Coordinated activities of Myosin Vb isoforms and mTOR signaling regulate epithelial cell morphology during development.

The maintenance of epithelial architecture necessitates tight regulation of cell size and shape. However, mechanisms underlying epithelial cell size regulation remain poorly understood. We show that the interaction of Myosin Vb with Rab11 prevents the accumulation of apically derived endosomes to maintain cell-size, whereas that with Rab10 regulates vesicular transport from the trans-Golgi. These interactions are required for the fine-tuning of the epithelial cell morphology during zebrafish development. Furthermore, the compensatory cell growth upon cell-proliferation inhibition involves a preferential expansion of the apical domain, leading to flatter epithelial cells, an efficient strategy to cover the surface with fewer cells. This apical domain growth requires post-trans-Golgi transport mediated by the Rab10-interacting Myosin Vb isoform, downstream of the mTOR-Fatty Acid Synthase (FASN) axis. Changes in trans-Golgi morphology indicate that the Golgi synchronizes mTOR-FASN-regulated biosynthetic input and Myosin Vb-Rab10 dependent output. Our study unravels the mechanism of polarized growth in epithelial cells and delineates functions of Myosin Vb isoforms in cell size regulation during development.

Patient satisfaction and value based purchasing in hospitals, Odisha, India.

Objective: To examine how a general inpatient satisfaction survey functions as a hospital performance measure. Methods: We conducted a mixed-methods pilot study of the Hospital Consumer Assessment of Health Providers and Systems survey in Odisha, India. We divided the study into three steps: cognitive testing of the survey, item testing with exploratory factor analysis and content validity indexing. Cognitive testing involved 50 participants discussing their interpretation of survey items. The survey was then administered to 507 inpatients across five public hospitals in Odisha, followed by exploratory factor analysis. Finally, we interviewed 15 individuals to evaluate the content validity of the survey items. Findings: Cognitive testing revealed that six out of 18 survey questions were not consistently understood within the Odisha inpatient setting, highlighting issues around responsibilities for care. Exploratory factor analysis identified a six-factor structure explaining 66.7% of the variance. Regression models showed that interpersonal care from doctors and nurses had the strongest association with overall satisfaction. An assessment of differential item functioning revealed that patients with a socially marginalized caste reported higher disrespectful care, though this did not translate into differences in reported satisfaction. Content validity indexing suggested that discordance between experiences of disrespectful care and satisfaction ratings might be due to low patient expectations. Conclusion: Using satisfaction ratings without nuanced approaches in value-based purchasing programmes may mask poor-quality interpersonal services, particularly for historically marginalized patients. Surveys should be designed to accurately capture true levels of dissatisfaction, ensuring that patient concerns are not hidden.

Isolated embryonal rhabdomyosarcoma of the anterior petrous bone in a young child: Focusing on the intra-operative diagnosis and differentials.

OBJECTIVE: Rhabdomyosarcoma is a common soft tissue tumor, but isolated involvement of anterior portion of petrous bone is exceedingly rare. Here, we present a case of embryonal rhabdomyosarcoma involving the anterior petrous without involvement of the mastoid and middle ear. PATIENT: A 6-year-old boy presented with a progressive right side lower motor neuron facial paresis for 1-month duration along with headache and recurrent vomiting episodes. Radiology showed a contrast-enhancing lesion involving the right petrous apex. He underwent craniotomy and excision of the lesion. Based on the frozen section, a diagnosis of rhabdomyosarcoma was rendered, and gross total resection could be achieved. Postoperative course was uneventful. CONCLUSION: Isolated petrous bone involvement of embryonal rhabdomyosarcoma is a rare presentation. Intra-operative frozen section plays a key role in decision making regarding the extent of excision. Hence, a prompt and accurate diagnosis is essential in managing these cases.

Suprasellar masquerader: Chordoid glioma.

