Altered expression of activating transcription factor 3 in the hippocampus of patients with mesial temporal lobe epilepsy-hippocampal sclerosis (MTLE-HS)

Aim of the study: Activating Transforming factor 3 (ATF3) is a stress induced gene and closely associated with neuro-inflammation while Transforming growth Factor Beta (TGFβ) signalling is also reported to be involved in neuro-inflammation and hyper-excitability associated with drug resistant epilepsy. Animal model studies indicate the involvement of ATF3 and TGFβ receptors to promote epileptogenesis. Human studies also show that TGFβ signalling is activated in MTLE-HS. However, lack of studies on ATF3 and TGFβRI expression in MTLE-HS patients exists. We hypothesize that ATF3 and TGFβRI might be expressed in hippocampi of patients with MTLE-HS and playing role in epileptogenesis. Materials & methods: Protein expression of ATF3 and TGFβRI was performed by western blotting. Localisation of ATF3 was performed by immunohistochemistry and immunoflorescence. Results: Protein expression of ATF3 and TGFβRI was significantly up-regulated in hippocampi of patients as compared to controls. Also ATF3 IR was significantly expressed in hippocampi of patients and ATF3 was expressed predominantly in cytoplasm as compared to nucleus. No correlation was found between ATF3 expression and epilepsy duration and seizure frequency. Conclusions: ATF3 and TGFβRI are both important players in neuro-inflammation and might potentiate epileptogenesis in these patients.

Extra-skeletal intracranial mesenchymal chondrosarcoma: systematic-literature review

BACKGROUND

Intracranial mesenchymal chondrosarcoma (IMC) is a rare malignant tumor in pediatric population. IMC can present as extra- or intra-axial lesion in pediatric patients, though the former is commoner causing raised intracranial pressure (ICP). Radiological diagnosis is a challenge in these cases, as is it difficult to differentiate these from other extra-axial neoplasms due to the wide differential diagnosis in pediatric population. We aim to systematically review the literature and present a rare case of extraskeletal intracranial mesenchymal chondrosarcoma treated with safe maximal resection.

METHODS

A systematic review of literature was conducted in accordance with PRISMA guidelines. PubMed and Scopus databases were queried using the search terms, "primary intracranial chondrosarcoma", "extraskeletal mesenchymal chondrosarcoma", "mesenchymal chondrosarcoma" and "pediatric". Presentation, surgical management and outcome of a 15-year-old male with an extraskeletal IMC are also described.

RESULTS

The search yielded 25 articles which met the inclusion criteria. These published records consisted of 33 IMC cases with mean age at presentation of 9.81 ± 5.2 years (range 2 months to 18 years). Frontal region was the commonest locations (11, 33.3%). Most common presentation was headache (14, 42.4%). All patients underwent surgical intervention: gross total resection (20, 60.6%), subtotal resection (9, 27.3%) and no extent mentioned (4, 12.1%). No adjuvant therapy was received in 15 patients (45.5%). On latest follow-up, 11 patients (33.3%) are on remission, 5 patients (15.2%) are symptom free, 3 patients (9.1%) had recurrence, 2 patients (6.1%) had metastasis and 9 patients (27.3%) expired.

CONCLUSION

IMC is a rare entity in pediatric population with imaging findings which are non-characteristic leading to its diagnostic challenge. It can masquerade as other extra-axial intracranial neoplasm (meningioma or hemangiopericytoma). Combination of clinico-radiological and pathological examination can help in accurate diagnosis.  Safe Maximal resection followed by radiotherapy is the preferred treatment strategy.

Clinico-radiological parameters, biochemical and molecular alterations predicting remission and recurrence after surgical treatment of corticotroph adenomas - Cushing's disease

OBJECTIVES

Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas is considered to be the gold standard treatment for Cushing's Disease (CD). Even with various recent advances in management, disease persistence and recurrences are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64 to 93%. This study aims to determine various clinical, biochemical, radiological and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-kB and SHH pathway activation and to study the protein expression levels of activation markers of these pathways viz. c-Fos , c-Jun, GLI-1 , pMEK, NR4A1 and p44 in functioning corticotroph pituitary adenomas.

METHODS

From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n=174 surgeries) for Cushing's disease was ambispectively analysed with a median follow up of 8.1 years (1-13.29 years). The preoperative clinical, biochemical, radiological features, operative findings, postoperative clinical and biochemical data, histopathological and molecular profile, were retrieved from electronic records. The patients were followed up to assess the remission status.

