Interobserver Variability in the Histopathological Evaluation of Melanoma: Analysis of 60 Cases.

INTRODUCTION: Since the field of dermatopathology is not an exact science, it is subject to personal subjectivity, which sometimes causes disagreements on the diagnosis and assessment of some histological features. In the case of melanoma, some variables such as regression are associated with low interobserver agreement. On the contrary, other variables such as the measurement of Breslow thickness show high reproducibility. OBJECTIVE: The main objective of our study was to investigate multiple features of 60 consecutive cases of melanoma to establish interobserver reproducibility. METHODS AND MAIN RESULTS: We conducted an observational and descriptive study at Hospital de Manises, Valencia, Spain, IVO Foundation, Valencia, Spain, and Hospital 12 de Octubre, Madrid, Spain. The mean level of agreement of all study variables was moderate (Cohen's kappa coefficient statistic=0.5). The highest agreement corresponded to polypoid morphology, pigmentation, ulceration, and solar elastosis. On the other hand, the lowest level agreement was reached for the presence of cellular pleomorphism and tumor necrosis. CONCLUSIONS: Our mean level of agreement was moderate, which reflects that some of the measured characteristics such as cellular pleomorphism or the presence of necrosis cannot be used for future studies or must be redefined and their reproducibility, reestablished. When conducting a research study, it is necessary to analyze the study variables to demonstrate their validity to measure or classify a certain feature. It is also advisable to warrant that that the variables are reproducible to be able to use them for other studies or in the routine clinical practice.

Different Mutational Profiles of Subcutaneous Panniculitis-like T-cell Lymphoma and Lupus Panniculitis: An Additional Case Series.

BACKGROUND: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cytotoxic T-cell lymphoma with indolent behavior, mostly present in women and associated with immunological diseases whose pathogenic background is still poorly understood. SPTCL is associated with lupus erythematosus panniculitis (LEP) and histologically misdiagnosed. OBJECTIVES: The aim of our study was to identify mutations affecting the pathogenesis of both SPTCL and LEP. MATERIALS AND METHODS: We studied a total of 10 SPTCL and 10 LEP patients using targeted next-generation sequencing and pyrosequencing. Differences in gene expression between molecular subgroups were investigated using NanoString technology. Clinical data were collected, and correlations sought with the molecular data obtained. RESULTS: The mutational profile of SPTCL and LEP is different. We identified fewer pathogenic mutations than previously reported in SPTCL, noting a single HAVCR2-mutated SPTCL case. Interestingly, 40% of our SPTCL cases showed the pathogenic TP53 (p.Pro72Arg) (P72R) variant. Although cases showing HAVCR2 mutations or the TP53 (P72R) variant had more severe symptomatic disease, none developed hemophagocytic syndrome (HPS). Furthermore, TP53 (P72R)-positive cases were characterized by a lower metabolic signaling pathway and higher levels of CD28 expression and Treg signaling genes. In addition, 30% of our cases featured the same mutation (T735C) of the epigenetic modificatory gene DNMT3A. None of the LEP cases showed mutations in any of the studied genes. CONCLUSIONS: The mutational landscape of SPTCL is broader than previously anticipated. We describe, for the first time, the involvement of the TP53 (P72R) pathogenic variant in this subgroup of tumors, consider the possible role of different genetic backgrounds in the development of SPTCL, and conclude that LEP does not follow the same pathogenic pathway as SPTCL.

Granulomas in Dermatopathology: Principal Diagnoses - Part 2. / Granulomas en dermatopatología: principales entidades. Parte II.

Part 2 of this series on granulomatous diseases focuses on skin biopsy findings. Whereas the first part treated noninfectious conditions (metabolic disorders and tumors, among other conditions), this part mainly deals with various types of infectious disease along with other conditions seen fairly often by clinical dermatologists.

Granulomas in Dermatopathology: Principal Diagnoses - Part 1. / Granulomas en dermatopatología: principales entidades. Parte I.

This series of 2 articles on dermatopathologic diagnoses reviews conditions in which granulomas form. Part 1 clarifies concepts, discusses the presentation of different types of granulomas and giant cells, and considers a large variety of noninfectious diseases. Some granulomatous diseases have a metabolic origin, as in necrobiosis lipoidica. Others, such as granulomatous mycosis fungoides, are related to lymphomas. Still others, such as rosacea, are so common that dermatologists see them nearly daily in clinical practice.