BACKGROUND: Chordoid glioma is a rare well-circumscribed glial neoplasm arising in adults and predominantly affects females. Tanycytes of the third ventricle have been proposed as the cell of origin owing to its location. It is characterized by chordoid features with myxoid and inflammatory stroma and recurrent PRKCA p.D463H missense mutation. CASE REPORT: We present two cases (30-year-old female and 45-year-old male) with similar complaints of behavioral change and headache. Midline suprasellar homogeneously enhancing mass was seen on contrast-enhanced magnetic resonance imaging. Histopathology and immunohistochemistry was characteristic of chordoid glioma with cords and clusters of epithelioid cells arranged in a solid pattern. There were variable amounts of myxoid stroma and lymphoplasmacytic infiltrate. No mitosis, necrosis, or brain invasion was noted. The cells expressed strong diffuse positivity for glial fibrillary acid protein (GFAP) and weak nuclear thyroid transcription factor (TTF-1). Epithelial membrane antigen (EMA)and brachyury were negative. Subsequently, the lady underwent gross total excision and died soon after the operation. The male patient received radiotherapy and is currently doing well after 6 months of follow-up. CONCLUSION: The rare occurrence as well as the radiological and morphological overlaps in chordoid gliomas make them a true masquerader. Combination of GFAP and TTF-1 in the immunohistochemical panel can be useful in differential diagnosis. Mainstay of treatment is complete surgical excision, with adjuvant radiotherapy becoming increasingly important.

Idiopathic hypereosinophilic syndrome presenting with stroke.

Hypereosinophilic syndrome (HES) is characterized by eosinophilia associated with organ damage. The disorder has substantial clinical heterogeneity and a highly variable prognosis. This report describes an interesting autopsy case of a 62-year-old lady presenting with itching and stroke-like symptoms. She was diagnosed with an "idiopathic" variant of HES after a thorough exclusion of all known causes. Despite adequate measures, she deteriorated rapidly. At autopsy, acute cerebral infarcts were identified in multiple vascular territories including infarcts in watershed areas. Additionally, her heart showed classic pathological features of eosinophilic myocarditis spanning all three stages.

Clinical, immunological and molecular profiles of DOCK8 deficiency in six patients from a tertiary care centre in North India.

BACKGROUND: Dedicator of cytokinesis protein 8 (DOCK8) deficiency is an autosomal recessive form of combined immunodeficiency. This rare disorder is characterized by an increased predisposition to allergy, autoimmunity and malignancies. OBJECTIVES: To analyse clinical, immunological and molecular profiles of patients with DOCK8 deficiency. METHODS: Clinic records of all patients attending the primary immunodeficiency clinic from 2018 to 2021 were reviewed. Six patients from five families were found to have DOCK8 deficiency. RESULTS: Median age at diagnosis was 7.5 years (range 2-13), with a male/female ratio of 5 : 1. Among the six patients, recurrent eczematous skin lesions were the predominant cutaneous manifestation, present in five patients (83%). Warts and molluscum contagiosum were evident in two patients (33%) and one patient (16%), respectively. Two patients had recalcitrant prurigo nodularis lesions and two had epidermodysplasia verruciformis-like lesions. Food allergies and asthma were reported by one patient each. Of the six patients, recurrent sinopulmonary infections were detected in five (83%). Epstein-Barr virus-driven non-Hodgkin lymphoma with liver metastases was the only case of malignancy, in a 4-year-old boy. IgE was elevated in all patients. Lymphopenia and eosinophilia were observed in three patients (50%) and five patients (83.3%), respectively. Genetic analysis showed DOCK8 pathogenic variants in all patients: homozygous deletion mutations in two patients, compound heterozygous deletion mutations in one, and homozygous nonsense mutations in two. A novel pathogenic homozygous missense variant in the DOCK8 gene was identified in one patient. CONCLUSIONS: DOCK8 deficiency should be considered as a possibility in any patient with early onset eczema, cutaneous viral infections and increased predisposition to allergy, autoimmunity and malignancy.

Uncommon histopathological features of cytomegalovirus encephalitis and measles inclusion body encephalitis on autopsy in two patients with primary immunodeficiency.

