Search Results (59)

Background: Undifferentiated pleomorphic sarcoma (UPS) is a rare, high-grade soft-tissue sarcoma characterized by a patternless proliferation of bizarre pleomorphic tumor cells lacking identifiable lineage differentiation. Its occurrence in the oral cavity is exceptionally uncommon and poses significant diagnostic challenges due to its morphological overlap with a wide spectrum of other malignancies. Material and Methods: We report a novel case of oral UPS in a 54-year-old woman, characterized by an exceptionally large size and a rapidly progressive clinical course. The diagnostic evaluation included clinical, radiological, histopathological, immunohistochemical, and molecular analyses conducted within a multidisciplinary framework. A comprehensive review of the literature on oral UPS was also performed. Results: The patient underwent an aggressive demolitive surgical approach due to the extent of the lesion. Molecular analysis revealed a previously unreported SPECC1L::TERT gene fusion. The literature review highlighted the rarity of oral UPS, its geographic predilection for Central and East Asia, possible associations with traumatic events, and its heterogeneous clinical and histopathological presentations. Conclusions: This case underscores the critical importance of a thorough diagnostic workup to ensure the accurate diagnosis and appropriate management of this rare and aggressive tumor. Multidisciplinary evaluation is essential, especially in anatomically complex and diagnostically challenging presentations such as oral UPS. Full article

Artificial intelligence (AI) is rapidly transforming diagnostic approaches in different fields of medical sciences, demonstrating an emerging potential to revolutionize dermatopathology due to its capacity to process large amounts of data in the shortest possible time, both for diagnosis and research purposes. Different AI models have been applied to neoplastic skin diseases, especially melanoma. However, to date, very few studies have investigated the role of AI in dermatoses. Herein, we provide an overview of the key aspects of AI and its functioning, focusing on medical applications. Then, we summarize all the existing English-language literature about AI applications in the field of non-neoplastic skin diseases: superficial perivascular dermatitis, psoriasis, fungal infections, onychomycosis, immunohistochemical characterization of inflammatory dermatoses, and differential diagnosis between the latter and mycosis fungoides (MF). Finally, we discuss the main challenges related to AI implementation in pathology. Full article

Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities. Despite morphological and immunophenotypic similarities to melanoma, CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation. This genetic signature is absent in melanoma, making molecular diagnosis essential for accurate differentiation. Additionally, recent evidence highlights the utility of PRAME as an immunohistochemical marker to distinguish CCS from melanoma and other neoplasms. Clinically, CCS commonly involves tendons and aponeuroses, with metastatic potential leading to poor prognoses despite optimal local disease management. Histologically, CCS features lobular growth, spindle-to-epithelioid cells with clear cytoplasm, and low mitotic activity, often necessitating a multimodal diagnostic approach incorporating histopathology, immunohistochemistry, and molecular testing. Therapeutically, wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging. Adjuvant radiotherapy is considered in select cases, while chemotherapy has limited efficacy in metastatic settings. Emerging treatments, including targeted therapies focusing on EWSR1-ATF1-driven pathways and immune checkpoint inhibitors, offer hope for improved outcomes. This review synthesizes current knowledge on CCS, emphasizing diagnostic challenges, the role of PRAME, and advancements in therapeutic strategies to enhance patient care. Full article

Cutaneous squamomelanocytic tumor (SMT) is a very rare cutaneous malignancy, composed of a dual phenotypic population of both malignant melanocytes and keratinocytes, intimately intermingled together. Herein, we report a new case of a SMT occurring in an 82-year-old man, located on the scalp. Histopathology revealed a mixed population consisting of squamous cell carcinoma and melanoma within the same lesion, also confirmed using immunohistochemical staining for high molecular-weight cytokeratins (HMWCKs) and Melan-A. Moreover, to the best of our knowledge, for the first time, we tested SMT for the preferentially expressed antigen in melanoma (PRAME), which revealed a strong and diffuse positivity in the melanocytic component. These tumors need to be distinguished by more frequent collision tumors and colonization. Furthermore, we provide a comprehensive review of the literature, focusing on clinical and histopathological aspects, biological behavior and still-debated, but fascinating histogenesis of this elusive entity. Full article

