Primary cutaneous lymphomas are a heterogeneous group of T- and B-cell lymphomas that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. The 2005 World Health ...Organization–European Organization for Research and Treatment of Cancer (WHO-EORTC) consensus classification has served as a golden standard for the diagnosis and classification of these conditions. In September 2018, an updated version of the WHO-EORTC was published in the fourth edition of the WHO Classification of Skin Tumours Blue Book. In this classification, primary cutaneous acral CD8+ T-cell lymphoma and Epstein-Barr virus positive (EBV+) mucocutaneous ulcer are included as new provisional entities, and a new section on cutaneous forms of chronic active EBV disease has been added. The term “primary cutaneous CD4+ small/medium T-cell lymphoma” was modified to “primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder” because of its indolent clinical behavior and uncertain malignant potential. Modifications have also been made in the sections on lymphomatoid papulosis, increasing the spectrum of histologic and genetic types, and primary cutaneous marginal zone lymphomas recognizing 2 different subtypes. Herein, the characteristic features of these new and modified entities as well as the results of recent molecular studies with diagnostic, prognostic, and/or therapeutic significance for the different types of primary cutaneous lymphomas are reviewed. An update of the frequency and survival of the different types of primary cutaneous lymphomas is provided.
Abstract Primary cutaneous lymphomas represent a broad group of diseases with different clinical, histopathological, phenotypic, molecular, and prognostic features. All cutaneous lymphomas share the ...same tropism of neoplastic lymphocytes for the skin, but precise classification is paramount for proper management of the patients. Primary cutaneous lymphomas are classified according to the schemes proposed by the European Organization for Research and Treatment of Cancer (EORTC)-Cutaneous Lymphomas Task Force together with the World Health Organization (WHO) in 2005, and the WHO classification of 2008 with the 2016 update. The recognition of organ-based lymphomas, including cutaneous lymphomas, reflects a shift in the approach to lymphoproliferative disorders, and represents one of the major advances in the WHO classification of hematological tumors. Future studies should be aimed at shedding light on the many grey areas of cutaneous lymphomas (particularly the diagnosis and nomenclature of early mycosis fungoides and variants), and at gathering more data on the disorders that are still listed as provisional entities in the WHO classification.
Merkel cell carcinoma: A review Walsh, Noreen M.; Cerroni, Lorenzo
Journal of cutaneous pathology,
March 2021, Letnik:
48, Številka:
3
Journal Article
Recenzirano
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Merkel cell carcinoma has been a focus of active scientific investigation in recent years and new information on the topic has emerged. Although uncommon, this primary cutaneous neuroendocrine ...carcinoma, usually involving the head/neck of elderly individuals, has a poor prognosis. Within the past two decades, an increase in the incidence of the tumor and the discovery of its link to the Merkel cell polyomavirus have focused medical attention on the lesion. The resulting studies have improved our understanding of the biology of the neoplasm and contributed to clinical care. Specifically, two pathogenic subsets of the tumor have come to light, the majority due to Merkel cell polyomavirus and the minority caused by ultraviolet radiation‐induced genetic damage. This dichotomy carries prognostic implications favoring the former subset. In addition, having capitalized on the known susceptibility of the tumor to immune influences, investigators have recently discovered its responsiveness to immune checkpoint inhibition. This revelation has constituted a therapeutic milestone at the clinical level. Herein we provide an overview of the topic, outline updates in the field and place an emphasis on dermatopathologic aspects of Merkel cell carcinoma.
Adverse reactions to injectable soft tissue fillers Requena, Luis, MD; Requena, Celia, MD; Christensen, Lise, MD ...