PURPOSE: To describe the neuropathological findings in two patients with primary immunodeficiency who had fatal viral encephalitis. MATERIALS AND METHODS: Severe combined immunodeficiency (SCID) was confirmed in case 1 by genetic testing, while case 2 had features suggestive of combined immunodeficiency; however, whole exome sequencing showed no pathogenic variants. Autopsies were performed in both cases after an informed consent. A detailed sampling of the brain including extracranial organs was conducted. Immunohistochemistry and electron microscopy was also performed to confirm the presence of viruses. RESULTS: Besides evidence of cystic encephalomalacia observed in both cases, the brain in case 1 revealed cytomegalovirus (CMV) ventriculoencephalitis accompanied by an exuberant gemistocytic response in the entire white matter. Nuclei of gemistocytes were loaded with several CMV nuclear inclusions, which was confirmed by immunohistochemistry. Case 2 demonstrated features of measles inclusion body encephalitis with several viral inclusions within neurons and astrocytes. Rare giant cells were also seen. Measles virus was confirmed on immunohistochemistry and electron microscopy. Plausibly, there was paucity of microglial nodules in both cases. Superadded bacterial pneumonia with diffuse alveolar damage was also seen in both cases. CONCLUSION: These cases add to the spectrum of unusual histological features of viral encephalitis seen in patients with underlying primary immunodeficiency diseases.

Isolated tracheobronchial mucormycosis: Report of a case and systematic review of literature.

BACKGROUND: Isolated tracheobronchial mucormycosis (ITBM) is an uncommonly reported entity. Herein, we report a case of ITBM following coronavirus disease 2019 (COVID-19) and perform a systematic review of the literature. CASE DESCRIPTION AND SYSTEMATIC REVIEW: A 45-year-old gentleman with poorly controlled diabetes mellitus presented with cough, streaky haemoptysis, and hoarseness of voice 2 weeks after mild COVID-19 illness. Computed tomography and flexible bronchoscopy suggested the presence of a tracheal mass, which was spontaneously expectorated. Histopathological examination of the mass confirmed invasive ITBM. The patient had complete clinical and radiological resolution with glycaemic control, posaconazole, and inhaled amphotericin B (8 weeks). Our systematic review of the literature identified 25 additional cases of isolated airway invasive mucormycosis. The median age of the 26 subjects (58.3% men) was 46 years. Diabetes mellitus (79.2%) was the most common risk factor. Uncommon conditions such as anastomosis site mucormycosis (in two lung transplant recipients), post-viral illness (post-COVID-19 [n = 3], and influenza [n = 1]), and post-intubation mucormycosis (n = 1) were noted in a few. Three patients died before treatment initiation. Systemic antifungals were used in most patients (commonly amphotericin B). Inhalation (5/26; 19.2%) or bronchoscopic instillation (1/26; 3.8%) of amphotericin B and surgery (6/26; 23.1%) were performed in some patients. The case-fatality rate was 50%, primarily attributed to massive haemoptysis. CONCLUSION: Isolated tracheobronchial mucormycosis is a rare disease. Bronchoscopy helps in early diagnosis. Management with antifungals and control of risk factors is required since surgery may not be feasible.

Delayed yet effective response of an endolymphatic sac tumor to radiosurgery: case report focusing on its radio-biological behavior.

Endolymphatic sac tumors (ELST), though benign are locally invasive lesions. Owing to its vascularity, complete surgical resection is often not possible and adjuvant gamma knife radiosurgery (GKRS) is advocated to control tumor growth. These lesions do not uniformly respond to radiation therapy in the initial phase and their early radiobiological course after GKRS is less understood. We discuss a case of residual ELST where a mild increase was noted at 36 months following GKRS and then regressed completely after a decade. This report possibly has the longest follow-up revealing the true efficacy of GKRS in these tumors. ELST shows a variable response in the early years after GKRS. They may remain static, regress or increase in size. One should be aware of these patterns of early radiological responses and a long term follow up is warranted as some lesions may show radiosurgical effectiveness after a long latent period.

