Pleomorphic Dermal Sarcoma.

Pleomorphic dermal sarcoma (PDS) is a rare cutaneous/subcutaneous neoplasm of purported mesenchymal differentiation that exists along a clinicopathologic spectrum with atypical fibroxanthoma (AFX). While PDS and AFX share histopathologic and immunohistochemical features, PDS exhibits deeper tissue invasion and has a higher rate of metastasis and local recurrence than AFX. Given its aggressive clinical course, early recognition and clinical management of PDS are essential for optimizing patient outcomes. This review aims to provide a brief overview of the clinicopathologic and molecular features, prognosis, and treatment of PDS.

Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates.

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

Cutaneous malakoplakia arising on the ankle of a patient with pyoderma gangrenosum.

Malakoplakia is a rare chronic inflammatory condition that most commonly involves the urogenital tract. Cutaneous malakoplakia is extremely rare and many patients diagnosed with skin involvement are immunosuppressed. While the clinical presentation of cutaneous malakoplakia is variable, the histopathologic features are quite distinct and include sheets of closely packed dermal histiocytes with foamy-appearing cytoplasm and Michaelis-Gutmann bodies that are positive with certain immunohistochemical stains. While the exact pathogenesis of malakoplakia is unknown, it has been associated with certain bacterial infections. Treatment generally involves a combination of surgery and antimicrobial agents and/or modulation of immunosuppressant therapy if appropriate. Herein, the authors report a unique case of cutaneous malakoplakia arising in a patient on chronic immunosuppressive therapy for the management of pyoderma gangrenosum.

Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates.

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

Hypertrophic Lichen Planus: An Up-to-Date Review and Differential Diagnosis.

CONTEXT.­: Hypertrophic lichen planus (HLP) is a variant of lichen planus that can be difficult to diagnose based on histopathologic features alone. Thus, patient clinical history and clinicopathologic correlation are essential considerations to make the correct diagnosis. OBJECTIVE.­: To discuss the clinical and histologic presentation of HLP and provide a thorough review of commonly encountered mimickers in the differential diagnosis. DATA SOURCES.­: Data were derived from a literature review, personal clinical and research experiences, and a review of cases in the archives of a tertiary care referral center. CONCLUSIONS.­: In general, HLP involves the lower extremities and is characterized by thickened, scaly nodules and plaques that are often pruritic and chronic in nature. HLP affects both males and females and is most common in adults 50 to 75 years of age. Unlike conventional lichen planus, HLP tends to have eosinophils and classically displays a lymphocytic infiltrate most concentrated around the tips of rete ridges. The differential diagnosis for HLP is broad and encompasses numerous entities in many different categories, including premalignant and malignant neoplasms, reactive squamoproliferative tumors, benign epidermal neoplasms, connective tissue disease, autoimmune bullous disease, infection, and drug-related reactions. Therefore, a high index of suspicion must be maintained to avoid a misdiagnosis and potential inappropriate treatments.

Cutaneous vascular tumors: an updated review.

Cutaneous vascular tumors constitute a heterogeneous group of entities that share overlapping morphologic and immunohistochemical features, which can be diagnostically challenging for pathologists and dermatopathologists. Our understanding and knowledge of vascular neoplasms have improved over time, resulting in both a refinement of their classification by the International Society for the Study of Vascular Anomalies (ISSVA) and an improvement in the accurate diagnosis and clinical management of vascular neoplasms. This review article aims to summarize the updated clinical, histopathological, and immunohistochemical characteristics of cutaneous vascular tumors, as well as to highlight their associated genetic mutations. Such entities include infantile hemangioma, congenital hemangioma, tufted angioma, spindle cell hemangioma, epithelioid hemangioma, pyogenic granuloma, Kaposiform hemangioendothelioma, retiform hemangioendothelioma, pseudomyogenic hemangioendothelioma, Kaposi sarcoma, angiosarcoma, and epithelioid hemangioendothelioma.

Mesenchymal tumours with melanocytic expression: a potential pitfall in the differential diagnosis of malignant melanoma.

Mesenchymal tumours with melanocytic expression can pose a diagnostic challenge because they frequently demonstrate both morphological and immunohistochemical overlap with other cutaneous melanocytic neoplasms. Therefore, they present potential pathological pitfalls that may lead to a misdiagnosis of malignant melanoma. Mesenchymal neoplasms that closely mimic melanoma include malignant melanotic nerve sheath tumour (melanotic schwannoma), epithelioid schwannoma, malignant peripheral nerve sheath, cutaneous syncytial myoepithelioma, clear cell sarcoma of soft tissue, and perivascular epithelioid cell tumour. Awareness of these melanoma mimics is necessary for establishing the correct diagnosis so that the appropriate clinical management can be rendered to the patient. This in-depth review highlights key diagnostic features and molecular genetics and also discusses the differential diagnosis and treatment of mesenchymal tumours that exhibit melanocytic expression.

A Case of Primary Myelofibrosis With Transformation to Leukemia Cutis.

