Fluorescence confocal microscopy for evaluation of fresh surgical specimens and consecutive tumor cell isolation in rare pediatric tumors.

Fluorescence confocal microscopy (FCM) is an optical technique that uses laser light sources of different wavelengths to generate real-time images of fresh, unfixed tissue specimens. FCM allows histological evaluation of fresh tissue samples without the associated cryo artifacts after frozen sectioning. The aim of this study was to prospectively evaluate pediatric tumor specimens and assess their suitability for fresh tumor sampling. In addition, we aimed to determine whether tumor cell isolation for stable cell culture is still feasible after FCM imaging. Pediatric tumor specimens were imaged using FCM. Tumor viability and suitability for tissue sampling were evaluated and compared with H&E staining after paraffin embedding. In addition, FCM-processed and non-FCM-processed tissue samples were sent for tumor cell isolation to evaluate possible effects after FCM processing. When comparing estimated tumor cell viability using FCM and H&E, we found good to excellent correlating estimates (intraclass correlation coefficient = 0.891, p < 0.001), as well as substantial agreement in whether the tissue appeared adequate for fresh tissue collection (κ = 0.762, p < 0.001). After FCM, seven out of eight samples yielded passable cell cultures, compared to eight out of eight for non-FCM processed samples. Our study suggests that the use of FCM in tumor sampling can increase the yield of suitable fresh tumor samples by identifying viable tumor areas and ensuring that sufficient tissue remains for diagnosis. Our study also provides first evidence that the isolation and growth of tumor cells in culture are not compromised by the FCM technique.

Survey Data and Experience from a Pediatric Pathology Workshop in Indonesia: Understanding Practice Needs and Utility of Outreach Teachings.

Objective: We aimed to share the post-workshop survey results of a pediatric pathology course held in Jakarta, Indonesia. Methods: Questionnaires were distributed to participants; responses from practicing pathologists and pathologists-in-training were analyzed. Results: The respondents (107 pathologists of 143 attendees) were predominantly female (83.2%) and 31-60 years of age (77.5%). Over half (71.7%) signed out pediatric and perinatal specimens but only a third (34.3%) were comfortable handling such cases. Most (70.0%) felt that their exposure to pediatric and perinatal cases during their training was inadequate. All respondents thought that the workshop was helpful, and would highly recommend it to their colleagues. Post-workshop, the respondents claimed expansion of differential diagnoses (49.5%) and better understanding of what to include in pathology reports (41.1%). Conclusions: Our experience affirms the need for subspecialty courses to address training gaps in developing countries. Post-workshop surveys are helpful in determining actionable deficiencies and effectiveness of outreach teachings.

Molecular Alterations in Pediatric Solid Tumors.

Pediatric tumors can be divided into hematologic malignancies, central nervous system tumors, and extracranial solid tumors of bone, soft tissue, or other organ systems. Molecular alterations that impact diagnosis, prognosis, treatment, and familial cancer risk have been described in many pediatric solid tumors. In addition to providing a concise summary of clinically relevant molecular alterations in extracranial pediatric solid tumors, this review discusses conventional and next-generation sequencing-based molecular techniques, relevant tumor predisposition syndromes, and the increasing integration of molecular data into the practice of diagnostic pathology for children with solid tumors.

The clinical and pathological features of Kimura disease in pediatric patients.