Utility of Immunohistochemistry and Immunofluorescence in Determining the Pathogenic Variants of Chronic Granulomatous Disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder of phagocytes due to defects in any of the five subunits of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. An initial diagnosis of CGD is made by flow cytometry-based dihydrorhodamine assay or nitro blue tetrazolium test, which is further confirmed by molecular assays. Expression of five subunits of NADPH oxidase components by either flow cytometric or western blot analysis provides clues toward the potential gene targets which are subsequently confirmed by various genetic assays. Immunohistochemistry (IHC) and immunofluorescence (IF) have never been earlier used to determine the expression of different subunits of NADPH oxidase system. We evaluated the utility of IHC and IF in determining the underlying pathogenic variants of CGD. MATERIALS AND METHODS: Twelve genetically confirmed cases of CGD, comprising of biopsy specimens (n = 6), tissue blocks from autopsy cases (n = 3), and cellblocks of cell pellet prepared from peripheral blood (n = 4) were included. IHC for p67phox and p47phox subunits and IF for cytochrome b558 were performed. RESULTS: All 4 cases with pathogenic variation of NCF2 gene showed loss of expression for p67phox subunit. Two cases with pathogenic variation of NCF1 gene showed loss of expression for p47phox subunit. Five cases, except a single case with CYBB gene pathogenic variation, showed loss of expression for cytochrome b558 on IF. Thus, loss of expression consistently matched with the underlying genetic defects assessed by sequencing. CONCLUSIONS: Our results confirm our hypothesis that IHC and IF are two rapid, economical, pathologist-friendly techniques providing pertinent information regarding the underlying pathogenic variants and such immuno-analysis can be easily performed on the tissue.

Wnt/ß-catenin inhibitor pyrivinium attenuates cisplatin-induced acute kidney injury by possibly reducing platinum uptake and accumulation mediated by reduced organic cation transporter-2 expressions.

Aberrant activation of Wnt/ß-catenin induces renal dysfunction by initiating pro-apoptotic cascades, fibrosis, oxidative and inflammatory burden. This study tested the therapeutic effects of Wnt/ß-catenin inhibitor pyrvinium against cisplatin-induced acute kidney injury (AKI) in rats. Cisplatin was administered at a single dose of 5 mg/kg (i.p.) and renal cisplatin accumulation and uptake in cortical slices were determined after the fifth day by atomic absorption spectroscopy. Levels of pro-inflammatory cytokines were checked by ELISA, and organic cation transporter-2 (OCT-2) transcription and expression in renal tissue were evaluated by RT-PCR and immunohistochemical technique. Cisplatin administration produced renal dysfunction manifested as increase in serum creatinine, blood urea nitrogen, proteinuria, reduced clearance and electrolyte imbalance. Oxidative stress indices, pro-inflammatory cytokines, fibronectin, and caspase-3 activity were elevated in cisplatin-challenged rats. Moreover, increased renal OCT-2 transcription and immunostaining were detected in cisplatin kidneys which resulted in platinum accumulation. Additional docking studies depicted strong interaction between the ß-catenin and OCT-2 protein. These manifestations induced mitochondrial dysfunction, histological damage and fibrosis. Notably, Wnt/ß-catenin inhibitor pyrvinium (60 µg/kg; p.o.) treatment reduced the renal OCT-2 gene transcription causing a decline in platinum levels. Thus, the present study concludes that Wnt/ß-catenin inhibition attenuates cisplatin-induced AKI in rats, partly by down-regulating OCT-2 expression.

Extra-axial, dural-based atypical teratoid/rhabdoid tumor.

Atypical teratoid/rhabdoid tumors (ATRTs) are malignant central nervous system tumors that affect early childhood (< 3 years), and mostly located in the infratentorial space. Owing to an infrequent occurrence, their radiological features have not been completely defined. Nevertheless, these are characteristically intra-axial except for few instances in the cerebellopontine angle region. We describe a case of a 10-year-old boy who harbored an extra-axial, dural-based ATRT in the right parietal region. The lesion was totally excised followed by adjuvant chemo-radiotherapy. At 10-month follow-up, he was well with no recurrence. The report intends to highlight an atypical imaging presentation of ATRT in an older child, and adds to the radiological spectrum. This uncommon pathology should be borne in mind, even in a supratentorial dural-based location.

Seronegative panencephalitis complicated by viral encephalomyelitis in a case of Good's syndrome - a neuropathological report.