ABSTRACT: We report an extraordinary case of primary myelofibrosis with transformation to leukemia cutis. A 64-year-old Caucasian man with a history of JAK2-positive primary myelofibrosis presented with erythematous papulonodules on his right lower extremity. A punch biopsy revealed a normal epidermis with an underlying diffuse dermal infiltrate composed of medium-to-large-sized myeloid cells and leukocytes. Neoplastic cells were immunoreactive for LCA, CD34, CD61, CD117, and CD68 and negative for lysozyme, CD20, CD3, myeloperoxidase, and TdT. These findings were consistent with a diagnosis of leukemia cutis. A concurrent bone marrow biopsy demonstrated a markedly fibrotic, hypercellular marrow without a significant increase in blasts. With no morphologic evidence of bone marrow involvement by acute myeloid leukemia, our case suggests that the patient's primary myelofibrosis transformed to leukemia cutis. Our patient died 2 months after the onset of his skin nodules. Our case demonstrates that leukemia cutis should be included in the differential diagnosis for cutaneous nodular lesions in patients with a history of an advanced-stage hematological malignancy.

A genomic survey of sarcomas on sun-exposed skin reveals distinctive candidate drivers and potentially targetable mutations.

Sarcomas on photodamaged skin vary in prognosis and management, but can display overlapping microscopic and immunophenotypic features. Improved understanding of molecular alterations in these tumors may provide diagnostic and therapeutic insights. We characterized 111 cutaneous sarcomatoid malignancies and their counterparts, including primary cutaneous angiosarcoma (n = 7), atypical fibroxanthoma (AFX) (n = 21), pleomorphic dermal sarcoma (PDS) (n = 17), extracutaneous undifferentiated pleomorphic sarcoma (n = 8), cutaneous leiomyosarcoma (LMS) (n = 5), extracutaneous LMS (n = 9), sarcomatoid squamous cell carcinoma (spindle cell squamous cell carcinoma) (S-SCC) (n = 24), and conventional cutaneous squamous cell carcinoma (SCC) (n = 20), by next-generation sequencing (NGS) using the StrataNGS panel for copy number variations, mutations, and/or fusions in more than 60 cancer-related genes. TP53 mutations were highly recurrent in most groups. Angiosarcoma displayed previously reported MYC amplifications, as well as CCND1 gains. RB1 mutations were relatively restricted to cutaneous LMS. As previously reported, PIK3CA mutations occurred in AFX, whereas RAS activation was more frequent in PDS. CDKN2A mutations were recurrent in AFX and S-SCC, whereas PDS displayed frequent CDKN2A deletion. S-SCC displayed mutational similarity to conventional SCC. BRCA1/2 mutations were specific to tumors with disease progression. In a subset, we detected potential driver events novel to these tumor types: activating mutations in IDH2 (PDS), MAP2K1 (angiosarcoma, PDS), and JAK1 (S-SCC) and copy gains in FGFR1 (angiosarcoma, S-SCC), KIT (AFX), MET (PDS), and PDGFRA (PDS). Our findings confirm and expand the spectrum of known genomic aberrations, including potential targetable drivers, in cutaneous sarcomatoid malignancies. In addition, certain events are relatively specific to particular tumors within this differential diagnosis and hence might be diagnostically informative.

Social media trends in dermatology, dermatopathology, and pathology publications: The social construction of medical subdisciplines.

BACKGROUND: An increase in the number of publications on social media has paralleled the growth of social media use in the past decade. Our study examined the trends in these publications relating to the fields of dermatology, pathology, and dermatopathology. METHODS: PubMed was searched for relevant literature from 2009 to present, using the following key terms: "social media", "dermatology", "dermatopathology", and "pathology." Topics of articles, years of publication, countries of origin, and contributing journals were compiled and analyzed. RESULTS: A total of 99 publications was retrieved during the period between January 2009 and November 2019. Top publication years included 2019 (n = 21), 2018 (n = 24), 2017 (n = 20), and 2016 (n = 13). The most common topic areas noted were related to dissemination of information (n = 17; 17.2%), knowledge exchange for physicians (n = 16; 16.2%), and social networking (n = 15; 15.2%). CONCLUSION: The number of published articles on social media in these specialties has increased since 2009, signifying the widespread use of social media for professional networking, knowledge exchange, real-time communication with patients and colleagues, and patient care. Social media in the areas of dermatology, dermatopathology, and pathology has undergone social construction during the past decade because of changes in technology and ideologies surrounding the use of social media within medicine.

Pembrolizumab-Induced Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis in a Patient With Metastatic Cervical Squamous Cell Carcinoma: A Case Report.

We present a rare case of a pembrolizumab-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). A 55-year-old woman with a history of metastatic cervical squamous cell carcinoma presented with a widespread mucocutaneous rash. Seventeen days after receiving her first cycle of pembrolizumab, she presented with fever, difficulty breathing, watery eyes, and painful oral ulcers. Physical examination revealed widespread erythematous papules and papulovesicles involving the trunk, upper extremity, and lower extremity and hemorrhagic plaques on the lower lip and buccal mucosa. Biopsy confirmed a diagnosis of SJS/TEN. This case highlights the importance of awareness of SJS/TEN as a possible adverse reaction for patients receiving pembrolizumab, a medication increasingly being used to treat metastatic or unresectable malignancies.