Journal of the American Academy of Dermatology,
01/2011, Letnik:
64, Številka:
1
Journal Article
Recenzirano
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In recent years, injections with filler agents are often used for wrinkle-treatment and soft tissue augmentation by dermatologists and plastic surgeons. Unfortunately, the ideal filler has not yet ...been discovered and all of them may induce adverse reactions. Quickly biodegradable or resorbable agents may induce severe complications, but they will normally disappear spontaneously in a few months. Slowly biodegradable or nonresorbable fillers may give rise to severe reactions that show little or no tendency to spontaneous improvement. They may appear several years after the injection, when the patient does not remember which product was injected, and treatment is often insufficient. In this review, we discuss the most commonly used fillers, their most frequent adverse reactions as well as the characteristic histopathologic findings that allow the identification of the injected filler agent. In conclusion, histopathologic study remains as the gold standard technique to identify the responsible filler. Learning objectives After completing this learning activity, participants should be able to recognize the most frequent adverse reactions induced by cosmetic fillers, identify their histopathologic characteristics so that they can be distinguished from each other, and advise their patients with adverse reactions about the different nature of these according to the filler for subsequent successful treatment.
We recently reported that germline mutations in BAP1 cause a familial tumor syndrome characterized by high penetrance for melanocytic tumors with distinct clinical and histologic features. ...Melanocytic neoplasms in affected individuals harbored BRAF mutations, showed loss of BAP1 expression, and histologically resembled so-called "atypical Spitz tumors" (ASTs). ASTs are an ill-defined and probably heterogenous group of melanocytic tumors that display histologic features seen in both Spitz nevi and melanomas. Their biological behavior cannot be reliably predicted. In view of the histologic similarities of the familial tumors and ASTs, we hypothesized that a subset of ASTs might harbor genetic alterations seen in the familial tumors. To address this hypothesis, we analyzed 32 sporadic ASTs for BRAF mutations and for BAP1 expression. Nine (28%) sporadic ASTs showed loss of BAP1 expression, of which 8 (89%) had concomitant BRAF mutations. Only 1 of the BAP1-positive ASTs (4%) had a BRAF mutation (P<0.0001). BRAF-mutated, BAP1-negative tumors were primarily located in the dermis and were composed entirely or predominantly of epithelioid melanocytes with abundant amphophilic cytoplasm and well-defined cytoplasmic borders. Nuclei were commonly vesicular and exhibited substantial pleomorphism and conspicuous nucleoli. The combination of BRAF mutation and loss of nuclear BAP1 expression thus characterizes a subset of ASTs with distinct histologic features. The typical morphology of these tumors and BAP1 immunohistochemistry provide pathologic clues that will enable accurate identification of this subset. Future studies are necessary to determine whether this subset has a predictable clinical behavior.
Common acquired melanocytic nevi are benign neoplasms that are composed of small, uniform melanocytes and are typically present as flat or slightly elevated pigmented lesions on the skin. We describe ...two families with a new autosomal dominant syndrome characterized by multiple, skin-colored, elevated melanocytic tumors. In contrast to common acquired nevi, the melanocytic neoplasms in affected family members ranged histopathologically from epithelioid nevi to atypical melanocytic proliferations that showed overlapping features with melanoma. Some affected individuals developed uveal or cutaneous melanomas. Segregating with this phenotype, we found inactivating germline mutations of BAP1, which encodes a ubiquitin carboxy-terminal hydrolase. The majority of melanocytic neoplasms lost the remaining wild-type allele of BAP1 by various somatic alterations. In addition, we found BAP1 mutations in a subset of sporadic melanocytic neoplasms showing histological similarities to the familial tumors. These findings suggest that loss of BAP1 is associated with a clinically and morphologically distinct type of melanocytic neoplasm.
Deep penetrating nevus (DPN) is characterized by enlarged, pigmented melanocytes that extend through the dermis. DPN can be difficult to distinguish from melanoma but rarely displays aggressive ...biological behavior. Here, we identify a combination of mutations of the β-catenin and mitogen-activated protein kinase pathways as characteristic of DPN. Mutations of the β-catenin pathway change the phenotype of a common nevus with BRAF mutation into that of DPN, with increased pigmentation, cell volume and nuclear cyclin D1 levels. Our results suggest that constitutive β-catenin pathway activation promotes tumorigenesis by overriding dependencies on the microenvironment that constrain proliferation of common nevi. In melanoma that arose from DPN we find additional oncogenic alterations. We identify DPN as an intermediate stage in the step-wise progression from nevus to melanoma. In summary, we delineate specific genetic alterations and their sequential order, information that can assist in the diagnostic classification and grading of these distinctive neoplasms.Deep penetrating nevi (DPN) are unusual melanocytic neoplasms with unknown genetic drivers. Here the authors show that majority of DPN harbor activating mutations in the β-catenin and the MAP-kinase pathways; this characteristic can help in the classification and grading of these distinctive neoplasms.
