Aim: To comparatively analyse and interpret the molecular profiles of sporadic odontogenic keratocysts (OKC) with bilateral non-syndromic odontogenic keratocysts employing next-generation sequencing (NGS). Materials and Methods: All histopathologically confirmed cases were processed for 50 hotspot gene panel using NGS, followed by protein-protein analysis using the STRING Consortium 2023. Results: Except for 1 case, which was seen in the maxilla in a female patient, all included cases affected the mandible in males. In sporadic cases, a missense mutation was frequently found with either gain/ loss of function (GOF/LOF). TP53 showed a missense mutation with LOF at exon 5 and a nonsense mutation with LOF at exon 10. Other mutations were noted in the MET gene exon 19 and BRAF gene exon 11. Contrariwise, an identical mutation was seen in the left and right lesions of bilateral OKC, which was a mutation of TP53 with LOF at exon 8. Additionally OKC of the right side showed a gain-of-function (missense mutation) of the NRAS gene at exon 3. Conclusion: The TP53 gene mutation plays a significant role in the pathogenesis of OKC and supports its neoplastic nature. Bilateral OKC showed additional NRAS mutation, and sporadic cases demonstrated MET and BRAF mutations.

Liver involvement by histiocytic and dendritic cell neoplasms signals high-risk disease, often necessitating closer monitoring and aggressive management. Severe cases may progress to liver failure, requiring transplantation. Liver involvement occurs in about one-third of patients with systemic juvenile xanthogranuloma (JXG) and 20% to 60% of pediatric patients with Langerhans cell histiocytosis (LCH), particularly in multiorgan disease. Tyrosine kinase inhibitors show promise in LCH treatment, but optimal timing for treatment cessation remains uncertain. We present 2 pediatric cases, 1 with LCH, and the other with disseminated JXG, along with a literature review emphasizing liver histopathology and transplant considerations. These cases highlight distinct histological patterns. In LCH, progressive bile duct destruction led to ductopenic cholestatic cirrhosis and secondary sclerosing cholangitis. In contrast, in the case of JXG, bile ducts remained intact despite being surrounded by histiocytes. In both, disease localization to larger, segmental portal tracts may reduce liver biopsy sensitivity. In LCH, BRAF inhibitor therapy triggered a granulomatous reaction that could mimic disease recurrence in the liver graft. Other histiocytoses typically spare the bile ducts and do not cause biliary cirrhosis. Recognizing these distinct infiltration patterns can aid diagnosis and management.

Background:Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. For stratification purposes, rhabdomyosarcoma is classified into fusion-positive RMS (alveolar rhabdomyosarcoma) and fusion-negative RMS (embryonal or spindle cell/sclerosing, FN-RMS) subtypes according to its PAX::FOXO1 fusion status. This study aims to highlight the pathologic and molecular characteristics of a cohort of FN-RMS using a targeted NGS RNA-Seq assay.Methods:Twelve tumors were analyzed through targeted RNA-Seq using the Trusight Pancancer panel from Illumina. Molecular alterations were then correlated with the clinicopathological features.Results:Of the 12 tumors analyzed, we identified 6 embryonal rhabdomyosarcomas (ERMSs) harboring mutations in key signaling molecules (KRAS, HRAS, NRAS, and FGFR4), oncogenic DICER1 mutations in 2 ERMS, pathogenic TP53 and NF1 mutations in an ERMS with features of anaplasia, a TEAD1::NCOA2 gene fusion in a congenital spindle cell and sclerosing rhabdomyosarcoma (SSRMS), and a FUS::TFCP2 gene fusion in a skull base SSRMS. Only 1 ERMS in the bladder showed no reportable molecular alterations.Conclusion:We illustrate case examples demonstrating how a combined morphological and molecular approach with targeted RNA-Seq can aid in diagnosis and identify clinically actionable alterations in pediatric FN-RMS.

We present a unique case of a 33-year-old gravida that was referred to our hospital with an umbilical vessel aneurysm presenting as a large placental cyst on ultrasound. Although the 20-week anomaly scan showed no structural abnormalities, routine fetal biometry scanning at 30 weeks of gestation revealed an abnormal placental cystic structure, located subchorionic under the umbilical cord insertion. Given the uncertainty of the origin of the structure’s origin and its unpredictable evolution with possible adverse effect on the fetus, a cesarean section was performed delivering a healthy baby. Histopathological examination of the placenta showed an aneurysmal vein with thinning of the vessel wall and fragmented smooth muscle. Umbilical cord aneurysm represents an exceptionally rare placental anomaly, with umbilical vein aneurysms being associated with variable fetal mortality rates, ranging from those observed in uncomplicated pregnancies to 82% in documented cases. Therefore, a multidisciplinary approach is essential to optimize fetal outcomes.

Glutaredoxin 5 (GLRX5) is a mitochondrial protein encoded by the GLRX5 gene, which is essential for cellular redox homoeostasis, lipoic acid synthesis, and iron-sulfur cluster transfer. Rare cases of pathogenic GLRX5 mutations have been associated with sideroblastic anemia and non-ketotic hyperglycinemia with progressive spasticity and cavitating leukoencephalopathy. We report an 11-month-old child, who died following aspiration, with severe cardiomyocyte mitochondrial abnormalities and cerebral white matter degeneration in the context of a homozygous GLRX5 variant (c.208A>G, p.S70G).

Background:In a non-forensic hospital setting, neonatal death within the first week of life is often related to premature birth and/or lung diseases. Without post-mortem examination, the identification of the cause of death may be challenging. Autopsy can confirm the clinical diagnosis, uncover additional information or change the diagnosis. Our study aimed to assess the correlation between the clinical diagnosis and post-mortem findings in early neonatal deaths.Methods:The retrospective study included autopsy cases with neonatal deaths within the first 7 days of life (arbitrary time interval 2006-2021). Discrepancies between clinical and histopathological findings were classified into 3 groups: (i) full agreement, (ii) additional findings discovered by autopsy, or (iii) autopsy changed the diagnosis.Results:A cohort of 27 cases could be identified and lung pathologies were the most common finding (56%). Additional findings could be discovered in 48% of cases. Major discrepancies which changed the clinical diagnosis could be found in 11% (n = 3/27) of cases.Conclusion:Frequently, post-mortem examinations validate the clinical diagnosis while revealing crucial information in a few cases. In these discrepant cases, autopsy findings can provide information for genetic counselling and quality control of clinical management.

Maude Abbott was a pioneering female Canadian physician who became a world authority on medical museums and congenital heart disease. Abbott spent almost all her career in highly sexist, discriminatory work environments. This paper reviews Abbott’s life and accomplishments, but, more importantly, analyzes her pathway to success in the masculine world of early 20th-century academic pathology. Abbott, though well-trained as a pathologist, never provided clinical service, but instead worked as museum curator at McGill University. She established the International Association of Medical Museums (predecessor to the International Academy of Pathology), edited its journal, and essentially ran the organization. Abbott, surrounded by influential males, dealt differently with each. In general, she recognized that male doctors believed women lacked the gravitas to lead major initiatives but that she could circumnavigate this supposed impediment by co-leading projects with male counterparts, preferably ones too busy to get in her way. She repeatedly used this approach, and by doing most of the work but sharing credit, succeeded in gaining reputation, accomplishment, and advancement. Abbott’s pioneering work on congenital heart disease established her as one of the founders of pediatric pathology, and, overall, her career promoted the entry of women physicians into the pathology profession.