Principales tipos de quistes en dermatopatología: Parte 2 / Main Types of Cysts in Dermatopathology: Part 2

Este es el segundo artículo de una serie de dos publicados en esta revista, en los que examinamos las características histopatológicas, así como el diagnóstico diferencial, de las principales entidades que se presentan en forma de estructuras quísticas y pseudoquísticas en la biopsia cutánea. En este segundo artículo, abordamos los quistes cutáneo ciliado, branquial, de Bartholino, onfalomesentérico, tímico, del conducto tirogloso, sinovial, y del rafe medio, así como el mucocele, el ganglión y los pseudoquistes auricular y mixoide digital. (AU)

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts. (AU)

[Main Types of Cysts in Dermatopathology: Part 2]. / Principales tipos de quistes en dermatopatología: Parte 2.

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts.

Principales tipos de quistes en dermatopatología: parte 1 / Main Types of Cysts in Dermatopathology: Part 1

Las estructuras quísticas son uno de los hallazgos más frecuentes en dermatopatología. Se trata de tumores quísticos y de pseudoquistes por acumulación de ciertas sustancias, por ejemplo, mucina. En una serie de dos artículos (de los cuales este es el primero) hemos revisado los principales tipos de quistes y pseudoquistes que pueden verse en la biopsia cutánea, examinando sus aspectos histopatológicos y los principales diagnósticos diferenciales. En esta primera parte, se abordan los quistes infundibulares, dermoides, vellosos eruptivos, foliculares pigmentados, pilonidales, tricolemales, de milium, híbridos y broncogénicos, así como el esteatocistoma, el hidrocistoma y los comedones. (AU)

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones. (AU)

Principales tipos de quistes en dermatopatología: parte 1 / Main Types of Cysts in Dermatopathology: Part 1

Las estructuras quísticas son uno de los hallazgos más frecuentes en dermatopatología. Se trata de tumores quísticos y de pseudoquistes por acumulación de ciertas sustancias, por ejemplo, mucina. En una serie de dos artículos (de los cuales este es el primero) hemos revisado los principales tipos de quistes y pseudoquistes que pueden verse en la biopsia cutánea, examinando sus aspectos histopatológicos y los principales diagnósticos diferenciales. En esta primera parte, se abordan los quistes infundibulares, dermoides, vellosos eruptivos, foliculares pigmentados, pilonidales, tricolemales, de milium, híbridos y broncogénicos, así como el esteatocistoma, el hidrocistoma y los comedones. (AU)

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones. (AU)

[Main Types of Cysts in Dermatopathology: Part 1]. / Principales tipos de quistes en dermatopatología: parte 1.

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones.

Gastric metaplasia as a precursor of nonconventional dysplasia in inflammatory bowel disease.

Gastric metaplasia in colonic mucosa with inflammatory bowel disease (IBD) develops as an adaptation mechanism. The association between gastric metaplasia and nonconventional and/or conventional dysplasia as precursors of colitis-associated colorectal cancer is unknown. To address this question, we retrospectively reviewed a series of 33 IBD colectomies to identify gastric metaplasia in 76 precursor lesions. We obtained 61 nonconventional and 15 conventional dysplasias. Among nonconventional dysplasia, 31 (50.8 %) were low-grade (LGD), 4 (6.5 %) were high-grade (HGD), 9 (14.8 %) had both LGD and HGD, and 17 (27.9 %) had no dysplasia (ND), while 14 (93 %) conventional dysplasias had LGD, and 1 (7 %) had LGD and HGD. Gastric metaplasia was assessed by concomitant immunoexpression of MUC5AC and loss of CDX2 staining. Expression of a p53-mut pattern was considered as a surrogate for gene mutation, and complete loss of MLH1 staining as presence of MLH1 hypermethylation. In nonconventional dysplasia, MUC5AC immunoexpression decreased as the degree of dysplasia increased, being 78 % in LGD and 39 % in HGD (p = 0.006). CDX2 was lost in epithelial glands with high expression of MUC5AC (p < 0.001). The p53-mut pattern was observed in 77 % HGD, 45 % LGD, and in 6 % with ND (p < 0.001). Neither nonconventional nor conventional dysplasia showed complete loss of MLH1 staining. Gastric metaplasia was also present in mucosa adjacent to nonconventional dysplasia with chronic changes or active inflammation. Our results show that gastric metaplasia appears in IBD-inflamed colon mucosa, it is the substrate of most nonconventional dysplasia and occurs prior to p53 alterations.

Fast-Growing Frontal Subcutaneous Nodule in a Young Woman.

A woman in her 20s presented with a firm, mobile, painful, fast-growing subcutaneous nodule in the glabella. What is your diagnosis?

Spanish cohort of VEXAS syndrome: clinical manifestations, outcome of treatments and novel evidences about UBA1 mosaicism.

BACKGROUND: The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants. OBJECTIVES: To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines. METHODS: Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex. RESULTS: Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease. CONCLUSION: Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms.

Pancreatic panniculitis revisited: A series of 34 patients.

