International Journal of DermatologyEarly View Letter to the Editor Treatment of central centrifugal cicatricial alopecia with topical metformin 10% cream: case report and literature review Bárbara Vieira Granja, Corresponding Author Bárbara Vieira Granja [email protected] orcid.org/0000-0002-9032-787X Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this authorPedro Rolo De Matos, Pedro Rolo De Matos orcid.org/0000-0002-4208-7939 Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorGilberto Pires Rosa, Gilberto Pires Rosa Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal RISE@CINTESIS, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this authorJorge Pinheiro, Jorge Pinheiro Department of Pathology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorFilomena Azevedo, Filomena Azevedo Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorAna Filipa Pedrosa, Ana Filipa Pedrosa Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal RISE@CINTESIS, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this author Bárbara Vieira Granja, Corresponding Author Bárbara Vieira Granja [email protected] orcid.org/0000-0002-9032-787X Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this authorPedro Rolo De Matos, Pedro Rolo De Matos orcid.org/0000-0002-4208-7939 Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorGilberto Pires Rosa, Gilberto Pires Rosa Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal RISE@CINTESIS, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this authorJorge Pinheiro, Jorge Pinheiro Department of Pathology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorFilomena Azevedo, Filomena Azevedo Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, PortugalSearch for more papers by this authorAna Filipa Pedrosa, Ana Filipa Pedrosa Department of Dermatology and Venereology, Unidade Local de Saúde São João, Porto, Portugal RISE@CINTESIS, Faculty of Medicine, University of Porto, Porto, PortugalSearch for more papers by this author First published: 23 June 2024 https://doi.org/10.1111/ijd.17345 Conflict of interest: None. Funding source: None. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1Lawson CN, Bakayoko A, Callender VD. Central centrifugal cicatricial alopecia: challenges and treatments. Dermatol Clin. 2021; 39: 389–405. 10.1016/j.det.2021.03.004 CASPubMedWeb of Science®Google Scholar 2Aguh C, Dina Y, Talbot CC Jr, Garza L. Fibroproliferative genes are preferentially expressed in central centrifugal cicatricial alopecia. J Am Acad Dermatol. 2018; 79: 904–912.e1. 10.1016/j.jaad.2018.05.1257 CASPubMedWeb of Science®Google Scholar 3Wu M, Xu H, Liu J, Tan X, Wan S, Guo M, et al. Metformin and fibrosis: a review of existing evidence and mechanisms. J Diabetes Res. 2021; 2021:6673525. 10.1155/2021/6673525 PubMedWeb of Science®Google Scholar 4Markowicz-Piasecka M, Huttunen KM, Mateusiak L, Mikiciuk-Olasik E, Sikora J. Is metformin a perfect drug? Updates in pharmacokinetics and pharmacodynamics. Curr Pharm Des. 2017; 23: 2532–2550. 10.2174/1381612822666161201152941 CASPubMedWeb of Science®Google Scholar 5Araoye EF, Thomas JAL, Aguh CU. Hair regrowth in 2 patients with recalcitrant central centrifugal cicatricial alopecia after use of topical metformin. JAAD Case Rep. 2020; 6: 106–108. 10.1016/j.jdcr.2019.12.008 PubMedGoogle Scholar Early ViewOnline Version of Record before inclusion in an issue ReferencesRelatedInformation

Medulloblastoma (MB) is the most prevalent malignant brain tumor in children, known for its heterogeneity and treatment-associated toxicity, and there is a critical need for new therapeutic targets. We analyzed the somatic mutation profile of 15 driver genes in 69 Latin-Iberian molecularly characterized medulloblastomas using the Illumina TruSight Tumor 15 panel. We classified the variants based on their clinical impact and oncogenicity. Among the patients, 66.7% were MBSHH, 13.0% MBWNT, 7.3% MBGrp3, and 13.0% MBGrp4. Among the 63 variants found, 54% were classified as Tier I/II and 31.7% as oncogenic/likely oncogenic. We observed 33.3% of cases harboring at least one mutation. TP53 (23.2%, 16/69) was the most mutated gene, followed by PIK3CA (5.8%, 4/69), KIT (4.3%, 3/69), PDGFRA (2.9%, 2/69), EGFR (1.4%, 1/69), ERBB2 (1.4%, 1/69), and NRAS (1.4%, 1/69). Approximately 41% of MBSHH tumors exhibited mutations, TP53 (32.6%) being the most frequently mutated gene. Tier I/II and oncogenic/likely oncogenic TP53 variants were associated with relapse, progression, and lower survival rates. Potentially actionable variants in the PIK3CA and KIT genes were identified. Latin-Iberian medulloblastomas, particularly the MBSHH, exhibit higher mutation frequencies than other populations. We corroborate the TP53 mutation status as an important prognostic factor, while PIK3CA and KIT are potential therapeutic targets.

