The Ectodysplasin receptor EDAR acts as a tumor suppressor in melanoma by conditionally inducing cell death.

Ectodysplasin receptor EDAR is seen as a typical Tumor Necrosis Factor receptor (TNFR) family member known to interact with its ligand Eda-A1, and signaling mainly through the nuclear factor-kappaB (NF-κB) and c-jun N-terminal kinases pathways. Mutations in genes that encode proteins involved in EDAR transduction cascade cause anhidrotic ectodermal dysplasia. Here, we report an unexpected pro-apoptotic activity of EDAR when unbound to its ligand Eda-A1, which is independent of NF-κB pathway. Contrarily to other death receptors, EDAR does recruit caspase-8 to trigger apoptosis but solely upon ligand withdrawal, thereby behaving as the so-called dependence receptors. We propose that pro-apoptotic activity of unbound EDAR confers it a tumor suppressive activity. Along this line, we identified loss-of-pro-apoptotic function mutations in EDAR gene in human melanoma. Moreover, we show that the invalidation of EDAR in mice promotes melanoma progression in a B-Raf mutant background. Together, these data support the view that EDAR constrains melanoma progression by acting as a dependence receptor.

Association of subungual melanoma and subungual squamous cell carcinoma: A case series.

BACKGROUND: Subungual squamous cell carcinoma (SSCC) and subungual melanoma (SUM) are rare tumors. Several case reports of association of SSCC with SUM (SSCC-SUM) have been published. OBJECTIVE: We sought to document the clinical, dermoscopic, and histologic features in a case series of SSCC-SUMs and describe their relative frequency compared with those of SSCC and SUM. METHODS: All patients who underwent surgical exploration of the nail apparatus with a dermatopathologic examination from 2012 to 2015 were reviewed retrospectively to identify all cases of SSCC, SUM, and SSCC-SUM. For patients with SSCC-SUM, clinical characteristics were obtained from electronic medical records. All histologic specimens were reviewed by 3 dermatopathologists. RESULTS: The medical records of 456 patients were reviewed. SSCC was diagnosed in 78 (17%), SUM was diagnosed in 63 (14%), and SSCC-SUM was diagnosed in 9. Patients with SSCC-SUM accounted for 11% of those with a diagnosis of SSCC (9 of 78) and 14% of those with a diagnosis of SUM (9 of 63). LIMITATIONS: This was a single-institution retrospective study. CONCLUSION: The association of SSCC and SUM is relatively frequent in patients with SUM and warrants further consideration to understand the underlying mechanisms involved.

ZEB1-mediated melanoma cell plasticity enhances resistance to MAPK inhibitors.

Targeted therapies with MAPK inhibitors (MAPKi) are faced with severe problems of resistance in BRAF-mutant melanoma. In parallel to the acquisition of genetic mutations, melanoma cells may also adapt to the drugs through phenotype switching. The ZEB1 transcription factor, a known inducer of EMT and invasiveness, is now considered as a genuine oncogenic factor required for tumor initiation, cancer cell plasticity, and drug resistance in carcinomas. Here, we show that high levels of ZEB1 expression are associated with inherent resistance to MAPKi in BRAFV600-mutated cell lines and tumors. ZEB1 levels are also elevated in melanoma cells with acquired resistance and in biopsies from patients relapsing while under treatment. ZEB1 overexpression is sufficient to drive the emergence of resistance to MAPKi by promoting a reversible transition toward a MITFlow/p75high stem-like and tumorigenic phenotype. ZEB1 inhibition promotes cell differentiation, prevents tumorigenic growth in vivo, sensitizes naive melanoma cells to MAPKi, and induces cell death in resistant cells. Overall, our results demonstrate that ZEB1 is a major driver of melanoma cell plasticity, driving drug adaptation and phenotypic resistance to MAPKi.

Melanoma patients under vemurafenib: prospective follow-up of melanocytic lesions by digital dermoscopy.