Clinical and Histopathologic Characteristics of the Main Causes of Vascular Occusion - Part II: Coagulation Disorders, Emboli, and Other. / Dermatopatología de la oclusión intraluminal vascular: parteII (coagulopatías, émbolos y miscelánea).

Vascular occlusion has multiple, diverse clinical manifestations, some of which can have grave consequences for patients. It also has a wide variety of causes, including thrombi, which we recently addressed in partI of this review. In this second part, we look at additional causes of vascular occlusion.

Primary cutaneous peripheral T-cell lymphoma, not otherwise specified: results of a multicentre European Organization for Research and Treatment of Cancer (EORTC) cutaneous lymphoma taskforce study on the clinico-pathological and prognostic features.

BACKGROUND: Cutaneous peripheral T-cell lymphoma, not otherwise specified (PTL NOS) is an aggressive, but poorly characterized neoplasm. OBJECTIVES: The European Organization for Research and Treatment of Cancer cutaneous lymphoma taskforce (EORTC CLTF) investigated 33 biopsies of 30 patients with primary cutaneous PTL NOS to analyse their clinical, histological, immunophenotypic features and outcome. METHODS: Retrospective analysis of clinical data and histopathological features by an expert panel. RESULTS: Cutaneous PTL NOS manifested clinically either with solitary or disseminated rapidly grown ulcerated tumours or disseminated papulo-nodular lesions. Histologically, a mostly diffuse or nodular infiltrate in the dermis and often extending into the subcutis was found. Epidermotropism was rarely present and only mild and focal. Unusual phenotypes were frequent, e.g. CD3+ /CD4- /CD8- and CD3+ /CD4+ /CD8+ . Moreover, 18% of the cases exhibited an aberrant expression of the B-cell marker CD20 by the tumour cells. All solitary tumours were located on the limbs and presented a high expression of GATA-3 but this did not correlate with outcome and therefore could not serve as a prognostic factor. The prognosis was shown to be generally poor with 10 of 30 patients (33%) dying of lymphoma within the follow-up of 36 months (mean value; range 3-144). The survival rates were 61% after 3 years (CI, 43-85%) and 54% after 5 years (CI, 36-81%). Small to medium-sized morphology of tumour cells was associated with a better outcome than medium to large or large tumour cells. Age, gender, clinical stage, CD4/CD8 phenotype and GATA-3 expression were not associated with prognosis. Chemotherapy was the most common treatment modality, but surgical excision and/or radiotherapy may represent an appropriate first-line treatment for solitary lesions. CONCLUSIONS: Cutaneous PTL NOS shows an aggressive course in most patients independent of initial presentation, age and phenotype. Cytomorphology was identified as a prognostic factor. The data indicate a need for more effective treatment modalities in PTL NOS.

Protocol for the Histologic Diagnosis of Cutaneous Melanoma: Consensus Statement of the Spanish Society of Pathology and the Spanish Academy of Dermatology and Venereology (AEDV) for the National Cutaneous Melanoma Registry. / Protocolo de diagnóstico histológico para muestras de pacientes con melanoma cutáneo. Documento de consenso de la SEAP y la AEDV para el Registro Nacional de Melanoma.

This article describes a proposed protocol for the histologic diagnosis of cutaneous melanoma developed for the National Cutaneous Melanoma Registry managed by the Spanish Academy of Dermatology and Venereology (AEDV). Following a review of the literature, 36 variables relating to primary tumors, sentinel lymph nodes, and lymph node dissection were evaluated using the modified Delphi method by a panel of 8 specialists (including 7 pathologists). Consensus was reached on the 30 variables that should be included in all pathology reports for cutaneous melanoma and submitted to the Melanoma Registry. This list can also serve as a model to guide routine reporting in pathology departments.

Clinical Practice Guideline on Melanoma From the Spanish Academy of Dermatology and Venereology (AEDV). / Guía de práctica clínica de melanoma de la Academia Española de Dermatología y Venereología.

