Search Results (219)

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 polyposis (FAP), Turner syndrome, Rubinstein–Taybi syndrome, Kabuki syndrome, and Sotos syndrome. This study reviews the literature on pilomatricomas occurring in syndromic contexts and presents a novel case linked to Apert syndrome. A systematic review was conducted using PubMed and Cochrane databases, focusing on case reports, case series, and reviews describing pilomatricomas associated with syndromes. A total of 1272 articles were initially screened; after removing duplicates and excluding articles without syndromic diagnoses or lacking sufficient data, 81 full-text articles were reviewed. Overall, 96 cases of pilomatricomas associated with genetic syndromes were identified. Reports of patients with Apert syndrome who do not develop pilomatricomas are absent in the literature. Pilomatricomas predominantly affect pediatric patients, with a slight female predominance, and are often the first manifestation of underlying genetic syndromes. Our study highlights previously unreported associations of pilomatricoma with Apert syndrome, providing molecular insights. This study contributes to understanding the clinical and molecular features of pilomatricomas in syndromic contexts and underscores the importance of genetic analysis for accurate diagnosis and management. Full article

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 various skin diseases remains unclear. We analyzed the characteristics of spongiosis in AD compared with those in other eczematous dermatitis and inflammatory skin diseases by using immunohistochemical methods. Infiltration of IDECs (CD11c+ cells and/or CD206+ cells) and T-lymphocytes, accompanied by degenerated keratinocytes and aggregated LCs (CD207+ cells), was frequently observed as a common feature of spongiosis in multiple conditions. However, IDECs expressing IgE were identified exclusively in IgE-mediated AD. Aggregation of IDECs was predominantly observed in the spongiosis of adaptive immune-mediated eczematous disorders, such as AD and allergic contact dermatitis. These IDEC aggregations constituted the major components of the epidermal dendritic cell clusters seen in AD and other eczematous or eczematoid dermatoses, and may serve as a useful distinguishing marker from Pautrier collections seen in cutaneous T-cell lymphoma. These findings suggest that IDECs, in cooperation with other immune cells, may play a pivotal role in spongiosis formation in AD and various skin diseases, although the underlying immunopathological mechanisms differ among these conditions. Full article

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 lymphocytes amidst treatment, particularly given the absence of uniform pathological biomarkers for MF. We highlight the vital role of emerging histological technologies, such as multispectral imaging and spatial transcriptomics, in offering a more profound insight into the tumor microenvironment (TME) and its dynamic response to immunomodulatory therapies. Drawing on parallels with melanoma—another immunogenic skin cancer—our review suggests that methodologies and insights from melanoma could be instrumental in refining the approach to MF. We specifically focus on the prognostic implications of various TME cell types, including CD8+ tumor-infiltrating lymphocytes, natural killer (NK) cells, and histiocytes, in predicting therapy responses. The review culminates in a discussion about adapting and evolving treatment response quantification strategies from melanoma research to the distinct context of MF, advocating for the implementation of novel techniques like high-throughput T-cell receptor gene rearrangement analysis. This exploration underscores the urgent need for continued innovation and standardization in evaluating responses to immunotherapies in MF, a field rapidly evolving with new therapeutic strategies. Full article

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 medications, illicit drug use, or recent vaccinations. On examination, there was a widespread papulosquamous eruption characterised by scaly, hyperpigmented papules and plaques involving the trunk, upper arms, and upper thighs. A definitive diagnosis was established through a diagnostic skin biopsy of a fresh lesion. Full article

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 suggested BCC. Complete excision and histopathological examination revealed a BCC with a separate proliferation of atypical spindle and epithelioid cells. Immunohistochemical staining supported the diagnosis, with basaloid cells positive for CK5/6 and Ber-EP4 and sarcomatoid cells positive for CD10 and vimentin. Results: Histology and immunohistochemistry confirmed a basal cell carcinoma with sarcomatoid differentiation. The close proximity of sarcomatoid cells to the BCC component suggests a potential role of epithelial–mesenchymal interactions in tumour development. Further investigations into the exact origin of this tumour are required. Conclusion: Basal cell carcinoma with sarcomatoid differentiation is rare. This case highlights the importance of thorough histological and immunohistochemical evaluation. Further studies are necessary to better understand the pathogenesis of such collision tumours. Full article