BACKGROUND: Pancreatic panniculitis is a rare form of panniculitis generally associated with acute or chronic pancreatitis, and less frequently with pancreatic carcinoma. Clinically, it presents with subcutaneous nodules usually located in the lower extremities, however, it presents an almost pathognomonic histopathological finding with enzymatic fat necrosis in the adipose tissue. METHODS: In this retrospective case series of five hospitals, biopsy specimens of cutaneous lesions of pancreatic panniculitis were reviewed. Clinical information was obtained through medical records. RESULTS: A total of 34 cases were included, 23 women and 11 men, aged between 31 and 92 years. The most common associated pancreatic disease was acute pancreatitis (23 cases) and its main triggering cause was gallstones (17 cases). In two patients it was related to chronic pancreatitis and six cases were associated with malignancy. Histopathological findings were always the key to diagnosis. In the biopsies reviewed, mostly lobular panniculitis with the characteristic necrosis of the adipocytes was observed. In addition, nine of the cases presented with Splendore-Hoeppli phenomenon. CONCLUSIONS: We present the largest series of pancreatic panniculitis. Clinically, the female predominance and biliary lithiasis as the main cause of acute pancreatitis are to be emphasized. Histopathologically, a peripheral eosinophilic striated rim surrounding aggregates of ghost adipocytes consistent with Splendore-Hoeppli is an additional clue to its diagnosis.

Hemosiderotic Xanthelasmas. A New Clinicopathological Variant of Xanthelasma Palpebrarum or a Localized Variant of Xanthosiderohistiocytosis of the Eyelids?

ABSTRACT: Xanthelasma palpebrarum represent the most common subtype of cutaneous plane xanthomas. Xanthosiderohistiocytosis is considered a rare variant of xanthoma disseminatum, with only 4 cases reported to date. We report the case of a man with progressive pigmented lesions on the 4 eyelids that could correspond to hemosiderotic xanthelasmas or a localized variant of xanthosiderohistiocytosis.

Alterations in p53, Microsatellite Stability and Lack of MUC5AC Expression as Molecular Features of Colorectal Carcinoma Associated with Inflammatory Bowel Disease.

Colitis-associated colorectal carcinoma (CAC) occurs in inflammatory bowel disease (IBD) because of the "chronic inflammation-dysplasia-cancer" carcinogenesis pathway characterized by p53 alterations in the early stages. Recently, gastric metaplasia (GM) has been described as the initial event of the serrated colorectal cancer (CRC) process, resulting from chronic stress on the colon mucosa. The aim of the study is to characterize CAC analyzing p53 alterations and microsatellite instability (MSI) to explore their relationship with GM using a series of CRC and the adjacent intestinal mucosa. Immunohistochemistry was performed to assess p53 alterations, MSI and MUC5AC expression as a surrogate for GM. The p53 mut-pattern was found in more than half of the CAC, most frequently stable (MSS) and MUC5AC negative. Only six tumors were unstable (MSI-H), being with p53 wt-pattern (p = 0.010) and MUC5AC positive (p = 0.005). MUC5AC staining was more frequently observed in intestinal mucosa, inflamed or with chronic changes, than in CAC, especially in those with p53 wt-pattern and MSS. Based on our results, we conclude that, as in the serrated pathway of CRC, in IBD GM occurs in inflamed mucosa, persists in those with chronic changes and disappears with the acquisition of p53 mutations.

Adalimumab Biosimilar-Induced Autoimmunity-Related Sweet-Like Neutrophilic Dermatosis.

ABSTRACT: Antitumor necrosis factor therapies have shown to produce a broad range of cutaneous eruptions. We report the case of a patient under adalimumab biosimilar treatment for a punctate inner choroidopathy who developed a cutaneous eruption on sun-exposed areas that showed a diffuse dermal neutrophilic infiltrate consistent with a Sweet-like neutrophilic dermatosis and some features of autoimmunity.

Dermatopathology of COVID-19 infection and vaccination.

BACKGROUND: Many peculiar skin changes have been described in relation to both coronavirus disease 2019 (COVID-19) infection and vaccination. OBJECTIVE: This paper provides an overview of these dermatologic manifestations, focusing on their dermatopathological appearances. RESULTS: Most COVID-19 patients develop variegated maculopapular eruptions with a combination of histological patterns commonly including keratinocyte apoptosis and eosinophilia. Urticaria-like lesions often show a combination of spongiotic and lichenoid patterns and are more frequent in individuals with severe disease. Vesicular lesions can be disseminated; in some cases, they become pustular and in others show dyskeratosis and a peculiar form of ballooning. Some patients develop vesicular Grover disease on the trunk. Young patients with a strong immunological response can eliminate the virus easily but may develop chilblains as a consequence of the high interferon response. Conversely, older individuals with immunosenescence and a tendency toward hypercoagulability can present livedoid and ischemic areas. Regarding COVID-19 vaccination, hypersensitivity reactions are most frequent, including "COVID-arm." Nonetheless, a combination of local and systemic cutaneous manifestations (reactogenicity) is commonly seen. Histopathologically, lichenoid and spongiotic changes and a variable number of eosinophils are typical of rashes characterized by papules and plaques. Other dermatological side effects of COVID-19 vaccination include lesions mimicking well-defined dermatoses such as lichen planus or bullous pemphigoid and triggering of collagenous diseases. CONCLUSION: Well-characterized skin manifestations of coronavirus disease 2019 (COVID-19) include chilblains, livedo necrotic lesions, vesicular eruptions, urticarial lesions, and maculopapular eruptions. Hypersensitivity reactions are common after SARS-CoV­2 mRNA vaccination. Vaccine reactions may also mimic other dermatosis such as bullous pemphigoid or lichen planus, stimulate herpes reactivation, or trigger the development of autoimmune diseases.

Safety and Feasibility of Transbronchial Cryobiopsy in Mechanically Ventilated Patients

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