsequent diagnosis of dermatofibrosarcoma protuberans. The plaintiff questioned the delay in diagnosis, and the Court of Cassation found two physicians liable because they could not prove that the treated pathology was initially benign. We argue that equating diagnostic correctness exclusively with histological confirmation is unnecessary, both clinically and legally, in typical cases, if the reasoning and findings are adequately documented. Additionally, we examine the value of dermatologists’ experience and the scope of professional competence as measures of liability. Finally, we outline the minimum standards of clinical documentation necessary to make the diagnostic pathway traceable and verifiable. The diagnostic process is a discretionary effort that integrates multiple sources of information, both instrumental and experiential, to reach the most reasonable hypothesis. While histopathology is a crucial tool, it is not the sole gateway to a correct diagnosis of every cutaneous alteration. Adequate disclosure and structured documentation of the diagnostic reasoning are fundamental to the care process and fair assessment of professional responsibility. Full article

Immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 antibodies, have significantly improved outcomes in a variety of solid tumors, including urothelial carcinoma. However, their use is frequently associated with immune-related adverse events (irAEs) which frequently affect the skin and mucous membranes. Among these, plasma-cell-rich infiltrates are exceptionally rare. Circumorificial plasmacytosis (COP) is a rare, predominantly reactive condition typically involving mucosal transition zones, with histologic features characterized by dense, polyclonal plasma cell infiltrates and a benign clinical course. Only two case reports have described COP in association with ICI therapy and, to date, transformation or overlap with lymphoproliferative disorders such as marginal zone lymphoma has not been documented. We report the case of an 86-year-old male with urothelial carcinoma who developed a progressive, ulcerated, bleeding lesion of the lower lip during adjuvant nivolumab therapy. Histologic examination revealed a dense subepithelial infiltrate of mature plasma cells and lymphocytes. Direct and indirect immunofluorescence studies were negative, excluding autoimmune blistering disorders. Immunohistochemistry showed a predominance of CD138-positive plasma cells with a moderate kappa light-chain shift, CD19 expression, and absence of CD56, Cyclin-D1, and CD117, arguing against a plasma cell neoplasm. Molecular analysis via multiplex PCR revealed a clonal B-cell population with distinct IgH rearrangements, and some EBV-positive cells were also identified by EBER in situ hybridization. The histopathologic and molecular findings suggested a marginal zone lymphoma-like, plasmacytic proliferation arising in the setting of COP. This case illustrates a rare and diagnostically challenging constellation at the intersection of reactive and clonal B-cell proliferations in the context of ICI therapy. Although the lesion demonstrated features of clonality, the overall low B-cell content, indolent clinical course, and lack of systemic involvement support a reactive, immunodeficiency-associated lymphoproliferation rather than overt lymphoma. This case expands the known spectrum of mucocutaneous irAEs and highlights the need for careful clinicopathologic correlation, including immunophenotyping and molecular diagnostics. Awareness of such rare presentations is essential to avoid overdiagnosis and unnecessary systemic treatment in patients with otherwise indolent lesions. Full article

Linear atrophoderma of Moulin (LAM) is a rare, benign dermatosis characterized by unilateral, hyperpigmented, slightly atrophic plaques distributed along Blaschko’s lines. We report the case of an 18-year-old woman with a four-year history of asymptomatic lesions on the right abdomen, thigh, and foot. Histopathology revealed basal layer hyperpigmentation, mild collagen thickening, and a sparse perivascular lymphocytic infiltrate, without sclerosis. The clinical and histological findings confirmed the diagnosis of LAM. Given the stable course and absence of symptoms, a conservative approach with follow-up was adopted. This case underscores the importance of recognizing LAM’s distinctive presentation to avoid unnecessary treatments. Full article

The human skin microbiome, defined as a multifaceted ecosystem comprising bacteria, fungi, viruses, and mites, plays a pivotal role in maintaining skin homeostasis and regulating immune responses. In recent years, an increasing amount of evidence has illuminated the considerable influence exerted by microbiomes on the pathophysiology of dermatological ailments. This review provides a comprehensive synthesis of contemporary findings concerning the microbiome’s role in acne, aging, hyperpigmentation, and hair disorders, while also addressing the emerging concept of the gut–skin axis and how it could interfere in these skin disorders. Alterations in microbial composition, referred to as dysbiosis, have been associated with inflammatory processes and barrier dysfunction, thereby contributing to the severity and chronicity of diseases. Distinct microbial profiles have been identified as correlating with specific skin conditions. For instance, variations in Cutibacterium acnes phylotypes have been associated with the development of acne, whereas alterations in Corynebacterium and Staphylococcus species have been linked to the processes of aging and pigmentation patterns. Furthermore, the composition of the microbiome is examined in relation to its impact on cosmetic outcomes. It also engages with increasing interest in the modulation of microbiota through the topical application of bioactive compounds. The incorporation of prebiotics, probiotics, and postbiotics into cosmetic formulations constitutes a novel strategy aimed at enhancing skin health. In the domain of dermatological therapies, postbiotics have emerged as a significant class of substances, particularly due to their remarkable stability, safety, and immunomodulatory properties. These characteristics position them as promising candidates for incorporation into dermatological treatments. Recent studies have underscored the significance of microbiome-informed strategies within the domains of therapeutic and preventive dermatology, emphasizing the potential of such approaches to positively influence patient outcomes. As our understanding of this field continues to evolve, skin microbiomes are poised to emerge as a pivotal area of focus in the realm of personalized skin care and treatment. This development presents novel and innovative approaches for the management of skin conditions, characterized by enhanced specificity and efficacy. Full article