RESULTS

Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for paediatric patients and 12 surgeries were performed in patients with Nelson syndrome. In the primary surgery cohort, 74.3% were females and the average age was 28.73 years (SD 10.15). 75% of the patients experienced remission after primary surgery compared to 47.4% in revision surgery. The remission rate in paediatric patients was 55.5%. Post-operative day 1 plasma cortisol (p<0.001; AUC 0.8894 [0.8087-0.9701]) and ACTH (p<0.001; AUC 0.9 [0.7386-1]) levels were seen to be strong independent predictors of remission in the primary surgery cohort. Remission rates after Endoscopic TSS were more than that after microscopic TSS, in patients undergoing primary surgery (81.08% vs 57.14%; p=0.008). Presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (p=0.020). On categorising based on surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of non-remission (OR 38.1 95% CI 4.2-348.3) compared to endoscopically operated patients with adenoma on HPE. Lower immune reactivity score (IRS) of NR4A1 was found to correlate with higher remission rates (p=0.074). However, none of the molecular markers studied viz. c-Fos , c-Jun, GLI-1, pMEK and p44 showed a significant correlation with the preoperative cortisol values.

CONCLUSION

Remission rate after primary surgery is higher as compared to that after revision surgery, and that in paediatric patients is lower as compared to adults. Post-operative day 1 plasma cortisol and ACTH levels are strong independent predictors of remission in the primary surgery cohort. Endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate and thus endoscopy should be the approach of choice in these patients with the goal of identification of an adenoma on histopathological analysis.

MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

Integrated Proteomics and Protein Co-expression Network Analysis Identifies Novel Epileptogenic Mechanism in Mesial Temporal Lobe Epilepsy

Over 50 million people worldwide are affected by epilepsy, a common neurological disorder that has a high rate of drug resistance and diverse comorbidities such as progressive cognitive and behavioural disorders, and increased mortality from direct or indirect effects of seizures and therapies. Despite extensive research with animal models and human studies, limited insights have been gained into the mechanisms underlying seizures and epileptogenesis, which has not translated into significant reductions in drug resistance, morbidities, or mortality. To better understand the molecular signaling networks associated with seizures in MTLE patients, we analyzed the proteome of brain samples from MTLE and control cases using an integrated approach that combines mass spectrometry-based quantitative proteomics, differential expression analysis, and co-expression network analysis. Our analyses of 20 human brain tissues from MTLE patients and 20 controls showed the organization of the brain proteome into a network of 9 biologically meaningful modules of co-expressed proteins. Of these, 6 modules are positively or negatively correlated to MTLE phenotypes with hub proteins that are altered in MTLE patients. Our study is the first to employ an integrated approach of proteomics and protein co-expression network analysis to study patients with MTLE. Our findings reveal a molecular blueprint of altered protein networks in MTLE brain and highlight dysregulated pathways and processes including altered cargo transport, neurotransmitter release from synaptic vesicles, synaptic plasticity, proteostasis, RNA homeostasis, ion transport and transmembrane transport, cytoskeleton disorganization, metabolic and mitochondrial dysfunction, blood micro-particle function, extracellular matrix organization, immune response, neuroinflammation, and cell signaling. These insights into MTLE pathogenesis suggest potential new candidates for future diagnostic and therapeutic development.

Evaluation of KIAA1549::BRAF fusions and clinicopathological insights of pilocytic astrocytomas

BACKGROUND

Pilocytic astrocytoma (PAs) represents a significant portion of childhood primary brain tumors, with distinct histological and radiological features. The prevalence of KIAA1549::BRAF fusion in PAs has been well-established, this study aims to assess the prevalence of KIAA1549::BRAF fusions and explore their associations with tumor characteristics, radiological findings, and patient outcomes in PAs.

METHODS

Histologically confirmed cases of PAs from a 5-year period were included in the study. Demographic, histopathological, and radiological data were collected, and immunohistochemistry was performed to characterize tumor markers. FISH and qRT-PCR assays were employed to detect KIAA1549::BRAF fusions. Statistical analyses were conducted to examine associations between fusion status and various other parameters.