Background: Kimura disease is characterized by inflammation, with its underlying causes remaining uncertain. There is a lack of comprehensive and systematic research on the pathology of this condition in pediatric patients. Our objective is to study the clinical and pathological attributes of Kimura disease in pediatric patients and investigate the potential diagnostic significance of immunoglobulin E (IgE) in this context. Methods: Clinical and laboratory information, pathological characteristics, and follow-up data were correlated to examine the distinctive features. Immunohistochemistry, acid-fast staining, and molecular assay were used to identify the presence of IgE and pathogens. Results: We conducted an analysis of five cases of Kimura disease in pediatric patients at our hospital. The patients' ages ranged from 5 years and 7 months to 14 years and 2 months, with 4 (80%) being male. The most common site was the head and neck region, particularly the postauricular subcutaneous area. Eosinophilia was observed in four patients (80%), and two patients (40%) had elevated serum immunoglobulin E (IgE) levels. Histopathological changes included eosinophilic infiltrates, follicular hyperplasia, and the proliferation of postcapillary venules. Immunohistochemical results supported the reactive nature of the lymphoid process and IgE deposition in the follicle, while no specific pathogens were discovered by special staining. All patients underwent surgical excision, and none experienced recurrence in their original location. Conclusion: Children with Kimura disease show distinct eosinophilic and IgE alterations in both laboratory findings and pathological features. The application of immunohistochemical staining of IgE could serve as a promising marker for diagnosing Kimura disease.

Developing Odontoma in the Mandible of an Eight-Year-Old Boy.

Benign mixed odontogenic tumors have been repeatedly classified and reclassified over the past few decades. Odontoma is considered a hamartoma due to its slow growth and non-aggressive nature. We present an interesting case of developing odontoma in an eight-year-old boy. His complaint was a slow-growing swelling in the lower right back tooth region. Clinical examination revealed a carious deciduous second molar. The orthopantomogram revealed a well-defined radiolucency around the unerupted mandibular first premolar and impacted mandibular second premolar. Histopathology revealed an odontogenic epithelial lining overlying myxofibrous stroma with inflammatory cells and calcified structures with few odontogenic rests. Special staining methods including Van Gieson and modified Gallego stains led to the final diagnosis of a developing odontoma.

Dick van Velzen and the Burnside warehouse organ scandal in Nova Scotia, Canada.

Dick van Velzen practiced as a pediatric pathologist at Alder Hey Children's Hospital in Liverpool, England from September 1988 until December 1995; he then relocated to the IWK-Grace Health Centre, a children's and maternity hospital in Halifax, Nova Scotia, Canada, where he practiced until he was fired for cause in January 1998. About a year and a half later, his practice in Liverpool came under increasing scrutiny, with the initial focus on the massive collection of post-mortem pediatric organs he had accumulated for planned future research on sudden infant death syndrome. Soon, a Parliamentary Inquiry began investigating the full scope of his Liverpool practice. During the Inquiry, another organ-hoarding scandal erupted; van Velzen, when leaving Halifax after his dismissal, had put his family's personal belongings into a storage facility at Burnside Industrial Park and then did not pay bills. As his belongings were being prepared for auction, formalin-fixed organs were found, and a Canada-wide arrest warrant for disrespect for human remains was issued by the Halifax Police. While the Alder Hey scandal resulted in a 535-page-long Parliamentary Report and the Human Tissue Act, van Velzen was never charged criminally in the UK. The largely unknown story of his second organ scandal in Halifax, is related here. Although he had obtained the body parts with the consent of the parents of the child to which they had belonged, his failure to properly identify and store them traumatized parents already impacted by his organ-hoarding in the UK, traumatized additional parents in Halifax, and resulted in significant waste of public resources in investigating the case. He pled guilty to "indignity to a human body" in Canada and was fined and placed on 12 months' probation.

Adenoid Cystic Carcinoma of the Oral Cavity- A Case Report Comparing the Differences and Similarities Between a Child and an Adult Patient.

Adenoid cystic carcinoma is a malignant neoplasm primarily of the salivary gland, which can also involve lacrimal glands and other exocrine glands. Adenoid cystic carcinoma rarely presents in the buccal mucosa and young children, and among the major salivary glands, it rarely occurs in the sublingual gland. We are presenting two cases of Grade 1- adenoid cystic carcinoma. One in the buccal mucosa of an eight-year-old boy and another in the sublingual gland of a 50-year-old female patient. The site and age of occurrence can make a huge difference in diagnosis and treatment planning due to the unpredictability of the lesion. Proper diagnosis, treatment planning, and appropriate treatment help improve the lesion's prognosis. Even though such lesions rarely occur, awareness among the Oral and maxillofacial fraternity is very important in providing proper patient care.