Primary cutaneous CD30+ lymphoproliferative disorders (CD30+ LPDs) are the second most common form of cutaneous T-cell lymphomas and include lymphomatoid papulosis and primary cutaneous anaplastic ...large-cell lymphoma. Despite the anaplastic cytomorphology of tumor cells that suggest an aggressive course, CD30+ LPDs are characterized by an excellent prognosis. Although a broad spectrum of therapeutic strategies has been reported, these have been limited mostly to small retrospective cohort series or case reports, and only very few prospective controlled or multicenter studies have been performed, which results in a low level of evidence for most therapies. The response rates to treatment, recurrence rates, and outcome have not been analyzed in a systematic review. Moreover, international guidelines for staging and treatment of CD30+ LPDs have not yet been presented. Based on a literature analysis and discussions, recommendations were elaborated by a multidisciplinary expert panel of the Cutaneous Lymphoma Task Force of the European Organization for Research and Treatment of Cancer, the International Society for Cutaneous Lymphomas, and the United States Cutaneous Lymphoma Consortium. The recommendations represent the state-of-the-art management of CD30+ LPDs and include definitions for clinical endpoints as well as response criteria for future clinical trials in CD30+ LPDs.
Occlusive Nonvasculitic Vasculopathy Llamas-Velasco, Mar; Alegría, Victoria; Santos-Briz, Ángel ...
The American journal of dermatopathology
39, Številka:
9
Journal Article
Recenzirano
We review the most characteristic clinical and histopathologic findings of the cutaneous manifestations of the occlusive nonvasculitic vasculopathic disorders. Clinically, most of these conditions ...are characterized by retiform purpura. Histopathologic findings consist of occlusion of the vessel lumina with no vasculitis. Different disorders may produce nonvasculitic occlusive vasculopathy in cutaneous blood and lymphatic vessels, including embolization due to cholesterol and oxalate emboli, cutaneous intravascular metastasis from visceral malignancies, atrial myxomas, intravascular angiosarcoma, intralymphatic histiocytosis, intravascular lymphomas, endocarditis, crystal globulin vasculopathy, hypereosinophilic syndrome, and foreign material. Other times, the occlusive disorder is due to platelet pugging, including heparin necrosis, thrombocytosis secondary to myeloproliferative disorders, paroxysmal nocturnal hemoglobinuria, and thrombotic thrombocytopenic purpura. Occlusive vasculopathy may also appear in cold-related gelling agglutination, like that occurring in cryofibrinogenemia, cryoglobulinemia, cold agglutinin syndrome, and crystalglobulinemia. Microorganisms may also occlude the vessels lumina and this is especially frequent in ecthyma gangrenosum, opportunistic fungi as aspergillosis or fusariosis, Lucio phenomenon of lepromatous leprosy and disseminated strongyloidiasis. Systemic coagulopathies due to defects of C and S proteins, coumarin/warfarin-induced skin necrosis, disseminated intravascular coagulation, and antiphospholipid antibody/lupus anticoagulant syndrome may also result in occlusive nonvasculitic vasculopathy. Finally, vascular coagulopathies such as Sneddon syndrome, livedoid vasculopathy, and atrophic papulosis may also cause occlusion of the vessels of the dermis and/or subcutis. Histopathologic study of occlusive vasculopathic lesions is the first step to achieve an accurate diagnosis, and they should be correlated with clinical history, physical examination, and laboratory findings to reach a final diagnosis.
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