Calcifying odontogenic cysts (COCs) exhibit a diverse clinical course, commonly developing between the second and third decades of life, displaying no gender predilection. A 15-year-old female without medical history was under observation for a mixed lesion in the maxilla associated with an impacted tooth. She presented to the emergency department with sudden onset and worsening swelling of the left midface. Radiographic findings in the panoramic radiograph and a CT scan revealed a well-circumscribed mixed lesion localized in the left maxilla, extending into the left maxillary sinus and reaching the orbital floor. After an intercurrent infection of the cyst, the patient was hospitalized, received intravenous antibiotics, and went for surgical intervention under general anesthesia. Lesions that combine histological characteristics of two or more odontogenic tumors or individual cysts in the same location are called hybrid odontogenic lesions. This type of lesion poses a challenge for both pathologists and surgeons, because of its controversial histogenesis and poorly understood clinical evolution. The most common of these lesions are COCs associated with odontoma. Our case represents an exceptionally rare entity among odontogenic cysts.

Pediatric brain tumors (PBT) are the leading cause of non-accidental death in pediatric age. These tumors are rare and lack adequate experimental models capable of accurately capturing their complex molecular landscape. Our team has established specific protocols for the generation and expansion of ex-vivo patient-derived organoids (PDO) from fresh surgical material of a variety of PBT, within a clinically relevant timeframe. These include pilocytic astrocytomas, a pleomorphic xanthoastrocytoma, a rosette-forming glioneuronal tumor, a supratentorial ependymoma, diffuse high-grade gliomas, a medulloblastoma, an atypical teratoid rhabdoid tumor, and a meningioma. The PDO cultures were set within 7-15 days, with organoids reaching 200-800 μm in diameter. Immunofluorescence analysis using confocal high-content microscopy imaging revealed that PDO kept the protein markers typically found in the corresponding primary tumors. Likewise, at a genomic level, PDO recapitulated the molecular landscape of corresponding primary tumors, as denoted by the maintenance of NF1, PIK3CA, and FGFR1mutations (rosette-forming glioneuronal tumor), KIAA1549::BRAF fusions (pilocytic astrocytomas), ZFTA::RELA fusion(supratentorial ependymoma) or gene amplifications, such as KRAS, CDK4, MDM2, GLI1, PTPN11 and PI3KCA. Additionally, PDO exhibited minimal genetic drift after over one month in culture. In three PBT cases from a medulloblastoma, an atypical teratoid rhabdoid tumor, and a meningioma, where no molecular alterations were detected using a comprehensive NGS panel, we are running DNA methylation arrays and copy number variations. Our results underscore the potential of PDO as a robust ex-vivo experimental model. The generated PDO cultures can be rapidly established and retain key molecular features of corresponding primary tumors. This preclinical model presents versatile applications, serving as a valuable molecular tool for precision medicine approaches in PBT patients, the study of PBT biology, and the acceleration of drug development processes within the context of PBT.