The Placenta in Congenital Langerhans Cell Histiocytosis: A Case Report of Unusual Involvement of Chorionic Plate and Umbilical Vein.

The congenital presentation of Langerhans cell histiocytosis (LCH) is a rare presentation of an uncommon neoplastic process. Concurrent placental parenchymal involvement is even more rare, with just 2 cases of congenital multisystem LCH with placental involvement reported in English medical literature thus far. Here, we present a case of a liveborn male born at 37-weeks, 6-day gestation with congenital LCH focally involving the placenta. Langerhans cells were identified in an area of the placenta showing an unusual mononuclear cell infiltrate in the wall of the umbilical vein. Langerhans cells were also focally identified in areas of chronic villitis, as well as normal-appearing chorionic plate. The examination of the placenta in cases of clinical suspicion of LCH can be of paramount importance since it may provide the early diagnostic evidence of LCH. In this context, placental involvement by LCH should be considered even in the absence of abnormal histology.

Automated Deep Learning-Based Classification of Wilms Tumor Histopathology.

(1) Background: Histopathological assessment of Wilms tumors (WT) is crucial for risk group classification to guide postoperative stratification in chemotherapy pre-treated WT cases. However, due to the heterogeneous nature of the tumor, significant interobserver variation between pathologists in WT diagnosis has been observed, potentially leading to misclassification and suboptimal treatment. We investigated whether artificial intelligence (AI) can contribute to accurate and reproducible histopathological assessment of WT through recognition of individual histopathological tumor components. (2) Methods: We assessed the performance of a deep learning-based AI system in quantifying WT components in hematoxylin and eosin-stained slides by calculating the Sørensen-Dice coefficient for fifteen predefined renal tissue components, including six tumor-related components. We trained the AI system using multiclass annotations from 72 whole-slide images of patients diagnosed with WT. (3) Results: The overall Dice coefficient for all fifteen tissue components was 0.85 and for the six tumor-related components was 0.79. Tumor segmentation worked best to reliably identify necrosis (Dice coefficient 0.98) and blastema (Dice coefficient 0.82). (4) Conclusions: Accurate histopathological classification of WT may be feasible using a digital pathology-based AI system in a national cohort of WT patients.

Current Utilization of Electron Microscopy in the Pediatric Pathology Setting: A Survey by the SPP Practice Committee.

BACKGROUND: Electron microscopy (EM), once an important component in diagnosing pediatric diseases, has experienced a decline in its use. To assess the impact of this, pediatric pathology practices were surveyed regarding EM services. METHODS: The Society of Pediatric Pathology Practice Committee surveyed 113 society members from 74 hospitals. Settings included 36 academic tertiary, 32 free-standing children's, and 6 community hospitals. RESULTS: Over 60% maintained in-house EM services and had more than 2 pathologists interpreting EM while reporting a shortage of EM technologists. Freestanding children's hospitals had the most specimens (100-200 per year) and more diverse specimen types. Hospitals with fewer than 50 yearly specimens often used reference laboratories. Seventeen had terminated all in-house EM services. Challenges included decreasing caseloads due to alternative diagnostic methods, high operating costs, and shortages of EM technologists and EM-proficient pathologists. Kidney, liver, cilia, heart, and muscle biopsies most often required EM. Lung/bronchoalveolar lavage, tumor, skin, gastrointestinal, nerve, platelet, and autopsy samples less commonly needed EM. CONCLUSIONS: The survey revealed challenges in maintaining EM services but demonstrated its sustained value in pediatric pathology. Pediatric pathologists may need to address the centralization of services and training to preserve EM diagnostic proficiency among pathologists who perform ultrastructural interpretations.

Pulmonary Histopathologic Findings in Pediatric Patients After Hematopoietic Stem Cell Transplantation: An Autopsy Study.

