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BackgroundHigh-risk mucosal human papillomavirus (HR-HPV) seems to play a role in cutaneous squamous cell carcinoma (cSCC), particularly in nail tumours, where genitodigital transmission has been suggested. The role of HR-HPV in nonungual cSCC of the finger needs to be clarified.AimTo evaluate the prevalence, clinicopathological characteristics, surrogates and outcomes of HR-HPV in cSCC of the finger.MethodsThis was an observational bicentric study including patients with an excised in situ or invasive cSCC located on the finger. Differences in HR-HPV and non-HR-HPV tumours were evaluated.ResultsForty-five patients (45 tumours) were included. HR-HPV was detected in 33% of cases (22% HPV type 16). The mean age was lower in patients with HR-HPV than in those with non-HR-HPV (62·4 vs. 81·1 years, P = 0·001). HR-HPV tumours were smaller (10 mm vs. 15 mm, P = 0·07) and more frequently intraepidermal (60% vs. 20%, P = 0·004). The absence of elastosis (P = 0·030) and inflammation (P = 0·026) and the presence of basaloid morphology (P = 0·003) were surrogates of HR-HPV detection. Mean p16 positivity was 61% in HR-HPV and 36% in non-HR-HPV tumours (P = 0·061). Recurrence after surgery was more common in HR-HPV tumours (58% vs. 34%), although this was not statistically significant. HR-HPV was detected in 27% of the nonungual tumours.ConclusionHR-HPV-associated cSCC of the finger appears in younger patients, is smaller and is less infiltrative than non-HR-HPV tumours. The presence of a basaloid morphology and the absence of elastosis and inflammation could be used as markers for HR-HPV detection. The high prevalence of HR-HPV in nonungual cSCC suggests its aetiopathogenic role in these tumours.

Following a recent report of xanthomas arising in a patient treated with etoposide for mycosis fungoides (MF), we present a similar patient with xanthomas and MF, who had not received any treatment. Further studies are needed to elucidate the origin and pathophysiology of normocholesterolaemic xanthomas associated with MF.

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.

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.

[Background]: Acantholytic cutaneous squamous cell carcinomas (aCSCCs) have been classically considered as a high-risk variant of CSCC. However, more recent studies show that aCSCC does not confer more aggressiveness. This study aims to establish whether the prognosis of the aCSCC is worse than that of the non-acantholytic (naCSCC) or not. [Methods]: Retrospective case-control study with 50 aCSCCs and 50 naCSCCs. For each aCSCC, an naCSCC with similar high-risk features to the aCSCC but with no acantholysis was selected. Prognosis between both groups was compared. [Results]: The mean age was 86 years (SD 9.61). Sixty-one patients were men. Thirty-nine CSCCs were located in high-risk head and neck areas. Twenty CSCCs exhibited a poor degree of differentiation, and 36 showed an infiltrative growth pattern. The tumor diameter was 18.71 mm (interquartile range, IQR 35), and the tumor thickness was 6.72 mm (IQR 15.50). Twelve CSCCs exhibited perineural infiltration, and eight CSCCs exhibited invasion beyond the subcutaneous fat. Positive margins after excision of the tumor in 22 aCSCCs vs eight naCSCCs (P, Instituto de Salud Carlos III, Grant/Award Number: PI18/000587

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.

Tattoos are characterized by the introduction of exogenous pigments into the dermis. Tattoos usually serve cosmetic purposes, although they may have other causes, such as traumatic pigment implants in accidents or medical-related tattoos in the context of radiotherapy. Dermatologic adverse reactions are relatively uncommon, and they include infections, immune-mediated reactions, cutaneous lesions secondary to the Koebner phenomenon, exacerbation of preexisting dermatosis, benign and malignant neoplasms, and a miscellaneous group of dermatologic conditions that may appear in a preexisting tattoo. The aim of this study is to review the types of histopathologic reactions that may appear in a preexisting permanent tattoo.