Second primary melanomas (SPMs) induced by vemurafenib have been recently described. The aim of this study was to define the dermoscopical signs of melanoma in this context. Patients underwent a total body examination before receiving vemurafenib. Each single melanocytic lesion was registered before therapy by digital dermoscopy (DD), and then repeated monthly until therapy disruption. Forty-two patients were included, the mean duration of follow-up was 6.7 months, and a mean number of 51 lesions per patients were captured and followed. A total number of 2,155 lesions were recorded, of which 56.1% presented at least one change during the study. More common changes concerned the color of the lesions (up to 15%) and appearance or disappearance of globules (14.6%). Thirty-six of the melanocytic lesions were surgically excised, 21 were classified as a nevus, 1 was a lentigo, and 14 as a second new primary melanoma (occurring in 21% of our patients). DD allowed us to excise only 36/2,155 (1.6%) of the lesions and permitted us to detect 14 SPM in the 42 patients with a highly efficient malignant/benign ratio of 63.6%. Although vemurafenib is now tested in an adjuvant setting DD should be systematically used in order to accurately detect SPM and reduce the number of unnecessary excisions.

Reflectance confocal microscopy characteristics of eight cases of pustular eruptions and histopathological correlations.

BACKGROUND: Reflectance confocal microscopy (RCM)'s interest has been well established for the non-invasive diagnosis of skin cancers, especially melanocytic, and in the differential diagnosis between benign and malignant cutaneous lesions. However, its diagnostic interest in inflammatory skin diseases still needs to be demonstrated. Our purpose was to evaluate the correlation between RCM and conventional histopathology in a series of pustular eruptions of different pathogeny. METHODS: Reflectance confocal microscopy analysis was performed in eight consecutive unselected patients in whom the diagnoses of pustular psoriasis, bacterial sur-infection, herpes-type virus skin sur-infection, Sneddon-Wilkinson subcorneal putulosis and Hailey-Hailey disease have been made and images were compared to conventional histopathology. RESULTS: Neutrophils within the epidermis exhibited never reported earlier specific features, with either a shiny granular sludge or polylobated particules with a bright granular content. Moreover, some specific etiologies could be identified, such as acantholysis and herpes-type virus-infected keratinocytes. CONCLUSION: Our studies show a good correlation between RCM and conventional histopathology in pustular eruptions. Reflectance confocal microscopy may play an important role in the differential diagnosis of pustular eruptions; as most of the pathologic clues are epidermal, narrow thickness of the field of imaging, its main technical limitation, is indeed of lesser importance.

Histological features and treatment approach of trichoblastic carcinomas: from a case report to a review of the literature.

BACKGROUND: Trichoblastic carcinoma (or malignant trichoblastoma) is a rare malignant cancer of adnexal structures with morphological features that in some cases are reminiscent of a trichoblastoma. Trichoblastic carcinoma is underdiagnosed as it is a rather recent entity which is still not recognized as such by all pathologists. The differential diagnosis with basal cell carcinoma is often difficult to make and the optimal treatment has not yet been established. CASE REPORT: We report the case of a 43-year-old patient who underwent surgical excision and adjuvant radiotherapy for a growing mass of 40 × 48 mm located in the lumbar right paraspinal skin. The pathological findings demonstrated a trichoblastic carcinoma. The clinicopathological profile, the histogenesis, and the difficulties related to the histopathological diagnosis and treatment of this rare entity are discussed in this article. CONCLUSION: Although the published reports on this disease are few, surgery should be considered the standard therapeutic approach for trichoblastic carcinomas. Selected cases presenting clinical features of local aggressiveness can safely be treated with adjuvant irradiation to improve local control. However, acute and particularly late toxicities need to be taken into account in the decision.

Tumor blástico a células dendríticas plasmocitoides / Blastic neoplasm of plasmocytoid dendritic cells

El tumor blástico a células dendríticas plasmacitoides (TBCDP) es una malignidad hematopoyética rara, altamente agresiva, derivada de las células dendríticas plasmocitoides; se caracteriza por su alta incidencia de compromiso cutáneo, que a menudo termina en una fase leucémica de mal pronóstico. La primera manifestación de la enfermedad pueden ser placas y tumores solitarios o múltiples, de manera que la biopsia cutánea es crucial para el diagnóstico. En la histopatología se observa un infiltrado difuso, monomorfo, no epidermotrópico de células de tamaño mediano con núcleos redondos, cromatina finamente dispersa, CD4 + CD56 + CD 123 +. Presentamos el caso de una paciente de sexo femenino de 48 años con un tumor plasmocitoide de células dendríticas. Al examen dermatológico se observaron lesiones cutáneas en cara externa de la pierna izquierda y mama derecha, acompañados de adenopatías inguinales palpables. No se halló compromiso de médula ósea y el hemograma fue normal. La paciente fue tratada con metotrexato, L-asparaginasa y dexametasona con buena respuesta clínica. El trasplante alogénico fue propuesto después del tercer ciclo.