A 40-year-old male with no previous medical history presented to emergency department with a 2-week history of progressive dyspnea. He also described night sweats and weight loss (15 kg) during the last 3 months. Thoraco-abdominal computed tomography showed multiple bilateral lung nodules associated with supra-clavicular, hilar and peri-esophageal lymphadenopathies and gastric parietal thickening. These imaging features were suggestive of primary gastric cancer with lung and lymph node metastases. Therefore, he undergone upper digestive endoscopy that showed a large ulcerated protruding lesion at the greater curvature of the body suggestive of malignancy. Gastric biopsies of the lesion confirmed a solid neoplasia constituted by solid nests and sheets of highly pleomorphic, bizarre cells with cytotrophoblastic and syncytiotrophoblastic differentiation that, on immunohistochemistry, stained positive for β-HCG, SALL-4 and glypican-3. CT-guided biopsy of lung nodules revealed malignant cells with similar histopathological and immunohistochemical features. Elevated serum alpha-fetoprotein and β-HCG were also detected. Clinical and ultrasound examination were negative for testicular masses. These findings were consistent with a primary gastric choriocarcinoma presenting with lung and lymph node metastases (stage IV). Although chemotherapy was started, the patient evolved unfavorably and died after 9 months. Primary gastric choriocarcinoma is a rare and aggressive gastrointestinal malignancy. This case demonstrates its rapid growth rate and high metastatic potential that may lead to symptoms from secondary involvement of distant organs.

PurposeMedulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%–90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics.MethodsA total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively.ResultsWNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants.ConclusionWe observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.

BACKGROUND AND AIM:Amyloidosis is a systemic disease characterized by extracellular deposition of amyloid protein, most commonly in the heart and kidney. Hepatic amyloidosis is a rare form of presentation that ranges from mild hepatomegaly and altered liver biochemical tests to acute liver failure. The aims of this study were to evaluate the prevalence of amyloidosis in patients undergoing liver biopsy and describe its main clinical characteristics and prognostic impact. METHODS:A retrospective analysis of all patients with a histological diagnosis of hepatic amyloidosis between January 2010 and December 2019 was performed. MAJOR RESULTS:A total of 7 patients were identified from a total of 1773 liver biopsy procedures (0.4%), with a female predominance (6/7) and median age of diagnosis of 62 years. The most common clinical manifestations included hepatomegaly (4/7), jaundice (2/7) and peripheral edema (2/7), whereas 3/7 patients were asymptomatic. Every patient presented abnormalities in liver biochemical tests, more commonly cholestasis (6/7), but also cytolysis (4/7) or hyperbilirubinemia (2/7). Abnormal imaging findings included hepatomegaly, steatosis or parenchymal heterogeneity. In most patients (5/7), other organs were involved, most commonly with nephrotic syndrome (3/7) and infiltrative cardiomyopathy (3/7). The most common type was AA amyloidosis (3/7) followed by AL amyloidosis (2/7). The 1-year mortality rate was 43% and the median survival was 24 months. CONCLUSIONS:We report a low prevalence (0.4%) of amyloidosis among patients undergoing liver biopsy. Although rare, hepatic amyloidosis is associated with a dismal prognosis and a high index of suspicion is crucial to achieve an early diagnosis. .

A high-fat (HF) diet reduces resistance to the foodborne pathogen Listeria monocytogenes. We demonstrate that short-term gavage with A. muciniphila increases resistance to oral and systemic L. monocytogenes infection in mice fed a HF diet. A. muciniphila reduced inflammation in the gut and liver of mice fed a high-fat diet prior to infection and reduced inflammatory cell infiltration in the ileum to levels similar to mice fed a low-fat (LF) diet. Akkermansia administration had minimal impacts upon the microbiota and microbial metabolites and did not affect individual taxa or impact the Bacteroidetes to Firmicutes ratio. In summary, A. muciniphila increased resistance to L. monocytogenes infection in mice fed a HF diet by moderating immune/physiological effects through specific interaction between A. muciniphila and the host gut.

Glioblastoma (GB) is one of the deadliest human cancers. Many GB patients do not respond to treatment, and inevitably die within a median of 15-18 months post-diagnosis, highlighting the need for reliable biomarkers to aid clinical management and treatment evaluation. The GB microenvironment holds tremendous potential as a source of biomarkers; several proteins such as MMP-2, MMP-9, YKL40, and VEGFA have been identified as being differentially expressed in GB patient samples. Still to date, none of these proteins have been translated into relevant clinical biomarkers. This study evaluated the expression of MMP-2, MMP-9, YKL40, and VEGFA in a series of GBs and their impact on patient outcome. High levels of VEGFA expression were significantly associated with improved progression-free survival after bevacizumab treatment, thus having potential as a tissue biomarker for predicting patients' response to bevacizumab. Noteworthily, VEGFA expression was not associated with patient outcome after temozolomide treatment. To a lesser extent, YKL40 also provided significant information regarding the extent of bevacizumab treatment. This study highlights the importance of studying secretome-associated proteins as GB biomarkers and identifies VEGFA as a promising marker for predicting response to bevacizumab.

