Breast myiasis in an elderly male patient: a case report.

Fly larvae cause myiasis. The most common of these are Cordylobia anthropophaga and Dermatobia hominis. Clinically, myiasis manifests as an erythematous papule that may become ulcerated and form furuncular lesions. In patients who have been in endemic areas, these larvae are to be suspected. Below, we present a 75-year-old male with a clinical picture of a palpable mass in the areola associated with the outflow of serohematic fluid through a central orifice. A breast intraductal lesion was suspected, so a breast ultrasound and biopsy were performed, which showed a structure compatible with myiasis. The diagnostic challenge was the high number of different diagnoses and the little knowledge of health professionals about tropical diseases.

Unexpected decadal density-dependent shifts in California sea lion size, morphology, and foraging niche.

Many marine mammal populations are recovering after long eras of exploitation.1,2 To what degree density-dependent body size declines in recovering species reflect a general response to increased resource competition is unknown. We examined skull size (as a proxy for body size), skull morphology, and foraging dynamics of the top marine predator, the California sea lion (Zalophus californianus), which have been steadily increasing over the last few decades and have approached or reached their carrying capacity in southern California.3 We show that, contrary to predictions, male California sea lions increased rather than decreased their average body size over a 46-year (1962-2008) recovery period. Larger males had proportionally longer oral cavities and more powerful bite strength, and their foraging niche expanded. Females between 1983 and 2007 maintained stable skull dimensions, but their isotopic niche was broader than contemporary males. Increased male body size is compatible with an intensification of density-dependent sexual selection for larger and more competitive individuals concurrent with an expanding foraging niche. High foraging variability among females would explain their body size stability during decades of population recovery. We demonstrate that body size reduction is not the universal response to population recovery in marine mammals and show that selective ecological dynamics could contribute to protecting populations against the increased density-dependent intraspecific competition. However, prey shifts associated with climate change will likely prevent California sea lions (and other marine mammals) from attaining these ecological dynamics, augmenting their vulnerability to resource competition and diminishing their capacity to overcome it.

Feeding morphology and body size shape resource partitioning in an eared seal community.

Body size and feeding morphology influence how animals partition themselves within communities. We tested the relationships among sex, body size, skull morphology and foraging in sympatric otariids (eared seals) from the eastern North Pacific Ocean, the most diverse otariid community in the world. We recorded skull measurements and stable carbon (δ13C) and nitrogen (δ15N) isotope values (proxies for foraging) from museum specimens in four sympatric species: California sea lions (Zalophus californianus), Steller sea lions (Eumetopias jubatus), northern fur seals (Callorhinus ursinus) and Guadalupe fur seals (Arctocephalus townsendi). Species and sexes had statistical differences in size, skull morphology and foraging significantly affecting the δ13C values. Sea lions had higher δ13C values than fur seals, and males of all species had higher values than females. The δ15N values were correlated with species and feeding morphology; individuals with stronger bite forces had higher δ15N values. We also found a significant community-wide correlation between skull length (indicator of body length), and foraging, with larger individuals having nearshore habitat preferences, and consuming higher trophic level prey than smaller individuals. Still, there was no consistent association between these traits at the intraspecific level, indicating that other factors might account for foraging variability.

New data from the first discovered paleoparadoxiid (Desmostylia) specimen shed light into the morphological variation of the genus Neoparadoxia.

Desmostylia is an extinct clade of marine mammals with two major sub-clades, Desmostylidae and Paleoparadoxiidae, known from Oligocene to Miocene strata of the North Pacific coastline. Within Paleoparadoxiidae, three genera have been identified: Archaeoparadoxia, Paleoparadoxia, and Neoparadoxia. The latter taxon is the geochronologically youngest palaeoparadoxiid and Neoparadoxia is characterized by a comparatively larger body size, although it is known only from a few specimens within a short temporal and geographic range. Here we report the discovery of an isolated tooth, which we identify as Neoparadoxia cf. N. cecilialina, constituting only the second individual specimen of Neoparadoxia with preserved dentition yet reported. This specimen was collected near Corona, California, USA, and we attribute it to the "Topanga" Formation, extending the geographic range of this taxon in Southern California. While the exact geographic locality was not recorded when it was collected in 1913, we establish two potential localities based on associated hand-written museum label and new stratigraphic information. Although initially identified as Desmostylus hesperus, this specimen of Neoparadoxia was collected 10 years before the first named paleoparadoxiid from Japan. We expect that description of more complete desmostylian material from elsewhere in Southern California will clarify the taxonomic richness and paleoecological role of this clade in Cenozoic marine mammal assemblages.