BACKGROUND: The role of thymus in the immune cascade of the body is still under active clinical scrutiny. Meanwhile, there is an unravelling of myriad presentations of thymoma with effects on various organ systems. These effects arise both due to autoimmunity or a paraneoplastic process secondary to thymoma. However, an occasional patient can be a conundrum and may give no clue regarding the pathogenesis and etiology of its clinical profile. MATERIAL AND METHODS: We present an enigmatic case of a 30-year-old male presenting with superficial fungal infections followed by multiaxial neurological involvement against a background of thymoma. Extensive workup for bacterial, viral, autoimmune and paraneoplastic etiologies were negative. Thymectomy confirmed thymoma (Type AB) but failed to ameliorate the progression of symptoms. He developed recurrent episodes of severe sepsis which remitted with sensitive antibiotics only to reappear again. Immunological profile showed complete absence of peripheral circulating B-cells with reversal of CD4/CD8 ratio, findings compatible with Good's syndrome. Radiological findings showed only progressive brain atrophy without any hyperintensity. He was also treated with intravenous immunoglobulins but failed to respond with the same. RESULTS: Autopsy revealed features of panencephalitis (neuronophagia, neuronal loss, perivascular lymphocytic cuffing and microglial nodules) with virus particles detected ultrastructurally. Although the distinction between seronegative autoimmune encephalitis versus a viral encephalomyelitis often blurs histologically, we speculated viral encephalomyelitis to have happened toward the latter part of his long illness. To our knowledge, this is a case of Good's syndrome presenting with seronegative autoimmune panencephalitis superimposed with a viral infection.

Pathological role of the calcium-sensing receptor in sepsis-induced hypotensive shock: Therapeutic possibilities and unanswered questions.

Sepsis is a life-threatening disease involving multiorgan dysfunction, prompted by an unregulated host response to infection. Shock is a complication of sepsis in which the circulatory and cellular metabolism anomalies are significant enough to raise the risk of death. Calcium dyshomeostasis occurs during sepsis condition due to imbalance between calcium uptake and excessive release induced by inflammatory cytokines. This calcium imbalance can cause activation of calcium-sensing receptors (CaSRs) located on the surface of T cells and thereby promote release of reactive oxygen species (ROS). The elevated ROS and inflammatory cytokines during sepsis condition have been reported to directly damage the endothelial cells, disrupt the barrier functions that might result in leakage of fluids, and inflammatory cells in tissues Moreover, several evidence have revealed that the calcium mediated activation of CaSR could produce systemic vasodilatory response by stimulating the nitric oxide production and opening of calcium-activated potassium channels, while infusion of its antagonist elevated the blood pressure. These evidence indicate that activation of CaSR during sepsis conditions results in release of ROS and inflammatory cytokines, which could produce an endothelial barrier damage, cardiomyocyte apoptosis. These pathological events could produce loss of fluid in tissues and cardiac dysfunction. Further the direct vasodilatory effects of CaSR activation might add to the shock-like condition. Thus, we hereby propose that inhibition of CaSR could suppress the release of ROS, inflammatory mediators, and thereby prevent the endothelial damage, cardiac dysfunction, and maintain systemic vascular tone.

Infantile Inflammatory Myofibroblastic Tumor of Spleen.

Background: Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm with unknown etiology and recurrent potential. They are widely reported in children and young adults. Nearly 50% of inflammatory myofibroblastic tumor harbor rearrangement in anaplastic lymphoma kinase (ALK) gene with the majority expressing ALK protein. ALK-negative IMTs harbor alteration in ROS1 gene in a subset of cases. Few reports have shown association of IMT with Epstein-Barr virus (EBV). Case report: We report a case of IMT of the spleen in an 18-month-old infant presenting with abdominal distention and failure to thrive. Workup for ALK-1, ROS1, and EBV small-encoded RNA in-situ hybridization using immunohistochemistry was negative. Conclusions: IMT can arise in an infant spleen.

Advanced multiparametric MRI-based scoring for isocitrate dehydrogenase mutation prediction of gliomas.