Specialist approaches to the diagnosis and treatment of melanoma have undergone many changes. This guideline aims to provide Spanish dermatologists with evidence-based information for resolving the most common doubts that arise in clinical practice. Members of the Spanish Oncologic Dermatology and Surgery Group (GEDOC) with experience treating melanoma were invited to participate in drafting the guideline. The group developed a new guideline on the basis of existing ones, using the ADAPTE collaboration process, first summarizing the care process and posing relevant clinical questions, then selecting guidelines with the best scores according to the AGREE II (Appraisal of Guidelines for Research and Evaluation) tool. Finally, the group searched the selected guidelines for answers to the clinical questions, drafted recommendations, and sent them for external review. The guideline is structured around 21 clinical questions chosen for their relevance to issues that make clinical decisions about the management of melanoma difficult. Evidence from existing guidelines was used to answer the questions. A limitation of this guide derives from the scarce evidence available for answering some questions. Moreover, some areas are changing rapidly, so recommendations must be updated often. The present guideline offers answers to clinical questions about the routine management of melanoma in clinical practice and provides dermatologists with a reference to guide decisions, taking into consideration the resources available and patient preferences.

SARS-CoV-2 endothelial infection causes COVID-19 chilblains: histopathological, immunohistochemical and ultrastructural study of seven paediatric cases.

BACKGROUND: Chilblains ('COVID toes') are being seen with increasing frequency in children and young adults during the COVID-19 pandemic. Detailed histopathological descriptions of COVID-19 chilblains have not been reported, and causality of SARS-CoV-2 has not yet been established. OBJECTIVES: To describe the histopathological features of COVID-19 chilblains and to explore the presence of SARS-CoV-2 in the tissue. METHODS: We examined skin biopsies from seven paediatric patients presenting with chilblains during the COVID-19 pandemic. Immunohistochemistry for SARS-CoV-2 was performed in all cases and electron microscopy in one. RESULTS: Histopathology showed variable degrees of lymphocytic vasculitis ranging from endothelial swelling and endotheliitis to fibrinoid necrosis and thrombosis. Purpura, superficial and deep perivascular lymphocytic inflammation with perieccrine accentuation, oedema, and mild vacuolar interface damage were also seen. SARS-CoV-2 immunohistochemistry was positive in endothelial cells and epithelial cells of eccrine glands. Coronavirus particles were found in the cytoplasm of endothelial cells on electron microscopy. CONCLUSIONS: Although the clinical and histopathological features were similar to other forms of chilblains, the presence of viral particles in the endothelium and the histological evidence of vascular damage support a causal relation of the lesions with SARS-CoV-2. Endothelial damage induced by the virus could be the key mechanism in the pathogenesis of COVID-19 chilblains and perhaps also in a group of patients severely affected by COVID-19 presenting with features of microangiopathic damage. What is already known about this topic? Despite the high number of cases of chilblains seen during the COVID-19 pandemic, a definite causative role for SARS-CoV-2 has not yet been proven. Different pathogenetic hypotheses have been proposed, including coagulation anomalies, interferon release and external factors. What does this study add? The demonstration of SARS-CoV-2 in endothelial cells of skin biopsies by immunohistochemistry and electron microscopy confirms that these lesions are part of the spectrum of COVID-19. Virus-induced vascular damage and secondary ischaemia could explain the pathophysiology of COVID-19 chilblains. Our findings support the hypothesis that widespread endothelial infection by SARS-CoV-2 could have a pathogenetic role in the severe forms of COVID-19. Linked Comment: Wetter. Br J Dermatol 2020; 183:611.

Correction to: Liquid biopsy in oncology: a consensus statement of the Spanish Society of Pathology and the Spanish Society of Medical Oncology.

The article Liquid biopsy in oncology.

Liquid biopsy in oncology: a consensus statement of the Spanish Society of Pathology and the Spanish Society of Medical Oncology.

The proportion of cancer patients with tumours that harbour a potentially targetable genomic alteration is growing considerably. The diagnosis of these genomic alterations can lead to tailored treatment at the onset of disease or on progression and to obtaining additional predictive information on immunotherapy efficacy. However, in up to 25% of cases, the initial tissue biopsy is inadequate for precision oncology and, in many cases, tumour genomic profiling at progression is not possible due to technical limitations of obtaining new tumour tissue specimens. Efficient diagnostic alternatives are therefore required for molecular stratification, which includes liquid biopsy. This technique enables the evaluation of the tumour genomic profile dynamically and captures intra-patient genomic heterogeneity as well. To date, there are several diagnostic techniques available for use in liquid biopsy, each one of them with different precision and performance levels. The objective of this consensus statement of the Spanish Society of Pathology and the Spanish Society of Medical Oncology is to evaluate the viability and effectiveness of the different methodological approaches in liquid biopsy in cancer patients and the potential application of this method to current clinical practice. The experts contributing to this consensus statement agree that, according to current evidence, liquid biopsy is an acceptable alternative to tumour tissue biopsy for the study of biomarkers in various clinical settings. It is therefore important to standardise pre-analytical and analytical procedures, to ensure reproducibility and generate structured and accessible clinical reports. It is essential to appoint multidisciplinary tumour molecular boards to oversee these processes and to enable the most suitable therapeutic decisions for each patient according to the genomic profile.