Anti-racist interventions to transform ecology, evolution and conservation biology departments.

Racial and ethnic discrimination persist in science, technology, engineering and mathematics fields, including ecology, evolution and conservation biology (EECB) and related disciplines. Marginalization and oppression as a result of institutional and structural racism continue to create barriers to inclusion for Black people, Indigenous people and people of colour (BIPOC), and remnants of historic racist policies and pseudoscientific theories continue to plague these fields. Many academic EECB departments seek concrete ways to improve the climate and implement anti-racist policies in their teaching, training and research activities. We present a toolkit of evidence-based interventions for academic EECB departments to foster anti-racism in three areas: in the classroom; within research laboratories; and department wide. To spark restorative discussion and action in these areas, we summarize EECB's racist and ethnocentric histories, as well as current systemic problems that marginalize non-white groups. Finally, we present ways that EECB departments can collectively address shortcomings in equity and inclusion by implementing anti-racism, and provide a positive model for other departments and disciplines.

Extreme dispersal or human-transport? The enigmatic case of an extralimital freshwater occurrence of a Southern elephant seal from Indiana.

Elephant seals (Mirounga spp.) are the largest living pinnipeds, and the spatial scales of their ecology, with dives over 1 km in depth and foraging trips over 10,000 km long, are unrivalled by their near relatives. Here we report the discovery of an incomplete Holocene age Southern elephant seal (M. leonina) rostrum from Indiana, USA. The surviving material are two casts of the original specimen, which was collected in a construction excavation close to the Wabash River near Lafayette, Indiana. The original specimen was mostly destroyed for radiometric dating analyses in the 1970s, which resulted in an age of 1,260 ± 90 years before the present. The existence of sediments in the original specimen suggests some type of post depositional fluvial transportation. The prevalent evidence suggests that this male Southern elephant seal crossed the equator and the Gulf of Mexico, and then entered the Mississippi River system, stranding far upriver in Indiana or adjacent areas, similar to other reported examples of lost marine mammals in freshwater systems. Based on potential cut marks, we cannot exclude human-mediated transportation or scavenging by Indigenous peoples as a contributing factor of this occurrence. The material reported here represents by far the northernmost occurrence of a Southern elephant seal in the Northern Hemisphere ever recorded. The unusual occurrence of a top marine predator >1,000 km from the closest marine effluent as a potential extreme case of dispersal emphasizes how marine invasions of freshwater systems have happened frequently through historical (and likely geological) time.

What do we know about the fossil record of pinnipeds? A historiographical investigation.

The fossil record of pinnipeds (seals, fur seals and walruses) is globally distributed, spanning from the late Oligocene to the Holocene. This record shows a complex evolutionary history that could not otherwise be inferred from their extant relatives, including multiple radiations and iterative ecomorphological specializations among different lineages, many of which are extinct. The fossil record of pinnipeds is not uniformly represented in space and time, however, leaving some gaps in our knowledge. We performed a historiographical investigation of the published fossil record of pinnipeds based on the information available in the Paleobiology Database, with the aim to broadly characterize and evaluate it from a taxonomic, geographical and temporal perspective. We identified major trends, strengths and weaknesses of the pinniped fossil record, including potential biases that may affect our interpretations. We found that 39% of the record corresponds to extant taxa, which are essentially from the Pleistocene and Holocene. There is a larger record from the Northern Hemisphere, suggesting biases in sampling and collection effort. The record is not strongly biased by sedimentary outcrop bias. Specifically, for extinct species, nearly half of them are represented by a single occurrence and a large proportion have type specimens consisting of single isolated postcranial elements. While the pinniped fossil record may have adequate temporal and taxonomic coverage, it has a strong geographical bias and its comparability is hindered by the incompleteness of type specimens. These results should be taken into account when addressing patterns of their past diversity, evolutionary history and paleoecology.