A 51-year-old male with previous medical history of dyslipidemia performed screening colonoscopy, which revealed a sessile polypoid lesion with a diameter of approximately 8 mm located at the proximal transverse colon, which was resected en bloc with a cold snare. Remarkably, histopathological examination revealed a proliferation of spindle cells in the lamina propria entrapping colonic crypts without evidence of nuclear pleomorphism, mitotic figures or necrosis. On immunohistochemistry, spindle cells were diffusely positive for glucose transporter-1 and negative for S100, DOG1, CD34 and smooth muscle actin. These features were consistent with a diagnosis of colonic perineurioma.

Paige Prostate is a clinical-grade artificial intelligence tool designed to assist the pathologist in detecting, grading, and quantifying prostate cancer. In this work, a cohort of 105 prostate core needle biopsies (CNBs) was evaluated through digital pathology. Then, we compared the diagnostic performance of four pathologists diagnosing prostatic CNB unaided and, in a second phase, assisted by Paige Prostate. In phase 1, pathologists had a diagnostic accuracy for prostate cancer of 95.00%, maintaining their performance in phase 2 (93.81%), with an intraobserver concordance rate between phases of 98.81%. In phase 2, pathologists reported atypical small acinar proliferation (ASAP) less often (about 30% less). Additionally, they requested significantly fewer immunohistochemistry (IHC) studies (about 20% less) and second opinions (about 40% less). The median time required for reading and reporting each slide was about 20% lower in phase 2, in both negative and cancer cases. Lastly, the average total agreement with the software performance was observed in about 70% of the cases, being significantly higher in negative cases (about 90%) than in cancer cases (about 30%). Most of the diagnostic discordances occurred in distinguishing negative cases with ASAP from small foci of well-differentiated (less than 1.5 mm) acinar adenocarcinoma. In conclusion, the synergic usage of Paige Prostate contributes to a significant decrease in IHC studies, second opinion requests, and time for reporting while maintaining highly accurate diagnostic standards.

Aim: Vibrio harveyi is a Gram-negative marine bacterium that is a model system in the study of quorum sensing (QS). V. harveyi uses multichannel QS, mediated by three signaling molecules. The aim of this study was to synthesize and screen a diverse series of furanones for their potential to inhibit V. harveyi quorum sensing. Materials & methods: A library of halogenated furanones was prepared and derivatized using standard Pd-mediated coupling reactions and subsequently evaluated for their effects on V. harveyi bioluminescence. Results & conclusion: Several furanones inhibited QS-regulated bioluminescence, with gem-dichlorofuranone and tribromofuranone compounds proving especially effective. Importantly, a number of compounds were effective inhibitors of V. harveyi bioluminescence but did not have an impact on bacterial growth.

Key molecular alterations found in the diagnosis and prognosis of brain tumours have been revealed by the latest advances in transcriptomic and genome-wide analysis. In-depth studies revealed that alterations of the V-Raf murine sarcoma viral oncogene homolog B (BRAF) could be shared by different brain tumour types. The identification of BRAF p.V600E mutations in gliomas is nowadays of more importance regarding the development of BRAF-targeted inhibitors. This report presents the case of a 37-year-old female with a voluminous expansive neoplastic lesion, extending from the lenticulocapsular region to the medial aspect of the temporal lobe on the left. Pathological examination revealed an astrocytic neoplasm without high-grade histological features in small biopsy fragments. The molecular study revealed the presence of a mutation in the BRAF V600E gene and CDKN2A/2B homozygous deletion. The lesion was partially removed and irradiated. The patient has been on treatment with dabrafenib plus trametinib for 10 months. In addition to reasonable tolerance, she obtained an impressive tumour reduction, which was manifested in the complete resolution of neurological deficits and in the full acquisition of autonomy. The remarkable results reported in this clinical case justify the pressing need to identify new therapeutic targets in gliomas in the current era of precision medicine.