RESULTS

Histological analysis revealed no significant differences in tumor features based on fusion status. However, younger age groups showed higher fusion prevalence. Radiologically, fusion-positive cases were distributed across different tumor subtypes SE, CWE and NCWE. Survival analysis did not demonstrate a significant impact of fusion status on overall survival, however most cases with recurrence and death harboured KIAA1549::BRAF fusion. Of 200 PAs, KIAA1549::BRAF fusions were detected in 64 % and 74 % of cases via qRT-PCR and FISH, respectively. Concordance between the two platforms was substantial (86 %).

CONCLUSION

KIAA1549::BRAF fusions are prevalent in PAs and can be reliably detected using both FISH and qRT-PCR assays. Cost considerations suggest qRT-PCR as a more economical option for fusion detection in routine clinical practice.

Deciphering pancreatic neuroendocrine tumors: Unveiling through circulating small extracellular vesicles

The survival rate over a five-year period for rare pancreatic neuroendocrine tumors (PanNET) is notably lower compared to other neuroendocrine tumors due to late-stage detection, which is a consequence of the absence of suitable diagnostic markers; therefore, there exists a critical need for an early-stage biomarker-specific to PanNETs. This study introduces a novel approach, investigating the impact of small extracellular vesicles (sEV) in PanNET growth and metastasis. As proof of concept, this study shows a correlation between sEV concentration in controls and PanNET. Notably, higher sEV concentrations were observed in PanNETs than in controls (p < 0.0001) with a sensitivity of 100%. Further, apparent differences were observed in the sEV concentrations between controls and grades 1 PanNET (p = 0.005). The expression of sEV markers was confirmed using CD63, TSG101, CD9, Flotillin-1, and GAD65 antibodies. Additionally, the expression of cancer marker BIRC2/cIAP1 (p = 0.002) and autophagy marker Beclin-1 (p = 0.02) were observed in plasma-derived sEVs and PanNET tissue. This study represents the first to indicate the increased secretion of sEV in PanNET patients' blood plasma, proposing potential function of sEV as a new biomarker for early-stage PanNET detection.

Unusual presentation of aneurysmal bone cyst (ABC) in children: pediatric intracranial osteosarcoma with secondary ABC

A 13-year-old female patient presented with painless vision loss and proptosis for 18 months. Imaging findings were highly suggestive of a supraorbital aneurysmal bone cyst (ABC) for which she underwent complete surgical excision. Postoperatively, she developed left hemiparesis. Computed tomography angiography (CTA) revealed right complete internal carotid arterial (ICA) thrombosis. This was managed conservatively, and she improved in hemiparesis over the next 3 weeks. Histopathology report revealed osteosarcoma with secondary ABC, for which she was referred for radiotherapy. At 1.5 months follow-up, the patient's left lower limb power improved to 4 + /5. She was walking without support, and her left upper limb power was 4/5.

Shrinking lung syndrome mimicking diaphragmatic palsy in systemic lupus erythematosus

A 25-year-old woman presented with 1 year of progressive orthopnoea, initially explained as bilateral diaphragmatic paresis caused by seronegative myasthenia gravis. She required assisted ventilation and received pyridostigmine and corticosteroids. She had minimal (particularly proximal) symmetrical tetraparesis with apparent bilateral diaphragmatic weakness, but had normal sensation. Further investigation suggested an overlap myositis with shrinking lung syndrome from systemic lupus erythematosus. She improved following immunosuppression with pulse corticosteroids and rituximab, and at 3 months no longer needed bilevel positive airway pressure support.

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

Malignancy arising in adamantinomatous craniopharyngioma: Report of a rare case with unusual morphologic features

Adamantinomatous craniopharyngioma is a grade 1 tumor that arises in a sellar/suprasellar location. Despite being a grade 1 tumor, there is high recurrence and endocrinal insufficiency. Malignancy arising in craniopharyngioma is extremely rare, has a dismal prognosis, and is currently not included as a separate entity in the World Health Organization Classification of Central Nervous System 5th edition. Here we describe a case of adamantinomatous craniopharyngioma and its malignant counterpart. The malignant part had unique histomorphology and basaloid cells with pseudoglandular architecture and a myxoid background. It bore a striking resemblance to adenoid cystic carcinoma. Both the benign and malignant counterparts were beta-catenin and SOX-2 positive, providing proof of the malignant part arising from the benign part. Tumors like squamous cell carcinoma and odontogenic ghost cell carcinoma have been described in cranipharyngioma. This case study is the first to describe this unique morphology of adenoid cystic carcinoma-like features. The possibility of adenoid cystic carcinoma was excluded by immunohistochemistry.

