Ana Costa Braga

Peroxidasin (PXDN) is an enzyme of the peroxidase family that plays a critical role in extracellular matrix (ECM) formation and tissue development. In the kidney, very few studies using animal cells suggested that PXDN may play a role in the maintenance of the structural and functional integrity of the renal ECM. However, the normal expression and (patho)physiological roles of PDXN in mature and developing human kidney remains unknown.,In this work we used fluorescent immunohistochemistry and advanced microscopy and image processing methodologies to perform a quantitative characterization of PXDN expression in the different anatomic compartments of histologically normal kidney tissue, obtained from adult nephrectomy specimens, and from postmortem fetal and neonatal kidney specimens (excluding death by kidney disease and genitourinary developmental anomalies).,Results show that PXDN is expressed in all mature kidney compartments, but at significantly higher levels in tubular epithelial cells, particularly in the distal tubules. A similar PXDN expression pattern was observed in the developing kidney, as early as the in the comma-shaped-body stage. In the fetal kidney, PXDN was diffusely expressed in the branches of the ureteric bud but not in the cells of the metanephric blastema.,This is the first demonstration that PXDN is differentially expressed in histologically normal human renal parenchyma, exhibiting a remarkably consistent pattern of predominant tubular expression since the early stages of metanephrogenesis This data suggests a relevant, compartment-specific, role of PXDN in nephrogenesis and in the kidney physiology, highlighting a main role in tubular functions, that is worth further investigation.

Introduction: Orofacial clefts are common congenital malformations that may occur in isolation or as part of a syndrome. Early prenatal diagnosis provides crucial information for parental counseling, delivery planning, and multidisciplinary neonatal care. This study aimed to review orofacial cleft cases diagnosed during the prenatal period and to assess the relationship between cleft type, associated anomalies, genetic findings and pregnancy outcomes.Methods: This retrospective study included all fetuses with a prenatal diagnosis of cleft lip and/or cleft palate who received obstetric care at the Unidade Local de Saúde São João between January 2014 and December 2023. Data collected included baseline maternal characteristics, fetal sex, gestational age at diagnosis, associated anomalies, genetic and pathological evaluation and pregnancy outcomes. Results: Forty-eight fetuses were included. Prenatal diagnosis was most often made in the second trimester (77.1%), while all first-trimester diagnoses were associated with additional anomalies. Overall, 20 fetuses (41.7%) had syndromic or non-isolated clefts, accounting for all chromosomal and genetic abnormalities. In isolated cases (58.3%), genetic testing consistently yielded normal results, with only two of them receiving a genetic diagnosis postnatally. Eighteen pregnancies were terminated, mostly in cases with associated anomalies.Conclusion: In this single-center retrospective case series, chromosomal and genetic abnormalities were only detected in fetuses with syndromic clefts or additional anomalies. Among isolated cases, genetic testing was uniformly normal. These results reinforce that prenatal genetic testing may be most valuable when syndromic features or a strong family history are present, rather than as a routine in isolated clefts. Further multicenter studies are needed to support this approach and define standardized protocols.

Recurrent pregnancy loss (RPL) is a multifactorial condition affecting 1–5% of couples, often with unclear etiology. Idiopathic pregnancy losses (iPLs) are particularly challenging due to unknown molecular mechanisms. This study investigates the transcriptomic profiles of first-trimester products of conception (POC) from iPLs to uncover underlying molecular pathways. We performed RNA-sequencing on nine POC samples, identifying two distinct clusters enriched in trophoblast and decidual cells. Deconvolution analysis revealed reduced syncytiotrophoblast (STB) cells, with increased cytotrophoblast (CTB) and extravillous trophoblast (EVT) cells in iPLs. Gene Set Enrichment Analysis highlighted immune pathways enrichment in both villous trophoblasts and decidua. Gene ontology (GO) analysis of downregulated genes implicated hormonal and endocrine processes, consistent with STB reduction, while upregulated genes were associated with MHC protein complex and immune system processes, aligning with EVT increases. Histological analysis showed chronic histiocytic intervillositis (CHI) in iPL samples, supporting maternal immune dysregulation in unexplained RPL. Together, transcriptomic and histological analyses indicate that immune signaling dysregulation and impaired trophoblast differentiation may underlie unexplained iPLs. These findings bridge molecular and histopathological evidence, underscoring the interplay between trophoblast dysfunction and immune imbalance. Our results provide insights into iPL pathogenesis, highlighting potential biomarkers that may contribute to improved diagnosis and future research.