Primary hepatic carcinoid tumor metastasizing to eyelid: A case report.

PURPOSE: We report a rare case of a metastatic carcinoid tumor to the right lower lid masquerading as a chalazion. OBSERVATIONS: A 78-year-old Hispanic woman who presented with a 3-month history of a non-resolving chalazion on the right lower lid despite aggressive medical treatment. The patient had a history of noninfectious anterior uveitis and primary hepatic carcinoid tumor that was incidentally diagnosed during the initial uveitis work-up. The right lower eyelid lesion was biopsied and histological and immunopathological analysis revealed a well differentiated neuroendocrine tumor consistent with a carcinoid tumor. CONCLUSIONAND IMPORTANCE: Neuroendocrine tumors should be considered as part of the differential diagnosis of focal, vascularized eyelid masses. To the authors best knowledge this is the first reported case of primary hepatic carcinoid tumor with metastasis to the eyelids. We also highlight the importance of pursuing a histopathologic diagnosis, in the setting of a non-resolving or recurrent chalazion.

Oldest record of monk seals from the North Pacific and biogeographic implications.

True seals (crown Phocidae) originated during the late Oligocene-early Miocene (approx. 27-20 Ma) in the North Atlantic/Mediterranean region, with later (middle Miocene, approx. 16-11 Ma) dispersal events to the South Atlantic and South Pacific. Contrasting with other pinnipeds, the fossil record of phocids from the North Pacific region is scarce and restricted to the Pleistocene. Here we present the oldest fossil record of crown phocids, monachines (monk seals), from the North Pacific region. The specimens were collected from the upper Monterey Formation in Southern California and are dated to 8.5-7.1 Ma, predating the previously oldest known record by at least 7 Ma. This record provides new insights into the early biogeographic history of phocids in the North Pacific and is consistent with a northward dispersal of monk seals (monachines), which has been recognized for other groups of marine mammals. Alternatively, this finding may correspond with a westward dispersal through the Central American Seaway of some ancestor of the Hawaiian monk seal. This record increases the taxonomic richness of the Monterey pinniped assemblage to five taxa, making it a fairly diverse fossil assemblage, but also constitutes the oldest record of sympatry among all three extant pinniped crown clades.

Desenlaces con dos técnicas de sutura hemostática uterina en pacientes con hemorragia obstétrica / Results with two techniques of uterine hemostatic sutures in obstetric hemorrhage patients

Resumen OBJETIVO: Exponer los desenlaces de dos técnicas de sutura hemostática uterina para controlar la hemorragia obstétrica. MATERIALES Y MÉTODOS: Estudio prospectivo, observacional y longitudinal, llevado a cabo en tres unidades hospitalarias de Guanajuato, México, del 1 de enero al 30 de noviembre de 2018. Se incluyeron pacientes con hemorragia transcesárea y posparto. En las primeras se aplicó la técnica de B-Lynch y en las segundas la de Hayman. Se analizaron las variables: 1) cantidad de hemorragia antes y después de aplicar la sutura, 2) tiempo del procedimiento, 3) concentración de hemoglobina al ingreso a la unidad de atención, 1 hora después de la hemorragia y 24 horas posteriores a la intervención quirúrgica, 4) desenlace de las técnicas y 5) complicaciones. Para el análisis de los datos se utilizó el programa SPSS versión 22 para Windows. RESULTADOS: Se registraron 34 pacientes: 26 con aplicación de la técnica de sutura B-Lynch y 8 con la técnica de Hayman. La pérdida sanguínea después de la aplicación de las técnicas fue menor (p < 0.001). El tiempo entre el diagnóstico de hemorragia y la aplicación de la sutura fue de 11.5 ± 5.9 minutos. La concentración de hemoglobina al ingreso al hospital y 1 h posterior a la hemorragia fue significativamente menor (p < 0.01) versus 24 h después (p < 0.05) 30 de 34 pacientes tuvieron reacción favorable al tratamiento quirúrgico. Cuatro mujeres requirieron procedimientos adicionales para el control de la hemorragia. No se reportaron complicaciones ni muertes maternas asociadas con las técnicas de sutura. CONCLUSIONES: Las técnicas de sutura uterina representan un procedimiento útil, rápido y sin complicaciones para el control de la hemorragia obstétrica.