Spinal astroblastoma, MN1 altered in 3-year-old child: An uncommon tumor at an unusual site

Astroblastoma is an uncommon circumscribed glial tumor mostly involving the cerebral hemisphere. The characteristic molecular alteration is meningioma (disrupted in balanced translocation) 1 (MN1) rearrangement. No definite World Health Organization grade has been assigned as both low- and high-grade tumors are known to occur. Tumors in the spine are extremely rare; to date only three cases have been reported in the literature. A vigilant microscopy and ancillary testing aid in diagnosis when the tumors present in unusual locations, as in our case. The prompt differentiation of this tumor from its mimickers is a mandate as modalities of management are different and not clearly established.

Utility of Simple and Non-Invasive Strategies Alternative to Inferior Petrosal Sinus Sampling and Peripheral CRH Stimulation in Differential Diagnosis of ACTH-Dependent Cushing Syndrome

We aimed to evaluate the utility of simple, cost-effective, and non-invasive strategies alternative to BIPSS and peripheral CRH stimulation in differential diagnosis of ACTH-dependent CS. First, we performed ROC analysis to evaluate the performance of various tests for differential diagnosis of ACTH-dependent CS in our cohort (CD, n=76 and EAS, n=23) and derived their optimal cut-offs. Subsequently, combining various demographic (gender), clinical (hypokalemia), biochemical (plasma ACTH, HDDST, peripheral CRH stimulation) and imaging (MRI pituitary) parameters, we derived non-invasive models with 100% PPV for CD. Patients with pituitary macroadenoma (n=14) were excluded from the analysis involving non-invasive models. Relative percent ACTH (AUC: 0.933) and cortisol (AUC: 0.975) increase on peripheral CRH stimulation demonstrated excellent accuracy in discriminating CD from EAS. Best cut-offs for CD were plasma ACTH<97.3 pg/ml, HDDST≥57% cortisol suppression, CRH stimulation≥77% ACTH increase and≥11% cortisol increase. We derived six models that provided 100% PPV for CD and precluded the need for BIPPS in 35/85 (41.2%) patients with ACTH-dependent CS and no macroadenoma (in whom BIPSS would have otherwise been recommended). The first three models included basic parameters and avoided both peripheral CRH stimulation and BIPSS in 19 (22.4%) patients, while the next three models included peripheral CRH stimulation and avoided BIPSS in another 16 (18.8%) patients. Using simple and non-invasive alternative strategies, BIPSS can be avoided in 41% and peripheral CRH stimulation in 22% of patients with ACTH-dependent CS and no macroadenoma; such patients can be directly referred for a pituitary surgery.

Metabolic imaging in recurrent gliomas: comparative performance of 18F-FDOPA, 18F-fluorocholine and 18F-FDG PET/CT

PURPOSE

The aim of this study was to directly evaluate glucose, amino-acid and membrane metabolism in tumor cells for diagnosis and prognostication of recurrent gliomas.

METHODS

Fifty-five patients (median age = 36 years; 33 men) with histologically proven gliomas and suspected recurrence were prospectively recruited and underwent 18F-FDG (Fluorodeoxyglucose), 18F-FDOPA (fluorodopa) and 18F-Fluorocholine-PET/CT. Images were evaluated by two physicians visually and quantitatively [lesion-SUVmax, tumor (T) to gray-matter (G) and metabolically-active tumor volumes (MTV)]. After median follow-up of 51.5 months, recurrence was diagnosed in 49 patients. Thirty-one patients died with a median survival of 14 months.

RESULTS

Diagnostic-accuracies for 18F-FDOPA, 18F-Fluorocholine,18F-FDG and contrast-enhanced-MRI were 92.7% (95% CI 82.7-97.1), 81.8% (69.7-89.8), 45.5% (33.0-58.5) and 44.7% (30.2-60.3), respectively. Among the 20 lesions, missed by MRI; 18F-FDOPA, 18F-Fluorocholine and 18F-FDG were able to detect 19, 14 and 4 lesions. Corresponding area-under-the-curves (T/G ratios) were 0.817 (0.615-1.000), 0.850 (0.736-0.963) and 0.814 (0.658-0.969), when differentiating recurrence from treatment-induced changes. In univariate-survival-analysis, 18F-FDOPA-T/G, visually detectable recurrence in 18F-FDG, 18F-FDOPA-MTV, cell-lineage and treatment-type were significant parameters. In Multivariate-Cox-regression analysis, 18F-FDOPA-MTV [HR = 1.009 (1.001-1.017); P  = 0.024 (~0.9% increase in hazard for every mL increase of MTV)] and cell-lineage [3.578 (1.447-8.846); P  = 0.006] remained significant. 18F-FDOPA-MTV cutoff <29.59 mL predicted survival higher than 2 years. At cutoff ≥29.59 mL, HR at 2 years was 2.759 (1.310-5.810).

