Relación entre fibroxantoma atípico y sarcoma pleomórfico dérmico: histopatología de ambos y revisión de la literatura

The relation between atypical fibroxanthoma and pleomorphic dermal sarcoma has led to confusion and debate in the literature. Both tumors present on sun-exposed skin, typically on the head and neck, in patients of advanced age. Both are comprised of a variable mix of histiocytoid, spindle, epithelioid, and/or giant multinucleated cells with pleomorphic nuclei. No immunohistochemical diagnostic techniques have emerged to distinguish these tumors. Diagnosis is by exclusion. Histologically, atypical fibroxanthoma is seen as a well-circumscribed dermal nodule but there will be no evidence of extensive subcutaneous invasion, tumor necrosis, or lymphovascular or perineural invasion. Therefore, if any of the aforementioned features is present, the diagnosis would be pleomorphic dermal sarcoma. This narrative review of the literature aims to identify the distinguishing and overlapping histopathologic features of these 2 tumors as they have been described in case series.     

Infección cutánea por Mycobacterium marinum. Descripción de tres casos y revisión de la literatura

—Mycobacterium marinum is a causative pathogen of skin and soft tissue infections. Infection often occurs when the microorganism is inoculated by exposure to contaminated water of aquariums and swimming-pools. Mycobacterium marinum is only infectious in erosive skin; therefore, the most common locations are the body areas exposed to traumatism.Three cases of cutaneous infection caused by Mycobacterium marinum are described. Cultures from skin biopsy specimens revealed this organism in all cases. Patients received antibiotic treatment with different response in all of them.We discuss the characteristics of cutaneous infection caused by this mycobacteria, as well as the need of an adequate diferential diagnosis to carry out an appropriate diagnosis and treatment, in order to avoid the appearance of complications.     

Urticaria solar y erupción lumínica polimorfa con el uso de cámaras de bronceado

—Tanning-beds are related to various side effects including the exacerbation of a previous photodermatosis. In this article we present two cases of solar urticaria and one case of polymorphic light eruption (PLE) in individuals without a background of photosensitivity and with continuous use of tanning cabins as a common denominator. We carried out phototesting and blood chemistry and hematology in the three patients to exclude other possible causes of phototoxicity. The literature on solar urticaria and PLE related to the use of tanning-beds and tanning cabins is reviewed.     

Determinación de la dosis eritemática mínima y reacciones anómalas a radiación ultravioleta A según fototipo

BackgroundPhototesting is a technique that assesses the skin's sensitivity to UV radiation by determining the smallest dose of radiation capable of inducing erythema (minimal erythema dose [MED]) and anomalous responses to UV-A radiation. No phototesting protocol guidelines have been published to date.MethodologyThis was a multicenter prospective cohort study in which 232 healthy volunteers were recruited at 9 hospitals. Phototests were carried out with solar simulators or fluorescent broadband UV-B lamps. Each individual received a total of 5 or 6 incremental doses of erythemal radiation and 4 doses of UV-A radiation. The results were read at 24 hours.ResultsAt hospitals where solar simulators were used, the mean (SD) MED values were 23 (8), 28 (4), 35 (4), and 51 (6) mJ/cm² for skin phototypes i to iv, respectively. At hospitals where broadband UV-B lamps were used, these values were 28 (5), 32 (3), and 34 (5) mJ/cm² for phototypes ii to iv, respectively. MED values lower than 7, 19, 27, and 38 mJ/cm² obtained with solar simulators were considered to indicate a pathologic response for phototypes I to IV, respectively. MED values lower than 18, 24, and 24 mJ/cm² obtained with broadband UV-B lamps were considered to indicate a pathologic response for phototypes ii to iv, respectively. No anomalous responses were observed at UV-A radiation doses of up to 20 J/cm².ConclusionsResults were homogeneous across centers, making it possible to standardize diagnostic phototesting for the various skin phototypes and establish threshold doses that define anomalous responses to UV radiation.     

Nevos melanocíticos con atipia relacionada con su localización: presentación de una serie de casos y caracterización de su perfil inmunohistoquímico