A cutaneous carcinosarcoma (cCS) is a rare and aggressive skin cancer characterized by both carcinomatous (epithelial) and sarcomatous (mesenchymal) components, making it a biphasic tumor. Despite its occurrence in various organs, a cCS is exceptionally rare in the skin, predominantly affecting older males. The etiology of a cCS is unclear, but it may originate from a single progenitor cell capable of dual differentiation or from a collision of carcinoma and sarcoma cells. Clinically, a cCS presents as a rapidly growing, painful, ulcerated nodule or plaque on sun-exposed skin, with a high risk of local invasion and metastasis. Histopathologically, a cCS includes various epithelial components, such as squamous cell carcinoma and basal cell carcinoma, along with undifferentiated sarcomatous components resembling atypical fibroxanthoma. The tumor may also exhibit heterologous differentiation like angiosarcomatous or rhabdomyosarcomatous features. We present three cases of a cCS, highlighting their clinical and histological characteristics and comparing them with previously reported cases. Understanding a cCS is complicated by its rarity and diverse presentation, emphasizing the need for further research to elucidate its pathogenesis and optimal management. Full article

In recent years, particular interest has developed in molecular biology applied to the field of dermatopathology, with a focus on nevi of the Spitz spectrum. From 2014 onwards, an increasing number of papers have been published to classify, stratify, and correctly frame molecular alterations, including kinase fusions. In this paper, we try to synthesize the knowledge gained in this area so far. In December 2023, we searched Medline and Scopus for case reports and case series, narrative and systematic reviews, meta-analyses, observational studies—either longitudinal or historical, case series, and case reports published in English in the last 15 years using the keywords spitzoid neoplasms, kinase fusions, ALK, ROS1, NTRK (1-2-3), MET, RET, MAP3K8, and RAF1. ALK-rearranged Spitz tumors and ROS-1-rearranged tumors are among the most studied and characterized entities in the literature, in an attempt (although not always successful) to correlate histopathological features with the probable molecular driver alteration. NTRK-, RET-, and MET-rearranged Spitz tumors present another studied and characterized entity, with several rearrangements described but as of yet incomplete information about their prognostic significance. Furthermore, although rarer, rearrangements of serine–threonine kinases such as BRAF, RAF1, and MAP3K8 have also been described, but more cases with more detailed information about possible histopathological alterations, mechanisms of etiopathogenesis, and also prognosis are needed. The knowledge of molecular drivers is of great interest in the field of melanocytic diagnostics, and it is important to consider that in addition to immunohistochemistry, molecular techniques such as FISH, PCR, and/or NGS are essential to confirm and classify the different patterns of mutation. Future studies with large case series and molecular sequencing techniques are needed to allow for a more complete and comprehensive understanding of the role of fusion kinases in the spitzoid tumor family. Full article

Blastic Plasmacytoid Dendritic Cell Neoplasms (BPDCNs) are a rare, highly aggressive hematological malignant neoplasm that primarily involve the skin, bone marrow, lymph nodes and even extra-nodal sites. The rarity and relative poor description of cases in the literature make it necessary to review and further studies that deeply investigate this entity not only in a histopathological but also molecular field. In August–September 2023, we searched MEDLINE, PubMed and Scopus for randomized controlled trials (RCTs), narrative and systematic reviews, meta-analyses, observational studies (either longitudinal or retrospective), and case series published in English in the last 25 years using the keywords BPDCN, PDCs, Blastic NK-cell lymphoma, agranular CD4+ NK leukemia/lymphoma, agranular CD4+ CD56+ hematodermic neoplasm/tumor. Despite the progress made in recent years in the diagnosis and biological understanding of the disease, until 2018 there was no clear consensus regarding its treatment and the main therapeutic schemes used were based on chemotherapy regimens already used in the treatment of lymphomas, acute lymphoblastic leukemia (ALL) and/or acute myeloid leukemia (AML). In this narrative review, we address the definition and epidemiological features of BPDCN, provide the different theories on the etiopathogenesis with particular attention to the presumed cell of origin, discuss the main clinical manifestations that provide a sign of its presence, summarize the main histopathological and immunophenotypic characteristics with special attention to the most important markers, and finally, we provide some of the most effective information on the therapeutic treatment modalities of BPDCN. Full article