BACKGROUND: Pathologic characterization of pulmonary complications following hematopoietic stem cell transplantation (HSCT) is limited. We describe lung findings in pediatric patients who died following HSCT and attempt to identify potential clinical associations. METHODS: Pathology databases at Texas Children's Hospital and the Children's Hospital of Philadelphia were queried (2013-2018 CHOP and 2017-2018 TCH). Electronic medical records and slides were reviewed. RESULTS: Among 29 patients, 19 received HSCT for hematologic malignancy, 8 for non-malignant hematologic disorders, and 2 for metastatic solid tumors. Twenty-five patients (86%) showed 1 or more patterns of acute and organizing lung injury. Sixty-two percent had microvascular sclerosis, with venous involvement noted in most cases and not correlating with clinical history of pulmonary hypertension, clinical transplant-associated thrombotic microangiopathy, irradiation, or graft-versus-host disease. Features suggestive of graft-versus-host-disease were uncommon: 6 patients had lymphocytic bronchiolitis, and only 2 patients had evidence of bronchiolitis obliterans (both clinically unexpected), both with a mismatched unrelated donor transplant. CONCLUSIONS: Acute and subacute alveolar injury (diffuse alveolar damage or organizing pneumonia) is common in pediatric patients who died following HSCT and is difficult to assign to a specific etiology. Microvascular sclerosis was frequent and did not correlate with a single distinct clinical feature.

A rare case of pediatric gastrointestinal mucormycosis with a review of the literature.

This manuscript discusses a rare case of pediatric gastrointestinal mucormycosis in a hospitalized patient who presented in diabetic ketoacidosis. A review of the literature is summarized to provide an overview of mucormycosis with a discussion of the mechanisms underlying the susceptibility of diabetic patients for this condition.

Comprehensive global collaboration in the care of 1182 pediatric oncology patients over 12 years: The Iraqi-Italian experience.

BACKGROUND: Iraq's health care system has gradually declined after several decades of wars, terrorism, and UN economic sanctions. The Oncology Unit at Children's Welfare Teaching Hospital (CWTH) in Baghdad was lacking basic facilities and support. To address this shortcoming, a humanitarian and educational partnership was established between CWTH and Sapienza University of Rome (SUR). METHODS: We investigated the outcomes of 80 online and 16 onsite educational sessions and 142 teleconsultation sessions from 2006 to 2014. We also determined the outcomes of pathology reviews by SUR of 1216 tissue specimens submitted by CWTH from 2007 until 2019 for second opinions. The primary outcomes were discordance, concordance, and changes among clinical diagnoses and pathology review findings. The measures included the frequency of teleconsultation and tele-education sessions, the topics discussed in these sessions, and the number of pathology samples requiring second opinions. FINDINGS: A total of 500 cases were discussed via teleconsultations during the study period. The median patient age was 7 years (range, 24 days to 16·4 years), and the cases comprised 79 benign tumors, 299 leukemias, 120 lymphomas, and 97 solid tumors. The teleconsultation sessions yielded 27 diagnostic changes, 123 confirmed diagnoses, and 13 equivocal impacts. The pathology reviews by SUR were concordant for 996 (81·9%) cases, discordant for 186 (15·3%), and inconclusive for 34 (2·8%). The major cause of discordance was inadequate immunohistochemical staining. The percentage of discordance markedly decreased over time (from 40% to 10%). The cause of the improvement is multifactorial: training of two CWTH pathologists at SUR, better immunohistochemical staining, and the ongoing clinical and pathologic telemedicine activities. The partnership yielded 12 publications, six posters, and three oral presentations by CWTH investigators. INTERPRETATION: The exchange of knowledge and expertise across continental boundaries meaningfully improved the diagnoses and management of pediatric cancer at CWTH.

Artificial Intelligence in Pediatric Pathology: The Extinction of a Medical Profession or the Key to a Bright Future?