Syphilis is a preventable and treatable disease, which continues to strike low-income countries and vulnerable populations in high-income countries. It is caused by T pallidum , a spirochete capable of traversing the placental barrier, with a high rate of fetal and placental infection. Congenital syphilis (CoS) has poor prognosis if left untreated. Autopsy and placental evaluation are important tools to diagnose this disease in the obstetric scenario, to reveal the correct cause of demise and prevent complications in future pregnancies. We describe the histologic findings of eleven feto-placental examinations of non-treated CoS with fetal hydrops and stillbirth. Fetal findings are variable, with hydrops, X-ray long bone metaphyseal bands and hepatic lesions as the most consistent autopsy findings. The combination of chronic and acute villitis/intervillitis is a common placental feature in CoS, and the presence of mixed inflammatory populations is a key to suspect treponemal infection. Mothers from vulnerable populations and with poor obstetric care also deserve increased efforts to rule out CoS as cause of death. This constellation of findings must lead to further testing with direct methods (PCR or tissue immunohistochemistry for T pallidum ).

Xanthogranulomatous inflammation is characterized by the presence of foamy histiocytes associated with other inflammatory cells like lymphocytes, plasma cells and neutrophils. It is a rare inflammatory process, which has been more frequently described in chronic pyelonephritis and cholecystitis. Xanthogranulomatosis usually triggers a large distortion of the affected organ, which is secondary to the severe inflammatory response that characterizes this type of lesion. Only a few cases of xanthogranulomatous salpingo-oophoritis have been published to date. Here, we report the case of a xanthogranulomatous salpingo-oophoritis in a patient with endometriosis, suffering from chronic pelvic pain and long-standing infertility. The association between endometriosis and xanthogranulomatous inflammation is extremely rare and can possibly represent a severe histologic expression of this common disorder.

Uterine perivascular epithelioid cell tumors (PEComas) are rare neoplasms that may show overlapping morphology and immunohistochemistry with uterine smooth muscle tumors. In this study, we evaluated the morphologic, immunohistochemical, and molecular features of 32 PEComas, including 11 with aggressive behavior. Two distinct morphologies were observed: classic (n=30) and those with a lymphangioleiomyomatosis appearance (n=2). In the former, patients ranged from 32 to 77 (mean: 51) years and 13% had tuberous sclerosis. Tumors ranged from 0.2 to 17 (mean: 5.5) cm with 77% arising in the corpus. Epithelioid cells were present in 100% and a spindled component was seen in 37%. Nuclear atypia was low (53%), intermediate (17%), or high (30%). Mitoses ranged from 0 to 36 (mean: 6) and 0 to 133 (mean: 19) per 10 and 50 high-power fields, with atypical mitoses present in 30%. Thin and delicate vessels were noted in 100%, clear/eosinophilic and granular cytoplasm in 93%, stromal hyalinization in 73%, necrosis in 30%, and lymphovascular invasion in 10%. All tumors were positive for HMB-45, cathepsin K, and at least one muscle marker, with most expressing melan-A (77%) and/or MiTF (79%). A PSF-TFE3 fusion was identified in one while another showed a RAD51B-OPHN1 fusion. Follow-up ranged from 2 to 175 (mean: 41) months, with 63% of patients alive and well, 20% dead of disease, 13% alive with disease, and 3% dead from other causes. In the latter group (n=2), patients were 39 and 49 years old, one had tuberous sclerosis, while the other had pulmonary lymphangioleiomyomatosis. Both tumors expressed HMB-45, cathepsin K, and muscle markers, but lacked TFE3 and RAD51B rearrangements. The 2 patients are currently alive and well. Application of gynecologic-specific criteria (≥4 features required for malignancy: size ≥5 cm, high-grade atypia, mitoses >1/50 high-power fields, necrosis, and lymphovascular invasion) for predicting outcome misclassified 36% (4/11) of aggressive tumors; thus, a modified algorithm with a threshold of 3 of these features is recommended to classify a PEComa as malignant.

Aim: To evaluate the intraobserver and interobserver reproducibility of the HER2 in‐situ hybridization (ISH) test in breast cancer by measuring the impact of counting different numbers of invasive cancer cells.Methods and results: A cohort of 101 primary invasive breast cancer cases were evaluated for HER2 gene amplification by silver ISH, and the concordance among four observers with different levels of experience, counting different numbers of invasive cancer cells, was determined. The evaluation of the samples included scoring 20 nuclei, in three different areas. The cases were scored twice, with a washout interval of at least 2 weeks. We observed an increase in the intraobserver concordance rate between the first and second evaluations with an increase in cell count. A count of 60 invasive cells was needed to obtain a concordance rate near 95% and an agreement rate greater than 0.80 by all observers. The interobserver concordance rate of the HER2 test also increased with the increase in cell count, reaching at least a 90% concordance rate with a count of 60 invasive cells. The median variability of both the HER2/CEP17 ratio and the average HER2 copy number between different evaluations decreased with the increase in cell count, being statistically higher in HER2‐positive cases.Conclusions: The minimal cell number recommended in current guidelines should be raised to at least 40, and preferably 60, invasive cells. Moreover, cases with amplification levels close to the threshold should be subjected to a dual count from an experienced observer.