Blastic neoplasm of plasmacytoid dendritic cells (BNPDC) is a rare hematopoietic malignancy, highlyaggressive, derived from plasmacytoid dendritic cells, and is characterized by a high incidence of cutaneousinvolvement, common leukemic dissemination and poor prognosis. Solitary or multiple skin plaques andtumors are often the first clinical manifestations of the disease; thus, cutaneous biopsies are crucial tocorrectly classify the patients. Histopathologic features are characterized by diffuse, monomorphous, nonepidermotropic infiltrates of medium-sized cells with round nuclei, finely dispersed chromatin CD4+CD56+ CD123+. We describe a 48-year-old woman who presented BNPDC. Clinically, two isolated bruiselikelesions arising on her left leg and right breast were detected, with palpable inguinal lymph nodes.Peripheral blood smear was normal, and the bone marrow was not involved. The patient was treatedwith methotrexate, L- asparaginase and dexametasone before entering in an allogenic bone marrowtransplantation program.

Tumor blástico a células dendríticas plasmocitoides / Blastic neoplasm of plasmocytoid dendritic cells

El tumor blástico a células dendríticas plasmacitoides (TBCDP) es una malignidad hematopoyética rara, altamente agresiva, derivada de las células dendríticas plasmocitoides; se caracteriza por su alta incidencia de compromiso cutáneo, que a menudo termina en una fase leucémica de mal pronóstico. La primera manifestación de la enfermedad pueden ser placas y tumores solitarios o múltiples, de manera que la biopsia cutánea es crucial para el diagnóstico. En la histopatología se observa un infiltrado difuso, monomorfo, no epidermotrópico de células de tamaño mediano con núcleos redondos, cromatina finamente dispersa, CD4 + CD56 + CD 123 +. Presentamos el caso de una paciente de sexo femenino de 48 años con un tumor plasmocitoide de células dendríticas. Al examen dermatológico se observaron lesiones cutáneas en cara externa de la pierna izquierda y mama derecha, acompañados de adenopatías inguinales palpables. No se halló compromiso de médula ósea y el hemograma fue normal. La paciente fue tratada con metotrexato, L-asparaginasa y dexametasona con buena respuesta clínica. El trasplante alogénico fue propuesto después del tercer ciclo. (AU)

Blastic neoplasm of plasmacytoid dendritic cells (BNPDC) is a rare hematopoietic malignancy, highlyaggressive, derived from plasmacytoid dendritic cells, and is characterized by a high incidence of cutaneousinvolvement, common leukemic dissemination and poor prognosis. Solitary or multiple skin plaques andtumors are often the first clinical manifestations of the disease; thus, cutaneous biopsies are crucial tocorrectly classify the patients. Histopathologic features are characterized by diffuse, monomorphous, nonepidermotropic infiltrates of medium-sized cells with round nuclei, finely dispersed chromatin CD4+CD56+ CD123+. We describe a 48-year-old woman who presented BNPDC. Clinically, two isolated bruiselikelesions arising on her left leg and right breast were detected, with palpable inguinal lymph nodes.Peripheral blood smear was normal, and the bone marrow was not involved. The patient was treatedwith methotrexate, L- asparaginase and dexametasone before entering in an allogenic bone marrowtransplantation program.(AU)

[Eosinophilic angiocentric fibrosis and granuloma facial with extra facial presentation, the same pathology?]. / Fibrose angiocentrique à éosinophiles et granulome facial à forme extrafaciale, une même entité ?

Eosinophilic angiocentric fibrosis is a rare fibro inflammatory lesion of unknown etiology which occurs usually in the upper respiratory tract mucosa of middle-aged adults. The histologic features show an eosinophilic vasculitis and an angiocentric fibrosis with onion-skin pattern. Firstly described as a mucosal variant of the granuloma facial, which is a rare cutaneous vasculitis with eosinophils, it is considerated by some authors as separated entities. Four cases have been described in the orbit and three of them were in fact an extension of a sinusal lesion. We report the first case affecting a 69-years-old male patient who showed an isolated orbital involvement in association with granuloma facial, extra facial. This observation illustrates the relationship between these two pathologies and consolidates the first hypothesis of a single disease with cutaneous or mucosal involvement.