Lymphoepithelioma-like carcinoma of the skin (LELCS) is a rare primary skin cancer, with an annual incidence of 1/100,000 and about 85 cases published in the literature. It is considered the cutaneous counterpart of undifferentiated nasopharyngeal carcinoma (UNC, Schmincke–Regaud tumor) but has no association with EBV. We present an interesting case with features of LELCS in a 93-year-old man, right frontal–orbital region, diagnosed histologically and with immunohistochemical features. We also emphasize contrasting morphologic features for correct nosographic classification and address current issues, suggesting potential insights. Finally, we briefly reviewed other cases described in the literature. Full article

(1) Background: Endocrine Mucin-Producing Sweat Gland Carcinoma (EMPSGC) is a rare, low-grade, neuroendocrine-differentiated, cutaneous adnexal tumor, officially recognized by the World Health Organization (WHO) Skin Tumors Classification in 2018 as a separate entity and homologue of endocrine ductal carcinoma in situ (eDCIS)/solid papillary carcinoma of the breast. Although it is more frequent in the female sex, between 60 and 70 years old, in the peri-orbital region, EMPSGC has also been described in the male sex, in subjects under 60 and over 80, and in extra-eyelid localizations (cheek, temple, scalp), but also in extra-facial localizations (chest and scrotum). (2) Methods: We present the clinical case of a 71-year-old woman with an undated lesion of the scalp, which presented as a nodule, skin-colored, and 2.5 cm in maximum diameter. We also conduct a comprehensive literature review from 1997 to the end of 2022, consulting PubMed, Scopus, Web of Science (WoS), and Google Scholar using the following keywords: “Endocrine mucin-producing sweat gland carcinoma” and/or “EMPSGC” and/or “skin” and “cutaneous neoplasms”. In addition, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 253 patients were recorded; 146 were females (57.7%) and 107 were males (42.2%). The vast majority of the lesions were in the eyelids (peri-ocular region), and only a minority of cases involved the cheeks, supra-auricular, retro-auricular, and occipital region, with very rare cases in the scalp, to which the present is also added. (4) Conclusions: The morphological and immunophenotypical features are essential both for the correct diagnosis and to be able to classify this lesion among the corresponding eDCIS/solid papillary carcinoma of the breast, with neuroendocrine differentiation. Recent papers have attempted to shed light on the molecular features of EMPSGC, and much remains to be conducted in the attempt to subtype the molecular profiles of these entities. Future studies with large case series, and especially with molecular biology techniques, will be needed to further add information about EMPSGC and its relationship in the PCMC spectrum. Full article

Malignant melanoma (MM) is the “great mime” of dermatopathology, and it can present such rare variants that even the most experienced pathologist might miss or misdiagnose them. Naevoid melanoma (NM), which accounts for about 1% of all MM cases, is a constant challenge, and when it is not diagnosed in a timely manner, it can even lead to death. In recent years, artificial intelligence has revolutionised much of what has been achieved in the biomedical field, and what once seemed distant is now almost incorporated into the diagnostic therapeutic flow chart. In this paper, we present the results of a machine learning approach that applies a fast random forest (FRF) algorithm to a cohort of naevoid melanomas in an attempt to understand if and how this approach could be incorporated into the business process modelling and notation (BPMN) approach. The FRF algorithm provides an innovative approach to formulating a clinical protocol oriented toward reducing the risk of NM misdiagnosis. The work provides the methodology to integrate FRF into a mapped clinical process. Full article