Abstract OBJECTIVE: To present the results obtained with two techniques of uterine hemostatic sutures for the control of obstetric hemorrhage. MATERIALS AND METHODS: Prospective, observational, longitudinal study in three hospital units of the 1st. from January to November 30, 2018. Thirty-four patients with postpartum and transcesarean hemorrhage were included. The postpartum patients underwent Hayman technique and the B-Lynch technique. The following were analyzed: 1) amount of hemorrhage before and after the sutures, 2) time between diagnosis and placement, 3) hemoglobin levels at admission to the care unit, 1 hour after the hemorrhage and 24 hours after treatment, 4) results with the two techniques and 5) complications. Statistical analysis of all these variables was performed with SPSS, 22 version. RESULTS: A total of 34 patients were registered: 26 sutures performed with B-Lynch technique and 8 with Hayman technique. The amount of bleeding after the application was lower (p <0.001). The time between diagnosis of bleeding and placement was 11.5 + 5.9 minutes. The hemoglobin levels at admission to the hospital and one hour after the hemorrhage were significantly lower (p <0.01) and 24 hours later (p <0.05). In 30/34 of cases, a favorable response to surgical treatment was achieved. In four cases, another procedure was required to control bleeding. There were no complications with the use of sutures or maternal deaths. CONCLUSIONS: The use of uterine sutures was a useful, fast and uncomplicated therapy for the control of obstetric hemorrhage.

Lupus erythematosus tumidus in childhood treated with antimalarials / Lupus eritematoso tumidus en la infancia tratado con antimalárico

Abstract Lupus erythematosus tumidus is a rare dermatosis. It is considered a subtype of chronic cutaneous lupus erythematosus of uncertain pathogenesis, favorable prognosis and rare association with systemic lupus erythematosus. Clinically, it manifests as urticarial-like plaques in photo exposed areas, mainly affecting adults, being extremely rare in pediatric age. Herein, we present two cases of six and nine-year-old male patients with clinical and histological characteristics typical of lupus erythematosus tumidus and poor response to first-line treatment (topical, intralesional steroids and topical calcineurin inhibitors); therefore, it was decided to start systemic therapy with antimalarials, obtaining a very good response.

Resumen El lupus eritematoso tumidus es una dermatosis poco frecuente. Es considerada una variante del lupus eritematoso cutáneo crónico, de patogénesis incierta, pronóstico favorable y rara asociación con lupus eritematoso sistémico. Clínicamente, se manifiesta como placas de aspecto urticarial en zonas fotoexpuestas, que principalmente afectan a los adultos, siendo extremadamente rara en edad pediátrica. A continuación presentamos dos casos de pacientes de sexo masculino de seis y nueve años, con características clínicas e histológicas típicas de lupus eritematoso tumidus y poca respuesta al tratamiento de primera línea (esteroides tópicos, intralesionales e inhibidores de calcineurina tópica), por lo que se decidió iniciar manejo sistémico con antimalárico, obteniendo muy buena respuesta terapéutica.

Incorporación del mindfulness en el aula: un estudio piloto con estudiantes universitarios / Mindfulness Classroom Implementation: A Pilot Study with University Students

Resumen El objetivo del estudio fue analizar los efectos de un programa breve de mindfulness adaptado al contexto del aula, en relación con el nivel de mindfulness (MAAS), evitación experiencial (AAQ-II), ansiedad (STAI) y satisfacción vital (SWLS). La muestra estuvo conformada por 115 estudiantes universitarios. Tras la participación en el programa, los estudiantes aumentaron significativamente los niveles de satisfacción vital y ansiedad estado, no se encontraron diferencias en el resto de variables. Sin embargo, el aumento de la satisfacción vital se relacionó con el aumento del nivel de mindfulness al final del programa (coincidiendo con el inicio de los exámenes). En conclusión, un programa breve de mindfulness mejora la satisfacción vital, aun en un período de alto nivel de ansiedad como es el periodo de exámenes.