Resumen: La patología vascular oclusiva es causante de diversas y variadas manifestaciones clínicas, algunas de las cuales son de catastróficas consecuencias para el paciente. Sin embargo, las causas de tal oclusión son muy variadas, extendiéndose desde trombos por acción descontrolada de los mecanismos de coagulación, hasta anomalías de los endotelios de los vasos u oclusión por materiales extrínsecos. En una serie de dos artículos hacemos una revisión de las principales causas de oclusión vascular, resumiendo sus manifestaciones clínicas principales y los hallazgos histopatológicos fundamentales. Esta primera parte corresponde a las oclusiones vasculares que cursan con trombos. Abstract: Vascular occlusion has multiple, diverse clinical manifestations, some of which can have grave consequences for patients. The causes of vascular occlusion are also highly variable, ranging from thrombi triggered by the uncontrolled activation of coagulation mechanisms, on the one hand, to endothelial dysfunction or occlusion by material extrinsic to the coagulation system on the other. In a 2-part review, we look at the main causes of vascular occlusion and the key clinical and histopathologic findings. In this first part, we focus on vascular occlusion involving thrombi.

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.

La patología vascular oclusiva es causante de diversas y variadas manifestaciones clínicas, algunas de las cuales son de catastróficas consecuencias para el paciente. Sin embargo, las causas de tal oclusión son muy variadas, extendiéndose desde trombos por acción descontrolada de los mecanismos de coagulación, hasta anomalías de los endotelios de los vasos u oclusión por materiales extrínsecos. En una serie de dos artículos hacemos una revisión de las principales causas de oclusión vascular, resumiendo sus manifestaciones clínicas principales y los hallazgos histopatológicos fundamentales. Esta primera parte corresponde a las oclusiones vasculares que cursan con trombos.

Resumen: El presente texto es una propuesta de protocolo de diagnóstico histológico para el melanoma cutáneo realizada a instancias del Registro Nacional de Melanoma de la Academia Española de Dermatología y Venereología. Tras una búsqueda bibliográfica, un grupo de ocho panelistas (siete patólogos) decidieron entre 36 variables del tumor primario, el ganglio centinela y la linfadenectomía incluir un total de 30 variables mediante el método de Delphi modificado. Se han consensuado las variables que deberían contener un informe histológico de melanoma cutáneo para que puedan ser utilizadas en el Registro de Melanoma o servir de modelo para los distintos Servicios de Anatomía Patológica a la hora de elaborar sus propios informes de forma rutinaria. Abstract: 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.

Atypical fibroxanthoma is a rare mesenchymal skin tumor of intermediate malignancy that typically occurs on sun-damaged skin of elderly patients. Histologically, it is composed of pleomorphic cells with hyperchromatic nuclei and abundant cytoplasm, commonly arranged in a spindle cell pattern. Different histologic variants have been described during the past years. We present a case of atypical fibroxanthoma containing a dense inflammatory infiltrate, which in conjunction with the existence of immunoblast-like and Reed-Sternberg-like neoplastic cells could be misinterpreted as a lymphoid neoplasm. Immunohistochemical studies revealed strong positivity of tumor cells for CD10 and negativity for cytokeratins, p63, p40, S100, SOX10, ERG, actin, desmin, B and T-cell markers, BCL6, CD15, and CD30. The inflammatory infiltrate contained a mixed reactive T- and B-cell population with negative T-cell receptor and immunoglobulin heavy rearrangements. We discuss the differential diagnosis of this entity in which clinical, immunohistochemical, and molecular features are essential to avoid the diagnosis of a lymphoproliferative disease.

The novel coronavirus disease (COVID-19) is a rapidly spreading pandemic, secondary to severe acute respiratory syndrome coronavirus 2. The severity and the little knowledge that we have of the disease have made us focus mostly on the respiratory symptoms. As we bend the curve, other findings reported in association with COVID-19 become of importance for specialists to recognize. We describe the spectrum of clinicopathologic lesions in the skin that can be the only symptom or the first manifestation of COVID-19 and demonstrate the origin of the virus. We collected 25 patients with skin lesions in this context. We recognized 5 types of cutaneous manifestations including acute acroischemic or chilblain-like lesions (11), purpura palpable (2), exanthemas (9), urticarial eruptions (1), and other lesions (2) that might appear with more unspecific pictures. Chilblain-like lesions were the most common form of presentation, which tend to appear as self-healing, erythematous-necrotic plaques mostly on the feet, in young patients with no systemic symptoms associated. Importantly, we visualized viral particles with electron microscopy in 5 of 13 cases analyzed. In this study, we seek to draw a picture of the spectrum of clinicopathologic lesions that may appear in the skin in the context of COVID-19. Although apparently skin lesions are not correlated with disease severity, it may help in some cases to recognize and control the spread of the infection sooner.