Background: The lipid components of the skin barrier have the strongest structure when arranged in an orthorhombic packing. This structure can be influenced by the external supply of lipophilic ingredients. While the benefits of ceramide supplementation are well-documented, the effects of the cosmetic formulation’s oil-based ingredients have been less explored. Methods: The packing structures of commonly used oil and wax ingredients in cosmetics were analyzed using FT-IR. These components were then combined to formulate a cosmetic composition with an orthorhombic packing structure. The strength of the skin barrier was assessed by measuring transepidermal water loss (TEWL), and the lipid packing of the porcine skin was analyzed using FT-IR. Results: In cosmetic oil ingredients, structurally simple oils such as mineral oil and squalane exhibited orthorhombic lipid packing, while more complex oils like isopropyl myristate (IPM) and isononyl isononanoate (ININ) showed hexagonal packing. Based on these structural characteristics, cosmetic formulations were designed by selectively combining oils, waxes, and emulsifiers to achieve a desired packing structure. Formulations incorporating orthorhombically packed oils successfully resulted in orthorhombic overall structures, whereas those including hexagonally packed oils tended to form hexagonal packing. The orthorhombic oils and formulation effectively maintained the structure and function of the porcine skin lipid barrier without disruption. Conclusions: This study demonstrated that orthorhombic oils and emulsions with orthorhombic packing effectively maintained skin barrier integrity, unlike hexagonal structures. Full article

Background: currently, there is a growing trend toward multifunctional cosmetics, which combine several active ingredients in a single product to enhance efficacy and user convenience. As ingredients may influence one another, it is important to study the behavior of mixing multiple compounds in complex formulations, especially regarding their interaction with the skin. Piceatannol, for instance, is a naturally occurring stilbene recognized for its in vitro potent antioxidant, anti-inflammatory, and anti-aging activities, making it a promising candidate for dermocosmetic use in suncare. But despite its beneficial biological activities, its cutaneous permeation remains poorly understood, particularly when delivered from complex formulations containing multiple ingredients. Objectives: in this sense, this study aimed to evaluate the in vitro skin diffusion profile of piceatannol from a passion fruit seed extract (P_ext) incorporated into a topical base (B_em) or an organic sunscreen emulsion (O_em), with or without a spilanthol-rich Acmella oleracea extract (J_ext) used as a natural permeation enhancer. Methods: due to ethical and variability issues with human and animal skins, the Strat-M™ synthetic membrane was chosen as a standardized model for the in vitro skin permeation assays. Piceatannol localization within membrane layers was examined by confocal Raman microscopy (CRM), while compound identification in donor and receptor compartments was performed via UHPLC-DAD. Results: piceatannol from B_em was detected up to 140 µm from the Strat-M™ surface and exceeded 180 µm in depth when J_ext and organic sunscreens were included in the formulation. Notably, formulations containing J_ext and those based on O_em promoted enhanced accumulation in both the stratum corneum and deeper skin layers, suggesting an improved delivery potential in lipid-rich vehicles. Conclusions: even though some instability issues were observed, piceatannol penetration into Strat-M™ from the proposed formulations was confirmed, and the results provide a foundation for further research on its topical delivery, supporting the rational development of formulations capable of harnessing its demonstrated biological properties. Full article

Cutaneous leiomyosarcoma is a rare, malignant tumor that arises from smooth muscle cells, accounting for less than 3% of all cutaneous sarcomas. Our case report details a 63-year-old male patient who presented with a rapidly growing, painful nodule in the popliteal region. The patient underwent initial surgical excision in September 2021, followed by three subsequent resections until March 2022 due to local recurrence. Histopathological analysis of all specimens revealed a dermal neoplasm composed of spindle cells arranged in intersecting fascicles with storiform patterns. The immunohistochemistry profile showed strong positivity for the markers SMA and desmin, confirming the diagnosis. Despite early interventions, the deep surgical margins were positive, and further surgeries were required until tumor-free margins were achieved. This case emphasizes the morphological characteristics, clinical behavior, and therapeutic challenges in managing cutaneous leiomyosarcoma. A favorable prognosis is achieved with long-term follow-up and a multidisciplinary approach. Full article