Artificial Intelligence (AI) has become of increasing interest over the past decade. While digital image analysis (DIA) is already being used in radiology, it is still in its infancy in pathology. One of the reasons is that large-scale digitization of glass slides has only recently become available. With the advent of digital slide scanners, that digitize glass slides into whole slide images, many labs are now in a transition phase towards digital pathology. However, only few departments worldwide are currently fully digital. Digital pathology provides the ability to annotate large datasets and train computers to develop and validate robust algorithms, similar to radiology. In this opinionated overview, we will give a brief introduction into AI in pathology, discuss the potential positive and negative implications and speculate about the future role of AI in the field of pediatric pathology.

Intraoperative electromagnetic navigation bronchoscopy (IENB) to localize peripheral lung lesions: A new technique in the pediatric oncology population.

BACKGROUND: The utility, diagnostic yield and accuracy of lung biopsies in pediatric oncology patients are variable. Here we describe our preliminary results using intraoperative electromagnetic navigation bronchoscopy (IENB) for peripheral lung lesions to increase the surgical yield and accuracy in pediatric oncology patients. METHODS: From May 2018 until October 2020 all surgical lung biopsies on pediatric oncology patients were performed using IENB technology. IENB and tattooing with methylene blue dye, Indocyanine green dye or both followed by Video-assisted Thoracoscopic Surgery (VATS) was performed in the same setting. Data were collected retrospectively. Data points included diagnosis, technical success, pathologic diagnosis and alteration in treatment management and complications. RESULTS: A total of 10 biopsy procedures were performed on 8 patients during the study. The youngest patient was 7 years old. All had successful IENB with tattooing. All biopsies were diagnostic. No procedures were converted to open. There were no technical failures or procedure complications. One patient had a total of 11 biopsies, 6 from the right lung and 5 from the left, performed at 2 separate procedures. Another had 2 biopsies, one from the right lung and one from the left performed at the same operation. In 7 of the 8 patients treatment changes were made based on results of their biopsy. CONCLUSION: Here we present the first described experience of IENB and tattooing of peripheral lung lesions in the pediatric population. We have shown that IENB for peripheral lung lesion localization is a safe and effective technique in pediatric oncology.

Pediatric Hypersensitivity Pneumonitis: Clinicopathologic Characteristics of Two Cases with Fungal Triggers.

Background Hypersensitivity pneumonitis (HP) infrequently presents in childhood. Asthma or a pneumonia-like clinical presentation may lead to diagnostic delay, especially in children. Case Report: We present two cases of HP, a 6-year-old (Case 1) male and a 5-year-old (Case 2) female. Both cases had a negative infectious work-up and patchy ground glass lung opacities on chest computed tomography. Lung biopsies demonstrated lymphocytic bronchiolitis with granulomatous interstitial and peribronchial inflammation. Serology demonstrated elevated immunoglobulin precipitins toward Thermoactinomyces and Aspergillus species in Case 1 and Aspergillus fumigatus in Case 2. Both patients received steroid therapy and had symptom resolution. Conclusions: A diagnosis of HP should be considered in pediatric lung biopsies with granulomatous interstitial and peribronchial inflammation, if infectious etiologies are excluded. Integration of clinical, radiological, and laboratory findings can facilitate a timely diagnosis.

Unexpected death in a young child associated with anomalous aortic origin of the left main coronary artery without physical exertion: A case of an anomalous coronary artery with highly abundant elastic fibers.

Sudden death due to anomalous aortic origin of a coronary artery is far less common among young children in the absence of exercise stress. This report describes the case of a 2-year-old boy with a lower respiratory tract infection who suffered sudden cardiac arrest in his bed at home. The autopsy revealed that the left coronary artery (LCA) originated from the right sinus of Valsalva with an acute angle takeoff and traveled between the aorta and the pulmonary trunk (an interarterial course). Upon histological examination, the LCA, before reaching its major branches, was located adjacent to the outside of the aortic wall without an intramural passage, and the arterial wall was composed almost exclusively of elastic fibers without media containing smooth muscle cells throughout the entire length of the abnormal running. Screening tests for respiratory virus infection detected enterovirus in the lung tissue. In association with an acute angle takeoff and interarterial course, the wall structure with highly abundant elastic fibers that are more flexible tissues among blood vessel components might suggest their vulnerability to compression during the great vessels' systolic expansion in the sympathetic activation induced by the viral infection, leading to fatal myocardial ischemia without physical exertion.