Background The introduction of immune checkpoint inhibitors (ICI) has improved the survival outcomes of patients with advanced melanoma. To date, only a few studies have evaluated the immunohistochemical (IHC) expression of PD-1 and CTLA-4 in tumor-infiltrating lymphocytes (TILs) as predictive markers of response to ICI, most of them in the context of clinical trials. Moreover, the predictive value of PD-L1 in melanoma cells in the response to immunotherapy is unclear. The aim of our study was to assess the IHC expression of PD-L1, PD-1, and CTLA-4 in samples of patients with advanced melanoma and to establish their prognostic value as predictors of ICI response in a university hospital. Methods The expression of PD-L1, PD-1, and CTLA-4 was evaluated in pretreatment tumor samples in a series of 35 patients, 21 patients treated with nivolumab and 14 patients with ipilimumab in monotherapy. Results In the nivolumab group, 4 tumors (19%) were positive for PD-L1 and all of them showed a partial response to the treatment. However, 4 patients whose tumors did not express PD-L1 also responded to nivolumab. PD-1 expression was not associated with better progression-free survival (PFS). In the ipilimumab group, 5 patients (35.7%) showed expression of CTLA-4. Positive cases showed a better PFS; however, one negative case responded to ipilimumab. Conclusions Nivolumab produces a better response compared with ipilimumab in patients with melanoma. The IHC expression of PD-L1 and CTLA-4 are associated with a higher response rate to nivolumab and ipilimumab, respectively, and better PFS, but the existence of responder patients with negative expression suggests that they are not adequate biomarkers to select candidate patients for ICI in the clinical practice.

Vascular occlusion has multiple, diverse clinical manifestations, some of which can have grave consequences for patients. The causes of vascular occlusion are also highly variable, ranging from thrombi triggered by the uncontrolled activation of coagulation mechanisms, on the one hand, to endothelial dysfunction or occlusion by material extrinsic to the coagulation system on the other. In a 2-part review, we look at the main causes of vascular occlusion and the key clinical and histopathologic findings. In this first part, we focus on vascular occlusion involving thrombi. (C) 2020 AEDV. Published by Elsevier Espana, S.L.U.

To the Editor: Perineural invasion (PNI) is rare and usually incidental in cutaneous squamous cell carcinoma (SCC), with an incidence of 2.5% to 14%.1 Incidental PNI is associated with poor prognosis in cutaneous SCC,2 and some evidence suggests its outcome differs, depending on the PNI pattern. We evaluated patterns of incidental PNI, using a multicenter retrospective cohort of 140 cutaneous SCCs with incidental PNI to determine the influence of nerve involvement on cutaneous SCC prognosis., Dr Canueto is partially supported ~ by grants PI18/000587 (Instituto de Salud Carlos III, cofinanced by Fondo Europeo de Desarrollo Regional) and GRS 1835/A/18 (Gerencia Regional de Salud de Castilla y Leon).

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.

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. (C) 2021 AEDV. Published by Elsevier Espana, S.L.U.

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 part I of this review. In this second part, we look at additional causes of vascular occlusion. (C) 2020 AEDV. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY license.

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. (C) 2021 AEDV. Published by Elsevier Espana, S.L.U.

Crystalglobulinemia is an extremely rare pathology that is associated in most cases with plasma cell dyscrasia, mainly multiple myeloma. In most cases, it may be the manifestation of incipient gammopathy or it manifests shortly after diagnosis. We report a patient with ischemic lesions of thrombotic origin in lower limbs. Subsequently, renal involvement occurs, in view of this involvement, it is suspected that the patient may have an associated vasculitis. After performing the biopsy and with the subsequent diagnosis of monoclonal gammopathy of uncertain significance, the diagnosis is made. We review the most recent bibliography of patients who have been diagnosed with crystalglobulinemia associated with plasma dyscrasia focusing in those with thrombotic vasculopathy or acute renal failure. In our case, in addition to being associated with monoclonal gammopathy of undetermined significance that is less frequent, the debut of the symptoms is years before the detection of the monoclonal peak. This could speak of patients with a low peak of monoclonal component (not detected by immunoelectrophoresis) who could have kidney and vascular damage.