Purpose: To propose an advanced multiparametric magnetic resonance imaging (MRI)-based scoring system and evaluate its diagnostic accuracy with respect to the isocitrate dehydrogenase (IDH) mutation status of gliomas. Material and methods: This prospective observational study included 50 consecutive patients with suspected gliomas, enrolled for pre-operative MRI. The exclusion criteria were previous surgery, biopsy, or chemo/radiotherapy and contraindications to the gadolinium-based contrasts or MRI acquisition. A standardized brain-MRI protocol using a 3-Tesla machine and 16-channel head coil consisted of pre-contrast axial-T2WI, FLAIR, DTI, 3D-ASL perfusion, SWI, 3D-T1WI, and post-contrast axial-DSC perfusion followed by 3D-T1WI and MR spectroscopy. ROIs were drawn from the tumoral centre, periphery, and peritumoral oedema (3 ROIs for each) followed by normalization using the ROIs over the contralateral normal white matter. The cut-off values for the statistically significant (p <0.05) continuous variables were derived by drawing receiver operating characteristic (ROC) curves. A 7-point "glioma-score" was derived from the 3 categorical (T2/FLAIR-mismatch, contrast enhancement, and intratumoral susceptibility signals) and 4 continuous ROI-based variables (ADC, FA, ASL-CBF, and DSC-CBV). Results: The predictability of IDH mutant status using the multiparametric advanced MRI-based glioma score was statistically significant (sensitivity = 69.23%, specificity = 95.65%, PPV = 94.74%, NPV = 73.33%). A glioma score of more than 4.5 out of 7 predicted the IDH-mutation status with higher specificity and sensitivity compared to each of the individual imaging variables. Conclusions: The advanced multiparametric MRI-based glioma score can predict the IDH-mutation status with high statistical significance.

Liver Abscess in Chronic Granulomatous Disease-Two Decades of Experience from a Tertiary Care Centre in North-West India.

PURPOSE: Most of the literature on liver abscess in chronic granulomatous disease (CGD) emanates from developed countries. Data from developing countries are scarce. In this study, we report clinical features, microbiological profile, and treatment difficulties encountered while managing liver abscesses in patients with CGD at a tertiary care centre in North-West India. METHODOLOGY: Case records of children with CGD and liver abscesses at Pediatric Immunodeficiency Clinic, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India were analyzed. RESULTS: Seven of 68 patients (10.29%) with CGD presented with hepatic abscess. One patient had 2 recurrences. All were males and age-range at presentation was 7 months-22 years. Mutation analysis was carried out in all patients-3 had defects in CYBB gene; 2 in NCF1; 2 in NCF2 gene. Staphylococcus aureus was isolated from 5 patients. Duration of antimicrobial treatment ranged from 3 weeks to 7 months. Open drainage was required in 1 patient, and 1 patient was treated with a prolonged course of prednisolone. Two children succumbed to the illness. CONCLUSIONS: This is the largest reported experience of liver abscesses in patients with CGD from the developing world. Staphylococcus aureus was the commonest pathogen isolated. In our experience, prolonged courses of antimicrobials are usually necessary in these patients. Glucocorticoids can reduce inflammatory response and facilitate early resolution of abscesses in CGD.

Portal vein thrombosis, livedo reticularis, polymicrobial sepsis and high antiphospholipid antibody titers in a newborn: A clinicopathological conference of antiphospholipid-associated neonatal syndrome.

Neonatal Antiphospholipid syndrome (APS) is a rare disease related to transplacental passage of antiphospholipid (aPL) antibodies from the mother or de novo production of aPL in a newborn. Neonatal aPL antibodies have rarely been associated with thrombosis. We describe a 5-week-old infant who developed fever, portal vein thrombosis and livedo reticularis like skin rash. Evaluation for thrombosis revealed high titers of antiphospholipid (aPL) antibodies (dual positive) in the child without any evidence of aPL antibodies in the mother, suggesting a de novo production in the child. Autopsy findings revealed umbilical vein sepsis with thrombosis of portal vein secondary to gram positive cocci which led to multiple liver and lung abscesses. Additionally, the baby had disseminated Cytomegalovirus (CMV) disease (acquired postnatally) involving walls of umbilical and portal vein, liver, lungs, adrenals, pancreas, thymus, and kidneys. Our case highlights the need for testing of aPL in every neonate with arterial or venous thrombosis even when the mother may have no features suggestive of an autoimmune disease.