CONCLUSION

18F-FDOPA-PET/CT can diagnose recurrence with high accuracy and MTV predicts survival. 18F-Fluorocholine is a good alternative. Higher 18F-FDG uptake is an adverse prognostic indicator.

Receptor tyrosine kinase gene expression profiling of orbital rhabdomyosarcoma unveils MET as a potential biomarker and therapeutic target

Receptor tyrosine kinases (RTKs) serve as molecular targets for the development of novel personalized therapies in many malignancies. In the present study, expression pattern of receptor tyrosine kinases and its clinical significance in orbital RMS has been explored. Eighteen patients with histopathologically confirmed orbital RMS formed part of this study. Comprehensive q-PCR gene expression profiles of 19 RTKs were generated in the cases and controls. The patients were followed up for 59.53 ± 20.93 years. Clustering and statistical analysis tools were applied to identify the significant combination of RTKs associated with orbital rhabdomyosarcoma patients. mRNA overexpression of RTKs which included MET, AXL, EGFR was seen in 60-80% of cases; EGFR3, IGFR2, FGFR1, RET, PDGFR1, VEGFR2, PDGFR2 in 30-60% of cases; and EGFR4, FGFR3,VEGFR3 and ROS,IGFR1, EGFR1, FGFR2, VEGFR1 in 10-30% of cases. Immunoexpression of MET was seen in 89% of cases. A significant association was seen between MET mRNA and its protein expression. In all the cases MET gene expression was associated with worst overall survival (P = 0.03).There was a significant correlation of MET mRNA expression with RET, ROS, AXL, FGFR1, FGFR3, PDGFR1, IGFR1, VEGFR2, and EGFR3 genes. Association between MET gene and collective expression of RTKs was further evaluated by semi-supervised gene cluster analysis and Principal component analysis, which showed well-separated tumor clusters. MET gene overexpression could be a useful biomarker for identifying high risk orbital rhabdomyosarcoma patients. Well-separated tumor clusters confirmed the association between MET gene and collective expression of RTK genes. Therefore, the therapeutic potential of multi-kinase inhibitors targeting MET and the 9 other significant RTKs needs to be explored.

Metastatic alveolar soft part sarcoma of the kidney in a young female

A 19-year-old female presented with left flank discomfort and swelling. Imaging revealed a large mass arising from the left kidney, and radical nephrectomy confirmed the diagnosis of alveolar soft part sarcoma (ASPS) based on histopathological and ultrastructural examination. Postoperatively, positron emission tomography-computerized tomography showed lung metastasis and renal bed recurrence. Sunitinib was initiated for metastatic ASPS. This case underscores challenges in diagnosing and managing ASPS, highlighting the role of tyrosine kinase inhibitors. Multidisciplinary care and vigilant follow-up are crucial for rare tumors such as ASPS.

Intracranial myeloid sarcoma as the first presentation of acute myeloid leukemia and literature review

INTRODUCTION

Intracranial myeloid sarcoma is a rare extramedullary presentation of acute myeloid leukemia (AML). It can involve the meninges and ependyma presenting as extra-axial mass lesion. Rarely, it can also invade the brain parenchyma. It is commonly seen in children. It is usually misdiagnosed due to its close resemblance to other intracranial tumors (meningioma, metastasis, Ewing's sarcomas, and lymphoma). These are underdiagnosed if they precede the diagnosis of leukemia.

CASE REPORT

A 7-year-old boy with isolated intracranial myeloid sarcoma who presented with raised intracranial pressure (ICP) which was successfully managed by surgical excision.

CONCLUSION

Isolated intracranial myeloid sarcoma is a rare presentation of AML. Leukemia can be diagnosed early during the postoperative period and can be started on therapy timely. These patients requires regular follow-ups (clinical, laboratory and radiological) to detect relapses early.