Graft-versus-host disease (GVHD) is one of the most common and serious complications of hematopoietic stem-cell transplantation that mainly affects the skin, gastrointestinal tract, and liver. Hepatic GVHD is associated with high morbidity and mortality, and its diagnosis can be especially challenging because of nonspecific clinical signs and symptoms. It must be suspected in patients with elevated liver enzymes and cholestasis, especially in those with a history of preceding skin rash and diarrhea. We describe 3 patients with cutaneous and hepatic GVHD that presented with severe hypercholesterolemia and hypertriglyceridemia, and no xanthomatous macular lesions, in which cutaneous biopsies revealed the presence of xanthomatous dermal histiocytes. We propose that the presence of these xanthomatous cells in skin biopsies from patients with cutaneous GVHD could be a dermatopathological clue for the diagnosis of hepatic GVHD.

BackgroundPanniculitis occurring in dermatomyositis is uncommon, with only a few cases described in the literature, most of them as case reports. ObjectiveThis report describes the clinicopathological and immunohistochemical findings in a series of 18 patients with panniculitis associated with dermatomyositis. MethodsIn 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. ResultsOf 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. ConclusionPanniculitis in dermatomyositis is rare. Histopathologic findings of panniculitis dermatomyositis are identical to those of lupus panniculitis. Therefore, the final diagnosis requires clinic-pathologic correlation. Linked article: This article is commented on by A. Kuhn, pp. 1231-1232 in this issue. To view this article visit

The identification of B-Raf proto-oncongene ( BRAF ) mutation and the emergence of targeted therapy marked a turning point in the treatment of melanoma. The study of mutation status concordance between primary tumors and metastases in this cancer has major treatment implications as it facilitates the selection of candidates for targeted therapy. This review analyzes the evidence on the level of mutation status concordance between primary tumors and different types of metastases in cutaneous melanoma and provides an overview of the advantages and disadvantages of the various methods used to detect BRAF mutations.

Allogeneic hematopoietic stem-cell transplantation and solid-organ transplantation are associated with an increased risk of secondary neoplasms. Indeterminate cell histiocytosis (ICH) is a rare disease composed of so-called indeterminate cells, an alleged cutaneous dendritic cell subset displaying histological and some ultrastructural and immunophenotypic features of Langerhans cells but lacking Birbeck granules. We report a case of cutaneous ICH occurring after allogeneic hematopoietic stem-cell transplantation for a myelodysplastic syndrome in a 56-year-old man. Microsatellite analysis demonstrated that the neoplastic cells were derived from the donor's hematopoietic system. This case broadens the spectrum of complications after stem-cell transplantation and demonstrates that cutaneous ICH in the setting of myelodysplastic syndromes may have a nonrelated origin to dysplastic myeloid cells.

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.

The occurrence of Pacinian corpuscles associated to lymph nodes is an anatomical rarity and very scarce information exists in this regard. Here we examined immunohistochemically four Pacinian corpuscles found in the close vicinity of the hiliar blood vessels of lymph nodes (2 cervical, 1 axillary, and 1 inguinal) during routine surgical pathology. Pacinian corpuscles were normally arranged and displayed a pattern of protein distribution as follows: the axon was positive for neurofilament proteins and neuron specific enolase, the inner core cells showed intense S100 protein and vimentin immunostaining while they were negative for glial fibrillary acidic protein, type IV collagen and glucose transporter 1; vimentin, type IV collagen, and glucose transporter 1 were also observed also in the outer-core and the capsule. These results are in agreement with those reported for cutaneous Pacinian corpuscles, demonstrating that the immunohistochemical profile of these corpuscles is independent of its anatomical localization. The possible functional significance of Pacinian corpuscles in lymph nodes is discussed. Anat Rec, 300:2233-2238, 2017. © 2017 Wiley Periodicals, Inc.

Degos disease (DD) or papulosis atrophicans maligna, is an extremely infrequent thrombotic microangiopathy of unknown etiology(1). Clinically, it is characterized by small erythematous papules with an atrophic center that may simulate a simple scar and distinct histopathological feature that is not always present. Due to the rarity of this entity, diagnosis may go unnoticed with the first onset of cutaneous lesions. Therefore, high clinical suspicion and adequate clinicopathological correlation are required to establish an early diagnosis and consequently treatment. This article is protected by copyright. All rights reserved.

Therapies targeting the BRAF oncogene have improved the overall and disease-free survival of patients with advanced melanomas. An unresolved issue in clinical practice is the existence (or not) of BRAF-mutated and BRAF-nonmutated tumors in individual patients (intrapatient BRAF mutation heterogeneity), which may serve as a mechanism of resistance to BRAF inhibitors or lead to diagnostic problems. Different research groups have reported differing results after analyzing the BRAF mutation statuses of multiple melanoma tumors. Herein, we present a brief revision of the literature on this controversial topic and propose a theory to justify the divergence of the results found in the literature.