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, which can mimic other benign or malignant lesions. In this study, we report two cases of pigmented penile lesions evaluated using non-invasive imaging techniques: reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT). Both methods revealed characteristic features such as hyperkeratosis, parakeratosis, acanthosis, nuclear pleomorphism of keratinocytes, and the presence of bright intraepithelial dendritic cells, correlating closely with histopathological findings of high-grade basaloid PeIN. Our findings highlight the valuable role of RCM and LC-OCT in improving the differential diagnosis of genital lesions, potentially reducing the need for invasive diagnostic procedures and ensuring early, appropriate management. Full article

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 aging. Collagen is one of the first targets of glycation, and this leads to the disruption of the dermis, potentially contributing to the skin complications seen in diabetes, like impaired wound healing and the formation of chronic ulcers. We therefore investigated whether it was possible to detect differences in the biomechanical properties of the reticular dermis by comparing C57/BL6 control mice, type 1 and type 2 diabetic mice, and aged mice. Methods: To investigate this, we used an Atomic Force Microscope (a type of local probe microscope used to visualize the surface topography of a sample) to measure the elastic modulus of each skin sample. The elastic modulus is a parameter that describes a tissue’s resistance to elastic deformation when stress is applied. We also determined whether diabetes is associated with the accumulation of AGEs via Western blots. Results: We found that type 2 diabetic mice and aged mice had a stiffer reticular dermis than young control mice. No differences were found in type 1 diabetic mice. The results of the Western blot did not reveal any significant differences in the CML content in different types of mice, although a non-significant increase was found in type 2 diabetic and aged mice. We show that there is a significant positive correlation between the amount of CML in a mouse and the rigidity of its reticular dermis. Conclusions/interpretation: We have demonstrated that increased glycation in mouse skin is correlated with the biomechanical properties of that skin, which explains the wound healing defects diabetic patient’s experience. AFM is therefore a powerful technique that could be used to characterize the mechanical effects of treatments aimed at reducing the level of AGEs in the skin. Full article

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 the production of key pro-inflammatory cytokines such as IL-17, IL-23, and TNF-α, which sustain chronic inflammation and epidermal remodeling. Emerging evidence suggests that SARS-CoV-2 may trigger new-onset or exacerbate existing psoriasis, likely through viral protein-induced activation of toll-like receptors (TLR2 and TLR4). This leads to NF-κB activation, cytokine release, and enhanced Th17 responses, disrupting immune homeostasis. Erythrodermic psoriasis (EP), a rare and severe variant, presents with generalized erythema and desquamation, often accompanied by systemic complications, including infection, electrolyte imbalance, and hemodynamic instability. In a murine model of SARS-CoV-2 infection, we found notable cutaneous changes: dermal collagen deposition, hair follicle destruction, and subcutaneous adipose loss. Parallel findings were seen in a rare clinical case (only the third reported case) of EP in a patient with refractory psoriasis, who developed erythroderma after off-label initiation of dupilumab therapy. The patient’s histopathology closely mirrored the changes seen in the SARS-CoV-2 model. Histological evaluations also reveal similarities between psoriasis flare-ups following dupilumab treatment and cutaneous manifestations of COVID-19, suggesting a shared inflammatory pathway, potentially mediated by heightened type 1 and type 17 responses. This overlap raises the possibility of a latent connection between SARS-CoV-2 infection and increased psoriasis severity. Since the introduction of COVID-19 vaccines, sporadic cases of EP have been reported post-vaccination. Although rare, these events imply that vaccine-induced immune modulation may influence psoriasis activity. Our findings highlight a convergence of inflammatory mediators—including IL-1, IL-6, IL-17, TNF-α, TLRs, and NF-κB—across three triggers: SARS-CoV-2, vaccination, and dupilumab. Further mechanistic studies are essential to clarify these relationships and guide management in complex psoriasis cases. Full article

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 view showed the presence of pores, in addition to granuloma annulare changes. The biopsies showed changes according to granuloma annulare, but the granulomas were closely related to comedones and cysts. Furthermore, the presence of elastophagocytosis via multinucleated Langhans-type giant cells was evident. Verhoeff–van Gieson staining highlighted the transepithelial elimination of elastic fibers in the bottom of some cysts. The presence of comedones or cysts is exceptional in granuloma annulare. Only four similar cases have been reported. Although all previous cases showed lesions in sun-exposed areas over photodamaged skin, only our case showed transepithelial elimination of elastic fibers. Diabetes mellitus (DM) could play a role in the pathogenesis of this variant of actinic granuloma annulare, because most cases are associated with uncontrolled DM and the lesions improve after DM is controlled. Full article