BackgroundNevi of special sites (NOSS) are benign melanocytic lesions that occur at particular sites. Although the histological features of NOSS have been described, their immunophenotypic features have not been fully characterized.AimsTo present the clinicopathological characteristics of a case series of NOSS and to characterize their immunohistochemical profile.Materials and methodsThirty-five NOSS were assessed using immunoperoxidase staining techniques for the melanocytic (S100, Melan-A, and HMB45) and proliferation (Ki-67) markersResultsAll of the cases of NOSS showed concerning architectural changes (prominent lentiginous melanocytic proliferation, irregularities, crowdedness, and dyhesiveness of the nests), and cytological atypia (large nevomelanocytes with vesicular nuclei, clear cytoplasm, and dusty melanin pigment) that can lead to a misdiagnosis of atypical nevi or even melanomas. All of the cases of NOSS showed diffuse expression of S100 and Melan-A proteins. Ki-67 labeling index of the nevomelanocytes was extremely low. HMB45 protein expression was limited to the junctional and superficial dermal nevomelanocytes.ConclusionsNOSS can show histological features that can easily mimic atypical nevi or melanomas and this diagnostic consideration should be kept in mind to avoid their misdiagnosis. The expression of HMB45 protein in NOSS indicates that their nevomelanocytic cells have an activated phenotype. The decreased HMB45 protein expression following a gradient from junctional to deeper dermal localization in NOSS is indicative of their immunohistochemical maturation.     

Síndrome de Osler-Weber-Rendu y su relación con la dermatología

Osler-Weber-Rendu syndrome, also known as hereditary hemorrhagic telangiectasia, is a rare autosomal dominant disorder with an estimated worldwide prevalence of 1 case per 10,000 population. Its clinical manifestations are the result of arteriovenous malformations characterized by telangiectases that can affect the skin, mucous membranes, and solid organs and cause life-threatening conditions, such as liver disease, systemic emboli, and heart failure. Timely diagnosis is thus essential in order to prevent disease-related complications and offer genetic counseling to families. We review the clinical features of Osler-Weber-Rendu syndrome with a focus on mucocutaneous manifestations and their treatment.     

Amiloidosis secundaria como complicación de artropatía psoriásica

Amyloidosis is a heterogeneous group of disorders characterized by extracellular deposition of fibrillar protein. Secondary amyloidosis occurs in patients with chronic infectious or inflammatory processes and tumours. AA can be isolated from secondary amyloidosis. It has been only rarely associated with psoriasis; this association may be fatal, because of renal involvement. We report a case of secondary amyloidosis associated with psoriatic arthopathy in a young woman. She received therapy with the antitumour necrosis factor alpha monoclonal antibody infliximab with improvement of her skin lesions.     

Uso de probióticos para disminuir la gravedad de la dermatitis atópica en población pediátrica: revisión sistemática y metaanálisis

Background and objectiveProbiotics, defined as live microbial dietary supplements that provide health benefits for the host, have been suggested as a treatment for atopic dermatitis based on a variety of proposed mechanisms of action. We analyzed evidence for the efficacy of probiotics to attenuate the severity of atopic dermatitis in pediatric patients younger than the age of 18 years.Material and methodsSystematic review of trials of probiotics that included patients under the age of 18 years with a confirmed diagnosis of atopic dermatitis scored for severity using the Scoring Atopic Dermatitis SCORAD) tool. We performed a meta-analysis of the randomized placebo controlled trials. The following databases were searched: MEDLINE, Web of Science, Scopus, ClinicalTrials.gov, Epistemonikos, Trip Medical Database, and the Spanish Virtual Health Library.ResultsTwenty trials were retrieved and included in the systematic review. Sixteen supported the use of probiotics to attenuate SCORAD-evaluated severity. Meta-analysis found an overall mean difference in effect between probiotics and placebo of −0.38 (95% CI, −0.63 to −0.14) in favor of probiotics. However, trial heterogeneity was high (I² statistic, 76%) due to clinical and methodological variability.ConclusionsIn spite of clinical heterogeneity in trials attributable to different types of probiotic products and doses, and to the subjective variability of the SCORAD scale, we conclude that probiotics are beneficial for reducing the severity of atopic dermatitis as reflected by the SCORAD index.     

Afectación cutánea específica por enfermedad de Hodgkin

—In Hodgkin's disease, the most frequent skin lesions are non-specific and include pruritis, ichthyosis, urticaria, hyperpigmentation, erythema multiforme and erythema nodosum. Specific cutaneous involvement in Hodgkin's disease occurs in 0.5-7.5 % of diagnosed patients. This involvement often corresponds to cutaneous lesions secondary to known lymph node Hodgkin's disease, and most patients are usually in very advanced stages of the disease.We present the case of a 73-year-old woman diagnosed with lymphocyte-depletion Hodgkin's disease, stage IV, in treatment with palliative radiotherapy. The patient presented with several subcutaneous plaques in the lumbosacral region, erythematous, very infiltrated to palpation, only a few centimeters in diameter and not painful. A biopsy was performed, in which the presence of an infiltrate with anaplastic cells, lymphocytes, eosinophils, Reed-Sternberg cells and Hodgkin's cells could be seen. Immunohistochemistry studies showed positivity for CD30 and CD15 and negativity for CD45, which confirmed the specific skin involvement from the underlying disease.