Abstract The aim of this pilot study was to analyze the effects of a brief mindfulness program adapted to the academic context, to acknowledge the influence on the level of mindfulness (MAAS), experiential avoidance (AAQ-II), anxiety (STAI) and life satisfaction (SWLS). The sample consisted of 115 college students. After participating in the programme, students showed significantly higher levels of life satisfaction and state anxiety and no differences were found in mindfulness, experiential avoidance and trait anxiety. However, the increase in life satisfaction was related to the increased level of mindfulness at the end of the program (which concurred with the beginning of the exams). In conclusion, a brief mindfulness program improved life satisfaction even in a period of high anxiety, such as the exams period.

Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom.

While large mass mortality events (MMEs) are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behavior. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions, such as harmful algal blooms (HABs). In Southern Chile, HABs can be triggered by the ocean-atmosphere phenomenon El Niño. The frequency of the strongest El Niño events is increasing due to climate change. In March 2015, by far the largest reported mass mortality of baleen whales took place in a gulf in Southern Chile. Here, we show that the synchronous death of at least 343, primarily sei whales can be attributed to HABs during a building El Niño. Although considered an oceanic species, the sei whales died while feeding near to shore in previously unknown large aggregations. This provides evidence of new feeding grounds for the species. The combination of older and newer remains of whales in the same area indicate that MMEs have occurred more than once in recent years. Large HABs and reports of marine mammal MMEs along the Northeast Pacific coast may indicate similar processes in both hemispheres. Increasing MMEs through HABs may become a serious concern in the conservation of endangered whale species.

[Assessment of negative stereotypes about old age in young people and adults]. / Evaluación de los estereotipos negativos hacia la vejez en jóvenes y adultos.

INTRODUCTION: Negative stereotypes towards ageing and the old age may negatively influence relationships and working with older people. The CENVE (Negative Stereotypes Towards Ageing) questionnaire is a validated Spanish tool designed to evaluate these stereotypes, but there are no evidence about its factorial structure with young people and adults. This factorial structure of CENVE is analysed in non-elderly subjects, and its relationship with various sociodemographic and experience-related indicators is also examined. METHOD: A total of 350 young people and adults completed the CENVE. Information on demographics, specialised academic training in aging, and level of contact with elderly people were also provided. An analysis was performed on the factorial structure of the questionnaire and its relationship with socio-demographic and experiential indicators. RESULTS: The analyses performed did not confirm the original structure in 3 sub-scales, suggesting an alternative one-dimensional structure. It also suggested the existence of different ageist stereotypes associated with the socio-demographic profile of non-elderly subjects (particularly related to educational level). Less conclusive results were obtained regarding former experience and level of information on aging. CONCLUSIONS: CENVE is a useful tool for evaluating ageism, but in the present article a one-dimensional correction is suggested for the non-elderly population.

Granzyme B mediates both direct and indirect cleavage of extracellular matrix in skin after chronic low-dose ultraviolet light irradiation.

Extracellular matrix (ECM) degradation is a hallmark of many chronic inflammatory diseases that can lead to a loss of function, aging, and disease progression. Ultraviolet light (UV) irradiation from the sun is widely considered as the major cause of visible human skin aging, causing increased inflammation and enhanced ECM degradation. Granzyme B (GzmB), a serine protease that is expressed by a variety of cells, accumulates in the extracellular milieu during chronic inflammation and cleaves a number of ECM proteins. We hypothesized that GzmB contributes to ECM degradation in the skin after UV irradiation through both direct cleavage of ECM proteins and indirectly through the induction of other proteinases. Wild-type and GzmB-knockout mice were repeatedly exposed to minimal erythemal doses of solar-simulated UV irradiation for 20 weeks. GzmB expression was significantly increased in wild-type treated skin compared to nonirradiated controls, colocalizing to keratinocytes and to an increased mast cell population. GzmB deficiency significantly protected against the formation of wrinkles and the loss of dermal collagen density, which was related to the cleavage of decorin, an abundant proteoglycan involved in collagen fibrillogenesis and integrity. GzmB also cleaved fibronectin, and GzmB-mediated fibronectin fragments increased the expression of collagen-degrading matrix metalloproteinase-1 (MMP-1) in fibroblasts. Collectively, these findings indicate a significant role for GzmB in ECM degradation that may have implications in many age-related chronic inflammatory diseases.

Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea.

Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.

Neuropsychological function, anxiety, depression and pain impact in fibromyalgia patients.

Cognitive deficits have a significant impact on the daily performance of fibromyalgia patients. This paper analyzes executive functioning and decision-making performance, and the relationships between these functions and pain, anxiety, depression and medication in fibromyalgia patients. A group of fibromyalgia patients (FG) (n = 85) was compared with a healthy control group (CG) (n = 85) in their performance in the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Task (IGT). In the WCST, results showed a percentage of non-perseverative errors significantly higher in the CG than in the FG (p = .026), the other variables (percentage of perseverative errors, number of categories and failures to maintain set) showed no significant differences. In relation to decision-making (IGT), once the rules had been learnt, the FG made fewer advantageous choices than the CG, but these differences were not statistically significant (p = .325). In the FG, pain severity (p = .010) and impact on daily activities (p = .016) interfered with decision-making, unlike anxiety, depression or medication, which did no relate to it. In executive function, pain and impact on daily activities were associated with the percentage of perseverative errors (p = .051) and the number of categories (p = .031), whereas pain severity was related to failures to maintain set (p = .039), indicative of increased distractibility and poor attentional ability. In conclusion, FG showed normal performance in executive functioning and decision-making. Moreover, pain was associated with neuropsychological functioning whereas anxiety, depression and medication were not.

Enfoque y manejo de cicatrices hipertróficas y queloides / Approach and management of hypertrophic scars and keloids

La cicatrización es un proceso dinámico, continuo y complejo en el que interactúan diferentes células, la matriz extracelular y mediadores químicos, como citocinas, además de la influencia de factores locales y sistémicos. El proceso se lleva a cabo en tres pasos secuenciales que incluyen la fase inflamatoria y de hemostasia, la fase de proliferación y, finalmente, la fase de maduración y remodelación de la cicatriz. Las cicatrices hipertróficas y queloides hacen parte del espectro de cicatrices anormales; su fisiopatología no es clara pero se proponen diversas teorías que se discuten en este artículo. Además, se aborda un enfoque práctico para su manejo teniendo en cuenta las opciones terapéuticas disponibles en nuestro medio así como los manejos experimentales.

Síndrome de Sturge-Weber tratado con láser de colorante pulsado / Sturge-Weber syndrome treated with 589 nm pulsed dye laser

El síndrome de Sturge-Weber es un trastorno neurocutáneo congénito, esporádico, que se manifiesta con malformación capilar facial, angiomatosis leptomeníngea y angiomas coroideos que predisponen a glaucoma. Para el manejo de la malformación capilar facial, el láser de colorante pulsado es el que ha demostrado mayor eficacia. Presentamos el caso de una niña con síndrome de Sturge-Weber, tratada con láser de colorante pulsado, con muy buenos resultados estéticos.

Histiocitosis de células de Langerhans / Langerhans cell histiocytosis

La histiocitosis de células de Langerhans es una proliferación clonal anormal de células con un inmunofenotipo positivo para S-100, CD1a y presencia de gránulos de Birbeck en el citoplasma. Se caracteriza por manifestaciones clínicas variables desde una enfermedad multisistémica aguda con alta mortalidad hasta una forma crónica de curso más benigno. Se presenta una revisión sobre la fisiopatología, hallazgos clínicos y algunos conceptos importantes acerca del diagnóstico y tratamiento de las histiocitosis.