Programmed death-ligand 1 (PD-L1) is the primary ligand of the receptor programmed death-1 (PD-1) which is constitutively expressed or activated in myeloid, lymphoid (T, B and NK), normal epithelial cells, and cancer. The PD-1/PD-L1 interaction is crucial for the physiological development of immunological tolerance but also in the development of the cancer. Among these, malignant melanoma represents a tumour in which the immunohistochemical expression of PD-L1 is important to guide future therapeutic choices based on the presence/absence of expression. Various clones have been used over time for immunohistochemical determination, and different results and heterogeneity remain among the various studies in the literature. We perform a narrative review of the present studies in order to discuss and take stock of what certain achievements have been made in this field, what challenges remain, and what possible solutions can be found. Full article

Various adverse reactions to SARS-CoV-2 vaccines have been described since the first months of the vaccination campaign. In addition to more frequent reactions, rare reactions, such as sarcoidosis-like, rashes have been reported. We present a case of a 23-year-old woman with a rash on the chin and peribuccal region, which developed approximately 3 weeks after the administration of the second dose of the Moderna mRNA-1273 vaccine. We briefly discuss other reports in the literature. Full article

Traditionally, the term melanoma in situ (MIS) is used to designate a horizontal (radial) growth phase of malignant melanoma (MM) in which there is no histological evidence of any invasion (or microinvasion) of neoplastic melanocytic cells into the superficial or papillary dermis. In daily dermatopathological practice, we are faced with misleading definitions, such as “melanoma in situ with regression,” which risk affecting homogeneity for comparison purposes of pathological reports of malignant melanoma. The authors conducted a literature review using PubMed and Web of Science (WoS) as the main databases and using the following keywords: “Malignant Melanoma in situ” or “Melanoma in situ” and “regression” and/or “radial growth phase regression.” A total of 213 articles from both analyzed databases were retrieved; finally, only eight articles in English were considered suitable for the chosen inclusion criteria. In consideration of the absence of studies with large case series, of reviews with meta-analyses, and, therefore, of a broad scientific consensus, expressions including “melanoma in situ with regression” should be avoided in the histopathological report. Instead, they should be replaced with clearer and more exhaustive definitions. Full article

T cell immunoglobulin and mucin domain 3 (TIM-3) is an inhibitory immunocheckpoint that belongs to the TIM gene family. Monney et al. first discovered it about 20 years ago and linked it to some autoimmune diseases; subsequent studies have revealed that some tumours, including melanoma, have the capacity to produce inhibitory ligands that bind to these receptor checkpoints on tumour-specific immune cells. We conducted a literature search using PubMed, Web of Science (WoS), Scopus, Google Scholar, and Cochrane, searching for the following keywords: “T cell immunoglobulin and mucin-domain containing-3”, “TIM-3” and/or “Immunocheckpoint inhibitors” in combination with “malignant melanoma” or “human malignant melanoma” or “cutaneous melanoma”. The literature search initially turned up 117 documents, 23 of which were duplicates. After verifying eligibility and inclusion criteria, 17 publications were ultimately included. A growing body of scientific evidence considers TIM-3 a valid inhibitory immuno-checkpoint with a very interesting potential in the field of melanoma. However, other recent studies have discovered new roles for TIM-3 that seem almost to contradict previous findings in this regard. All this demonstrates how common and valid the concept of ‘pleiotropism’ is in the TME field, in that the same molecule can behave completely or partially differently depending on the cell type considered or on temporary conditions. Further studies, large case series, and a special focus on the immunophenotype of TIM-3 are absolutely necessary in order to explore this highly promising topic in the near future. Full article