AIM: Our aim was to progress in bringing molecular medicine to routine clinical practice in the setting of paediatric neuro-oncology. We have implemented a protocol between Ipatimup and Centro Hospitalar Universitário de São João for the rapid and efficient delivery of the molecular portrait of paediatric brain tumours. MATERIAL AND METHODS: We have enrolled 92 patients with the following inclusion criteria: Age 0-18 years; newly diagnosed brain tumour; previously diagnosed brain tumour, whenever it presented as rare, aggressive or refractory disease; availability of tumour material; signed informed consent. Tumour samples were centrally reviewed by expert pathologists and profiled using the Oncomine Childhood Cancer Research Assay. RESULTS: In the 92 tumours that were molecularly profiled, BRAF was the most frequently altered gene, especially in pilocytic astrocytomas, being also detected in other LGG and HGG. Other commonly mutated genes were PIK3CA and FGFR, the former in HGG and the latter in LGG. MYB and RAF1 rearrangements were also found in low grade glial/glioneuronal tumours, while HGG showed a more complex profile, with many cases harbouring multiple alterations in EGFR, PDGFRA, ATRX, H3F3A, HIST1H3B, TP53, among others. A 16-year old patient with CMMR (homozygous mutation in PMS2) developed a glioblastoma that carried nearly 5x the average number of mutations. Among the 8 medulloblastomas, 2 showed mutations in the SHH pathway (1 in PTCH1 and one in SUFU) and 2 in the WNT pathway (1 in CTNNB1 and one in APC). In the remaining cases, one ependymoma presented MYCN amplification, while no alterations were detected in 3 patients. CONCLUSIONS: This study enabled the detailed molecular study of 92 paediatric brain patients, allowing a more robust tumour classification and the identification of actionable alterations. A subset of the patients are already undergoing targeted therapy, mainly using BRAF or MEK inhibitors with generally good improvement.

Tritium-labelled phencyclidine (PCP) hydrochloride (12 mg/kg) was injected SC for six consecutive days into two groups of eight male rats maintained at 85% of their initial free-feeding weights. Eight days after the last injection, electric footshock raised fat levels of PCP 28% over nonshocked controls, and lowered blood levels 18%, but did not alter brain levels of the drug significantly. Thus, application of an acute stressor does result in redistribution of tissue stores of phencyclidine as predicted in the literature; however, the direction of the redistributions was to fat, rather than to brain. To explore the relation of a long-term stressor (one that eliminates adipose tissue as a sink for mobilized PCP), exploratory behavior was evaluated in male rats during six days of food deprivation commencing after six daily injections of PCP HCl (2 or 4 mg/kg, SC). Exploratory behavior of the 4 mg/kg dose group was abruptly altered, compared to saline controls, at six days of food deprivation, when the rats' body weights were about 70% of initial weights and when body fat would be severely reduced or depleted. To assess replicability and generalizability of this phenomenon, PCP HCl (4 or 8 mg/kg, SC) or dextroamphetamine sulfate (3.2 or 6.4 mg/kg, SC) was injected into male rats for six days and food deprivation followed afterward for nine consecutive days, or until similar body weight reductions as in the first experiment were achieved. Again, exploratory behavior was altered in comparison to saline controls in phencyclidine-treated rats (at the 4 mg/kg dose level) when rats reached about 70% of initial weights. Behavior of dextroamphetamine-treated animals (at 3.2 mg/kg) was also different from controls, suggesting that interactions between food deprivation (stress) and lipophilic drugs of abuse occur when body fat stores reach a threshold.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Resistance to treatment is a major clinical problem and a major cause of cancer-related deaths. Understanding the biological basis of resistance acquisition is of utmost importance to improve the clinical management of cancer patients. NGS analysis of human lung cancer (LC) tumors from patients that relapsed after treatment with EGFR-tyrosine kinase inhibitors (TKI), revealed that the p.T790M resistance mutation is not present in all the relapsing tumor cells, suggesting that LC cells can become resistant even if not carrying the p.T790M mutation. Using in vitro treatments with conditioned medium (CM) and in vivo co-inoculation experiments, we show that LC cells sensitive to EGFR-TKIs (S cells) acquire resistance faster when treated with CM from LC cells resistant to EGFR-TKIs (R cells) or when co-inoculated with R cells in opposite flanks of the same animal. Importantly, we show that acquisition of resistance is not due to the emergence of subpopulations of cancer cells with new resistance mutations. Using transcriptomics, we show that acquisition of resistance is associated with upregulation of genes involved in endocytosis, namely caveolins CAV1 and CAV2. These findings were validated in human clinical samples, where an increase in CAV1 and CAV2 expression was associated with tumor relapse after treatment with EGFR-TKIs. Our results suggest that acquisition of resistance to targeted therapies results from the combined effect of selection of cells harboring specific resistance mutations and horizontal transfer of the resistance phenotype. These findings may pave the way to bring intercellular communication into the realm of cancer treatment. One Sentence Summary Resistance to EGFR inhibitors is transferred horizontally between lung cancer cells and is associated with gain of expression of caveolins.