Prognostic implications of markers of the metabolic phenotype in human cutaneous melanoma.

BACKGROUND: Reprogramming of energy metabolism to enhanced aerobic glycolysis has been defined as a hallmark of cancer. OBJECTIVES: To investigate the role of the mitochondrial proteins, ß-subunit of the H+ -ATP synthase (ß-F1-ATPase), and heat-shock protein 60 (HSP60), and the glycolytic markers, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and pyruvate kinase M2 (PKM2), as well as the bioenergetic cellular (BEC) index, in melanoma progression. MATERIALS AND METHODS: The expression of energy metabolism proteins was assessed on a set of different melanoma cells representing the natural biological history of the disease: primary cultures of melanocytes, radial (WM35) and vertical (WM278) growth phases, and poorly (C81-61-PA) and highly (C8161-HA) aggressive melanoma cells. Cohorts of 63 melanocytic naevi, 55 primary melanomas and 35 metastases were used; and 113 primary melanoma and 33 metastases were used for validation. RESULTS: The BEC index was significantly reduced in melanoma cells and correlated with their aggressive characteristics. Overexpression of HSP60, GAPDH and PKM2 was detected in melanoma human samples compared with naevi, showing a gradient of increased expression from radial growth phase to metastatic melanoma. The BEC index was also significantly reduced in melanoma samples and correlated with worse overall and disease-free survival; the multivariate Cox analysis showed that the BEC index (hazard ratio 0·64; 95% confidence interval 0·4-1·2) is an independent predictor for overall survival. CONCLUSIONS: A profound alteration in the mitochondrial and glycolytic proteins and in the BEC index occurs in the progression of melanoma, which correlates with worse outcome, supporting that the alteration of the metabolic phenotype is crucial in melanoma transformation.

Dermatomyositis panniculitis: a clinicopathological and immunohistochemical study of 18 cases.

BACKGROUND: Panniculitis occurring in dermatomyositis is uncommon, with only a few cases described in the literature, most of them as case reports. OBJECTIVE: This report describes the clinicopathological and immunohistochemical findings in a series of 18 patients with panniculitis associated with dermatomyositis. METHODS: In each patient, we collected the clinical data of the cutaneous lesions as well as the characteristic clinical and laboratory findings. A series of histopathologic findings was recorded in the biopsy of each patient. A panel of antibodies was used in some cases to investigate the immunophenotype of the infiltrate. Data of treatment and follow-up were also collected. RESULTS: Of the 18 patients, 13 were female and 5 were male, ranging in age from 13 to 74 years (median, 46.4 years). In addition to panniculitis, all patients presented pathognomonic cutaneous findings of DM and reported proximal muscle weakness prior to the diagnosis of panniculitis. Muscle biopsy was performed in 17 patients and MRI in one, all with the diagnosis of inflammatory myopathy. None of the patients presented any associated neoplasia. Panniculitis lesions were located in the upper or lower limbs. Histopathology showed a mostly lobular panniculitis with lymphocytes as the main component of the infiltrate. Most cases showed also numerous plasma cells and lymphocytes surrounding necrotic adipocytes (rimming) were frequently seen. Lymphocytic vasculitis and abundant mucin interstitially deposited between collagen bundles of the dermis were also frequent findings. Late-stage lesions showed hyaline necrosis of the fat lobule and calcification. Immunohistochemistry demonstrated that most lymphocytes of the infiltrate were T-helper lymphocytes, with some B lymphocytes in the lymphoid aggregates and small clusters of CD-123-positive plasmacytoid dendritic cells in the involved fat lobule. CONCLUSION: Panniculitis in dermatomyositis is rare. Histopathologic findings of panniculitis dermatomyositis are identical to those of lupus panniculitis. Therefore, the final diagnosis requires clinic-pathologic correlation.