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 calcineurin inhibitor. Histopathologic examination showed a regular epidermis with increased melanophages in the papillary dermis, without vacuolar degeneration of the basement membrane. Verhoeff Van Gieson stain highlighted a band-like zone of attenuated elastic fibers in the papillary dermis, while Von Kossa stain was negative for calcified fibers. PAS staining was negative for fungal organisms and Alcian blue showed no increase in dermal mucin. Full article

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 included all cases of cutaneous metastases diagnosed in our hospital. A total of 25 patients were identified (14 females and 11 males). The average age of the patients included was 62.3. The most common primary cancer site was the lung for male patients, while for female patients it was the breast. In seven of our cases, cutaneous metastases were the first sign of an internal organ cancer. Common sites for cutaneous metastases in our study involved the anterior thoracic wall, the abdomen, and the scalp. Our study aims to highlight the importance of recognizing the histopathology of metastatic tumors and differentiating them from primary skin neoplasms. Immunohistochemistry is a mandatory tool for differential diagnosis in all cases, especially for patients who do not have a history of neoplasia. Full article

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 melasma, there is a paucity of research on melasma treatments and their dermatopathological correlates. A scoping review was conducted of all human trials on melasma with histopathologic analysis, including 37 trials in the final analysis. Most studies were conducted on women with a Fitzpatrick skin type of III or greater. Strong histologic evidence supports the utilization of retinols/retinoids for epidermal melasma and microneedling for dermal melasma. There is a paucity of trials conducted on melasma utilizing histologic correlates, and fewer still that are comprehensive to include analyses on quality of life. Full article

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. We present a case of a 3-week-old with a 7 cm red/purple scalp nodule consistent with CMN with mild atypical heterogeneous areas. On histology, there were dermal nests of spindle cells in a fibrillar matrix, with increased vessels and clusters of small round melanocytes interspersed between collagen bundles and around adnexal structures. The lesion also exhibited rare pagetoid ascent of melanocytes as single cells and nests. Overall, these features were consistent with a CMN with nodular proliferative neurocristic cutaneous hamartoma (NCH) with a component of a compound mild atypical melanocytic proliferation. Next generation sequencing (NGS) identified a novel SH2B1::BRAF fusion. This case highlights the diagnostic challenges of heterogeneous differentiation within CMN in young children. Full article

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 nonmelanoma skin cancers (NMSC), particularly squamous cell carcinoma (SCC). In this review, we present a unique case of HU-induced DM-LE with histological evidence of keratinocyte dysplasia and p53 overexpression, followed by a systematic analysis of similar cases. Our findings reveal that the clinical presentation of DM-LE, while typically considered benign, shares clinical and histological features with hydroxyurea-associated squamous dysplasia (HUSD), a precancerous condition that may progress to SCC in chronically exposed patients. Key insights include the characteristic histopathological findings of DM-LE, the role of chronic HU therapy and UV-induced damage in promoting p53 overexpression, and the overlap between DM-LE and HUSD. Regular dermatologic monitoring, patient education on photoprotection, and the careful assessment of skin lesions in long-term HU users are essential for the early detection and prevention of malignancies. This review underscores the importance of distinguishing between DM-LE, HUSD, and SCC to optimize management and minimize risks associated with HU therapy. Full article

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 profile. However, DFs may exhibit atypical clinical presentations and, more commonly, histologic attributes, posing challenges in differential diagnosis. Both DFs and basal cell carcinomas (BCCs) are frequently encountered cutaneous lesions, each characterized by distinct clinical and dermoscopic features and microscopic morphology. The simultaneous occurrence of these two entities within the same lesion is rare. DFs have been documented to form collision tumors in conjunction with a spectrum of benign and malignant lesions, encompassing not only BCC but also balloon cell nevus, squamous cell carcinoma (SCC), and melanoma. Alterations in the epidermis overlaying a DF range from simple hyperplasia to the proliferation of basaloid cells. Accurate diagnosis, leading to the complete excision of the lesion, is contingent upon the recognition of dermoscopic criteria, precluding misinterpretation as a benign lesion. We present two cases of collision tumors comprising DF and BCC. This case report underscores the paramount importance of dermoscopy and adherence to dermoscopic criteria in the assessment of collision lesions and the diagnostic process related to cutaneous malignancies. Full article