Medulloblastoma is the most frequent pediatric malignant brain tumor, and is divided into four main subgroups: WNT, SHH, group 3, and group 4. MYCN amplification is an important medulloblastoma prognostic biomarker. We aimed to molecular classify and predict MYCN amplification in a single assay. It was included 209 medulloblastomas from 205 patients (Brazil, Argentina, and Portugal), divided into training (n = 50) and validation (n = 159) sets. A nCounter assay was carried out using a custom panel for molecular classification, with additional genes, including MYCN. nSolver 4.0 software and the R environment were used for profiling and MYCN mRNA analysis. MYCN amplification by FISH was performed in 64 cases. The 205 medulloblastomas were classified in SHH (44.9%), WNT (15.6%), group 3 (18.1%) and group 4 (21.4%). In the training set, MYCN amplification was detected in three SHH medulloblastomas by FISH, which showed significantly higher MYCN mRNA counts than non-FISH amplified cases, and a cutoff for MYCN amplification was established ( $$\overline{X }$$ + 4σ = 11,124.3). Applying this threshold value in the validation set, we identified MYCN mRNA counts above the cutoff in three cases, which were FISH validated. We successfully stratified medulloblastoma molecular subgroups and predicted MYCN amplification using a single nCounter assay without the requirement of additional biological tissue, costs, or bench time.

Mastocytosis is a heterogeneous group of disorders characterized by expansion and accumulation of clonal mast cells. Patients mainly present with either cutaneous lesions, anaphylaxis, or both. Its low prevalence and unusual features often hinder its diagnosis for several years. We report the case of an 18-year-old male who was referred to our department with a long-standing history of atypical skin lesions, allergic rhinitis, exercise-induced bronchoconstriction and what was believed to be food-related flushing and anaphylaxis, that was later diagnosed with mastocytosis. This case illustrates the need to consider investigating for mastocytosis when recurrent anaphylaxis is present, especially in the presence of atypical skin lesions, even if normal serum basal tryptase levels and allergic sensitization are present.

Central nervous system tumors comprise 26% of cancer in children, representing the most frequent solid neoplasms. Embryonal tumors comprise 15% of them, and they are defined as "small round blue cells" in which morphology is reminiscent of the developing embryonic nervous system. They are the most common high-grade central nervous system neoplasms. Over the years, molecular research has been improving our knowledge concerning these neoplasms, stressing the need for tumor reclassification. Indeed, the revised 2016 fourth edition of the World Health Organization classification introduced genetic parameters in the classification. Specific molecular signatures allow a more accurate risk assessment, leading to proper therapeutic approach and potentially improved prognosis. Holding this new approach, medulloblastoma is noteworthy. The present classification combines the previous histologic classification with a new genetic definition in WNT-activated, sonic hedgehog-activated and non-WNT/non-sonic hedgehog. Molecular data are also a defining feature in the diagnosis of atypical teratoid/rhabdoid tumors and embryonal tumors with multilayered rosettes. However, there are still embryonal tumors that challenge the present World Health Organization classification, and new molecular data have been underlining the need for novel tumor entities. Likewise, recent research has been highlighting heterogeneity in recognized entities. How to translate these molecular developments into routine clinical practice is still a major challenge.