Molecular Alterations in Pediatric Solid Tumors.

Pediatric tumors can be divided into hematologic malignancies, central nervous system tumors, and extracranial solid tumors of bone, soft tissue, or other organ systems. Molecular alterations that impact diagnosis, prognosis, treatment, and familial cancer risk have been described in many pediatric solid tumors. In addition to providing a concise summary of clinically relevant molecular alterations in extracranial pediatric solid tumors, this review discusses conventional and next-generation sequencing-based molecular techniques, relevant tumor predisposition syndromes, and the increasing integration of molecular data into the practice of diagnostic pathology for children with solid tumors.

Micro-CT processing's effects on microscopic appearance of human fetal cardiac samples.

Higher resolution than common computed tomography has been reached through Micro-Computed Tomography (micro-CT) on small samples. Emerging forensic applications of micro-CT are the study of fetal/infant organs and whole fetuses, and their two/three-dimension reconstruction; it allows: to facilitate pathologists' role in the identification of causes of fetal stillbirth and of infant death; to create digital two and/or three-dimension representations of fetal/infant organs and whole fetuses which can be easily discussed in civil and/or penal courts. Micro-CT reconstructs cardiac anatomy of animal and human sample. There are no studies that are specifically aimed to evaluate possible effects of micro-CT processing on cardiac microscopic evaluation. This study analyzed microscopic effects of micro-CT processing on human-fetal-hearts. After processing with Lugol-solution or Microfil-MV-122-injection in coronary branches, fetal hearts underwent micro-CT scan. Then, hearts were microscopically analyzed using hematoxylin/eosin, trichrome, immunohistochemistry (IHC) for actin-protein, and IHC for desmin-intermediate-filament stains. In all cases staining was present in all fields. In all slides, disarranged myocardial proteins with increase of inter filaments and inter cellular spaces was reported. This manuscript allowed to observe post micro-CT appropriate staining and antigenic reactivity, and to identify cytoarchitecture modifications that could compromise slides' microscopic evaluation. It also highlighted a possible role of micro-CT determining this cytoarchitecture phenomenon.

Molecular Alterations in Pediatric Fibroblastic/Myofibroblastic Tumors: An Appraisal of a Next Generation Sequencing Assay in a Retrospective Single Centre Study.

BACKGROUND: Pediatric fibroblastic/myofibroblastic tumors (PFMTs) can be challenging to definitively classify. Large case series or diagnostic updates have not been recently published despite identification of molecular alterations that could improve diagnostic accuracy. Our review of the literature found that over two-thirds of the more than 30 types of PFMTs harbor recurrent molecular alterations. We performed an institutional review of PFMTs to highlight limitations of a predominantly morphological classification, and evaluated the utility of a next-generation sequencing assay to aid diagnosis. METHODS: PFMTs identified over a period of 12 years were reviewed, categorized per the new WHO classification, and tested using the Oncomine Childhood Cancer Research Assay. RESULTS: Eighty-seven specimens from 58 patients were reviewed; 50 were chosen for molecular analysis, 16 (32%) lacking definitive classification. We identified alterations, some novel, in 33% of assayed cases. Expected alterations were identified for most known diagnoses and mutations were identified in 6 of 16 tumors (38%) that were initially unclassified. CONCLUSION: We confirmed a significant subset of PFMTs remain difficult to classify using current criteria, and that a combined DNA/RNA assay can identify alterations in many of these cases, improving diagnostic certainty and suggesting a clinical utility for challenging cases.