[Background]: Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans after basal cell carcinoma, and its incidence is dramatically rising. CSCC is rarely problematic, but given its high frequency, the absolute number of complicated cases is also high. It is necessary to identify molecular markers in order to recognize those CSCCs with poor prognosis. There is controversy concerning the role of epidermal growth factor receptor (EGFR) as a marker of prognosis in CSCC. In addition, EGFR-targeted therapies have emerged in recent years and a better understanding of the role of EGFR in CSCC may be of help for some patients in predicting prognosis and guiding curative management. [Objectives]: To evaluate the role of EGFR as a prognostic factor in CSCC. [Methods]: We evaluated clinical and histopathological features, including events of poor clinical evolution, in a series of 94 cases of CSCC. We also analysed EGFR expression by immunohistochemistry, fluorescent in situ hybridization and quantitative polymerase chain reaction. [Results]: We detected EGFR in 85 cases (90%), with overexpression in 33 cases (35%), and aberrant EGFR expression in the cytoplasm in 50 cases (53%). EGFR overexpression in the primary tumours was associated with lymph node progression, tumour–nodes–metastasis stage progression and proliferation (Ki-67 staining) in CSCC. EGFR overexpression and poor grade of differentiation were the strongest independent variables defining lymph node metastasis and progression in CSCC in a logistic regression model. [Conclusions]: We demonstrate that EGFR overexpression has prognostic implications associated with lymph node metastasis and progression in CSCC., J.P.‐L. was partially supported by FEDER and MICINN (PLE2009‐119, SAF2014‐56989‐R), Instituto de Salud Carlos III (PI07/0057, PI10/00328, PIE14/00066), Junta de Castilla y León (SAN673/SA26/08, SAN126/SA66/09, SA078A09, CSI034U13, BIO/SA31/15), IBSAL (IBY15/00003), the ‘Eugenio Rodríguez Pascual’, the ‘Fundación Inbiomed’ (Instituto Oncológico Obra Social de la Caja Guipozcoa‐San Sebastian, Kutxa) and the ‘Fundación Sandra Ibarra de Solidaridad frente al Cáncer’. C.R.‐C. is funded by Q3718001E (2009‐2010) and GRS 612/A/11 (2011‐2012) and ‘the Fundación Eugenio Rodríguez Pascual’. A.C.‐M. was supported by FIS (PI07/0057) and MICINN (PLE2009‐119).

Indeterminate dendritic cell tumor (IDCT) is a rare disease composed of so-called indeterminate cells, a dendritic cell subset displaying histological and some ultrastructural and immunophenotypic features of Langerhans cells, but lacking Birbeck granules. We report a case of cutaneous IDCT occurring in a patient with chronic myelomonocytic leukemia (CMML) successfully treated with UV-A phototherapy. Next-generation sequencing studies of the CMML demonstrated mutations in TET2, ASXL1, and ZRS2 genes, also detected in the IDCT, demonstrating a clonal relationship between both tumors and confirming IDCT as a specific subtype in the spectrum of CMML-related cutaneous lesions.

Background Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and can be both locally invasive and metastatic at distant sites. While research efforts have been made to predict poor outcome of CSCC, there is a lack of knowledge regarding molecular markers. PODOPLANIN has been associated with poor outcome in several types of cancer including CSCC, but this is controversial and only a few studies have evaluated the prognostic implications of Podoplanin in the development of this tumor. Methods We evaluated Podoplanin expression in a series of 94 CSCCs, and searched for associations between Podoplanin expression and histopathological characteristics and with events of poor clinical evolution of the disease. Results Podoplanin expression was observed in 48.9% of the cases and the expression was considered moderate to intense in 19 of the cases. Moderate/intense Podoplanin was associated with infiltrative growth pattern, desmoplasia, and lymphovascular invasion, and with a higher risk of nodal progression and with short disease-free survival, specifically with a short latency to nodal progression. Conclusions This paper provides evidence supporting the implication of Podoplanin expression as a marker of bad prognosis of CSCC.

Fibroblastic connective tissue nevus (FCTN) is a rare, benign, dermal mesenchymal hamartoma that affects children. We report a 15-year-old boy with a congenital FCTN and describe the clinical, dermatoscopic, and histopathologic features.