Phacomatosis pigmentokeratotica: a case of HRAS mosaicism causing rhabdomyosarcoma.

A 17-year-old male presented with a large sebaceous naevus (SN) comprising part of his right face and scalp and a speckled lentiginous naevus (SLN) on his left trunk, hip, neck and scalp with a checkerboard pattern. His right oral hemimucosa showed extensive papillomatous lesions, which were contiguous with the upper-lip SN lesions. He also showed extracutaneous manifestations including cardiac, musculoskeletal and ocular alterations. Internally, he had developed two primary rhabdomyosarcomas. DNA samples of the SN, SLN, oral papillomatous hyperplasia and both rhabdomyosarcomas were analysed by Sanger sequencing. An HRAS c.37G>C mutation was detected in all of them. Skin and blood DNA were wild-type. Phacomatosis pigmentokeratotica (PPK) is characterized by the association of an SN with a papular naevus spilus and extracutaneous manifestations. Until recently, the aetiopathogenetic hypothesis of didymosis was accepted. However, in 2013 Groesser et al. proved the existence of an activating HRAS mutation as the cause of this syndrome. A higher incidence of cancer has been observed in germline RASopathies. Furthermore, up to 30% of human cancers show dysregulation of the Ras-Raf-MEK-ERK pathways. In our patient, an HRAS mosaic mutation explains not only the cutaneous but also the extracutaneous manifestations. To our knowledge this is the first described case of PPK in which the existence of an HRAS mosaic mutation is the confirmed cause of rhabdomyosarcoma. Furthermore, the HRAS c.37G>C mutation has never been related to any type of rhabdomyosarcoma. Mosaicisms could be underdiagnosed causes of childhood tumours. As dermatologists we stand in a privileged position of being able to detect these alterations.

Linear immunoglobulin A dermatosis mimicking toxic epidermal necrolysis: a case report of etanercept treatment.

A 65-year-old pluripathological woman attended our hospital with a cutaneous eruption of sudden appearance after vancomycin treatment. She presented targetoid lesions affecting approximately 25-30% of her body surface, large erosions with mucosal lesions and positive Nikolsky sign. Under the initial clinical suspicion of toxic epidermal necrolysis (TEN), and considering the recent literature of successful use of etanercept in these cases, she was treated with a single dose of this antitumour necrosis factor (anti-TNF) agent. Subsequently, the exanthema progression stopped and resolution of the lesions happened in a few days. Later on, histopathology revealed a subepidermal blister with dense neutrophilic infiltrate and linear deposits of immunoglobulin A (IgA) on the dermoepidermal junction, allowing us to establish the diagnosis of drug-induced linear IgA dermatosis mimicking TEN. Linear IgA dermatosis can have severe clinical manifestations, even mimicking TEN, and can have high mortality, especially in drug-induced cases. We have not found any other report of linear IgA dermatosis treated with etanercept in the English literature. Anti-TNF medications could represent useful therapeutic alternatives in this dermatosis.

Oncogenic KIT mutations in different exons lead to specific changes in melanocyte phospho-proteome.

UNLABELLED: Mutations in the proto-oncogene c-KIT (KIT) are found in several cancers, and the site of these mutations differs markedly between cancer types. We used site directed mutagenesis to induce KIT(559), KIT(642) and KIT(816) mutations in primary human melanocytes (PHM) and we investigated the impact of each mutation on KIT function. We studied canonical KIT-signaling pathways by immunoblotting, and we used stable isotope labeling by amino acids in cell culture (SILAC) and kinase prediction models to identify kinases differently activated in respective mutants. We validated our results with the analysis of phosphorylation levels of selected substrates for each kinase. We concluded that CK1 ε and δ are more active in cell clones harboring KIT(559) and KIT(642) mutations, whereas PAK4 is more active in clones with KIT(816) mutation. Our findings might help to develop further therapeutic options for tumors with specific KIT mutations in different domains. BIOLOGICAL SIGNIFICANCE: Different types of cancers harbor mutations in the oncogene KIT. The use of small molecules inhibitors directly targeting KIT had a limited success in the treatment of patients with KIT mutant cancers. Our study describes specific phospho-proteome changes due to different KIT mutations, and provides targets of further therapeutic options.