Diagnostic accuracy and cytomorphological spectrum of Wilms tumour in fine needle aspiration biopsy cytology samples supplemented with cell blocks.

OBJECTIVE: Paediatric malignant renal neoplasms are subjected to neoadjuvant chemotherapy as per Societe Internationale d'Oncologie Pediatrique; International Society of Pediatric Oncology (SIOP) protocol. An accurate tissue diagnosis is required prior to institution of chemotherapy, and hence the aim of this study was to evaluate the diagnostic accuracy of fine needle aspiration biopsy cytology (FNABC) along with cell block histology. MATERIALS AND METHODS: A retrospective audit of all paediatric renal neoplasms diagnosed by FNABC between 2015 and 2019 was performed. Histopathology correlation was done wherever available. WT cases were subjected to detailed cytomorphological evaluation. RESULTS: A total of 121 cases of paediatric renal neoplasms including 109 WT, four clear cell sarcoma, one malignant rhabdoid tumour and three mesoblastic nephroma were evaluated. The age range was 4 weeks to 8 years. FNABC samples were adequate for diagnosis in 120 of 121 cases (99.18%) and a definitive cytological diagnosis was achieved in 117 cases (96.7%). The specificity and sensitivity for a cytopathological diagnosis of WT were 98.7% and 97.4%, respectively. On detailed cytomorphological analysis of 68 histopathology-proven WT, 40 (58.8%) cases were triphasic, 23 (35.3%) were biphasic and four were composed of blastema only. The corresponding cell blocks provided additional information over the conventional smears in 23 (33.8%) cases, with epithelial or mesenchymal elements recognised and evidence of rhabdomyoblastic differentiation. CONCLUSION: FNABC along with cell block histology is highly accurate for diagnosis of WT and other malignant paediatric renal neoplasms and is recommended as the technique of choice in centres with cytopathology expertise for establishing a cellular diagnosis prior to commencement of neoadjuvant chemotherapy.

Role of Cyclin D1 and BCOR Immunohistochemistry in Differentiating Clear Cell Sarcoma of Kidney From its Mimics.

BACKGROUND AND AIM: Clear cell sarcoma of kidney (CCSK) is the second most common pediatric renal malignancy, constituting ∼3% of renal tumors. Due to its morphologic diversity, the diagnosis of CCSK is often challenging. Recent studies have identified internal tandem duplication of BCL6 corepressor (BCOR) gene in CCSKs which coupled with cyclin D1 immunoreactivity, is helpful in differentiating it from its mimics, particularly blastema-rich Wilms tumor (WT), malignant rhabdoid tumor (MRT), and congenital mesoblastic nephroma (CMN). We aimed to evaluate the utility of cyclin D1 and BCOR immunohistochemistry in differentiating CCSK from its morphologic mimics. MATERIALS AND METHODS: Our cohort comprised of 38 pediatric renal tumors which included CCSK (n=18), WT (n=10), MRT (n=5), and CMN (n=5) cases. A detailed clinicopathologic analysis was performed, and tissue microarray were constructed for CCSK and WT, while MRT and CMN tumors were individually stained. RESULTS: The age ranged from 2 months to 16 years with male:female ratio of 3:1. Strong, diffuse nuclear immunoreactivity for cyclin D1 and BCOR was noted in 61% (n=11/18) and 83% (n=15/18) of CCSK, respectively, while it was significantly less in WT (n=3/10 for cyclin D1) (n=2/10 for BCOR). None of the MRT and CMN examples demonstrated any immunoreactivity. Interestingly, only the blastemal component of WTs showed distinct, rare nuclear immunoreactivity for cyclin D1 or BCOR and the combination of these was never positive in a given case. CONCLUSION: Our results provide evidence that concurrent immunopositivity with cyclin D1 and BCOR is helpful in distinguishing CCSK from its morphologic mimics.