A Rare Case of Lichen Planus-Like Atopic Dermatitis Involving the Hands.

Lichen planus-like atopic dermatitis clinically mimics lichen planus and can pose a diagnostic challenge. We report a case of a 55-year-old African American woman who developed intensely pruritic papules and plaques on bilateral hands. Histological examination demonstrated acute spongiotic dermatitis with lymphocyte exocytosis into the epidermis. Taken together, a diagnosis of lichen planus-like atopic dermatitis was made. This case serves to highlight that lichen planus-like atopic dermatitis can develop on hands and that it presents as spongiotic dermatitis with lymphocyte exocytosis into the epidermis. Correlating the clinical presentation with histopathological findings will assist in establishing the diagnosis and guiding appropriate management.

Murine models of melanoma.

Melanoma is an aggressive and highly metastatic skin cancer, carrying a poor prognosis with a median survival time of 5.3-10 months depending on the stage of disease. Research has advanced our understanding of the underlying pathology of melanoma and strategies to prevent and treat melanoma. Mouse models have been developed to elucidate the molecular, immunological, and cellular mechanisms contributing to proliferation and metastasis of melanoma. This review article aims to provide an overview of various types of murine melanoma models, including xenograft and syngeneic transplantation models, genetically modified models, ultraviolent radiation models, and chemically induced models, and discuss the advantages and limitations of each model.

Malignant melanoma with osteosarcomatous differentiation in a lymph node metastasis.

Osteocartilaginous differentiation in malignant melanoma is rare and can pose a diagnostic challenge. In previously reported cases, melanomas were predominantly located on acral and mucosal sites, with osteocartilaginous differentiation present in either primary or recurrent lesions. We report a case of a 52-year-old female with malignant melanoma located on the right upper back exhibiting osteosarcomatous differentiation only in the axillary lymph node metastasis. This case serves to highlight that the divergent differentiation can occur in lymph node metastases while being absent in the primary lesion. The patient's medical history, careful histological examination, and immunohistochemistry may be necessary for establishing the correct diagnosis.

Practice of Teledermatopathology: A Systematic Review.

INTRODUCTION: Teledermatopathology has the potential to revolutionize the practice of diagnosing skin diseases. This review provides an overview of the advantages, limitations, and future directions of teledermatopathology. METHODS: MEDLINE was searched via PubMed and Google Scholar databases for relevant articles published from 2012 to the present. Additional articles were also identified by hand-searching. RESULTS: A total of 2675 citations were identified in the initial search. Two thousand five hundred seventy-three were excluded based on duplicates and review of titles and abstracts. Eighty studies failed to meet the inclusion criteria, resulting in a total of 22 articles for analysis. Nine additional articles were hand-searched. CONCLUSIONS: Recent studies report that telepathology increases access to specialists, reduces interpretive errors and health care expenditures, improves the efficiency of workflow, and optimizes patient outcomes. It also facilitates international collaboration by widening global access to dermatopathology services and providing educational resources in underserved areas. However, the quality and regulations of digital slide imaging in teledermatopathology need to be improved.

Deep Vein Thrombosis and Pulmonary Embolism Considerations in Orthopedic Surgery.

Patients undergoing orthopedic surgery have an increased risk for deep venous thrombosis (DVT) and pulmonary embolism (PE). These complications are considered detrimental, as they cause major postoperative morbidity and mortality and lead to a substantial health care burden. Because of the high incidence and serious nature of these complications, it is essential for orthopedic surgeons to have a comprehensive knowledge of the risk factors, diagnosis, and treatment of acute DVT and PE. Perioperative management of orthopedic patients to prevent postoperative DVT and PE and optimize postoperative outcomes is also discussed in this review.

Cardiovascular Considerations for Joint Replacement Surgery.

Heart disease is the leading cause of death in the United States. Cardiovascular complications are associated with higher morbidity and mortality rates for patients who undergo orthopaedic surgery. Therefore, the clinical importance of a comprehensive preoperative evaluation and medical clearance is crucial and may substantially improve postoperative outcomes. A thorough knowledge of cardiovascular perioperative planning and management can enable healthcare professionals to identify patients who are potentially at risk for cardiovascular complications, and eventually improve both short- and long-term patient outcomes and satisfaction.

Perioperative Treatment of Patients with Rheumatoid Arthritis.

Rheumatoid arthritis is an autoimmune disease mediated by a widespread, chronic, and systematic inflammatory process that causes joint deterioration, which leads to pain, disability, and poor quality of life. The increased use of disease-modifying antirheumatic drugs has been shown to markedly slow disease progression, which has translated into a decrease in the need for orthopaedic intervention in this population. However, in a substantial percentage of patients with the disease, optimal pharmacologic treatment fails and surgical intervention is required. A thorough understanding of medical considerations in these patients and improved knowledge of the medical complications caused by the disease process and the pharmacologic therapy used to treat it may lead to improved preoperative planning and medical clearance, which may ultimately improve the overall postoperative outcome.