C11orf95-RELA, YAP1-MAMLD1, and YAP1-FAM118B Fusion Negative Anaplastic Ependymoma with Lipogenic Differentiation

Lipogenic differentiation in ependymoma is an infrequent occurrence with very few reported cases. The grading was done solely based on the histomorphology and molecular subtyping was not described in such ependymomas. New molecular classification divided ependymomas in nine different subgroups, of which supratentorial location tumor usually exhibits C11orf95-RELA, YAP1-MAMLD1, and YAP1-FAM118B fusion proteins. A 46-year-old female presented with headache and right-sided parapresis. Radilogy revealed a large intraxial left parietooccipital mass lesion, which histologically and immuohistochemically confirmed as anaplastic ependymoma with extensive lipogenic changes. The ependymal origin of the tumor was corroborated by the immunohistochemistry and ultrastructural studies. Molecular studies for C11orf95-RELA, YAP1-MAMLD1, and YAP1-FAM118B fusion proteins were negative. This is the first documentation of fusion negative supratentorial anaplastic ependymoma with lipogenic differentiation. This novel finding needs further reinforcement by similar studies to identify its impact on the disease outcome.

Spinal atypical teratoid rhabdoid tumor-narrative review and report of a rare case managed with multimodality approach

BACKGROUND

Spinal atypical teratoid rhabdoid tumor (AT/RT) is an extremely rare tumor and represents less than 2% of all AT/RTs.

METHODS

Available medical literature on spinal AT/RT in English was retrieved from PubMed and comprehensively reviewed. Clinical presentation, diagnosis, management, prognosis, and outcome in patients with spinal AT/RT have been elucidated by citing a case of extradural AT/RT of the cervicodorsal spine.

RESULTS

The age at presentation is usually less than 3 years. The most common site is the cervicodorsal spine. The most frequent tumor location is intradural extramedullary. A contrast-enhanced magnetic resonance imaging (MRI) of the entire neuraxis is the imaging modality of choice. The incidence of leptomeningeal dissemination is high (15-30%). Histopathological examination shows an admixture of primitive neuroectodermal, mesenchymal, and epithelial elements along with rhabdoid cells. Loss of SMARCB1/INI1 is considered pathognomonic of AT/RT. Maximal safe resection of tumor is the initial management of choice. Thereafter focal radiotherapy for localized tumor or craniospinal irradiation for leptomeningeal dissemination should be considered. Post-operative intensive polychemotherapy including intrathecal and high-dose chemotherapy (with autologous stem cell rescue) is usually considered to optimize survival. Typically, the time to recurrence and overall survival are less than 6 and 12 months, respectively. However, with judicious multimodality management long-term survivors are increasingly being recognized. The illustrative patient was a 18-month-old girl diagnosed with extradural AT/RT of the cervicodorsal spine (C3-D1), who was managed with maximal safe resection of tumor, multiagent chemotherapy (ICE-ifosfamide, carboplatin, etoposide) and focal RT to the tumor bed-50.4 Gy/28 fractions/5.5 weeks. At the last follow-up visit, 30 months after surgery, she had complete clinicoradiological response.

CONCLUSION

Multimodal treatment comprising maximal safe resection of tumor, multiagent chemotherapy (ICE), and focal RT can lead to successful outcome in patients with localized spinal AT/RT, under the age of 3 years.

Splenic Lymphomas: A Tertiary Care Center Experience and Review of Literature

Primary splenic lymphomas are rare with the majority of lymphomas in spleen being secondary to an extra-splenic lymphoma. We aimed to analyze the epidemiological profile of the splenic lymphoma and review the literature. This was a retrospective study including all splenectomies and splenic biopsies from 2015 to September 2021. All the cases were retrieved from Department of Pathology. Detailed histopathological, clinical and demographic evaluation was done. All the lymphomas were classified according to WHO 2016 classification. A total of 714 splenectomies were performed for a variety of benign causes, as part of tumor resections and for the diagnosis of lymphoma. Few core biopsies were also included. A total of 33 lymphomas diagnosed in the spleen, primary splenic lymphomas constituted 84.84% (n = 28) of the cohort with 5 (15.15%) having the primary site elsewhere. The primary splenic lymphomas constituted 0.28% of all the lymphomas arising at various sites. Adult population (19-65 years) formed the bulk (78.78%) with a slight male preponderance. Splenic marginal zone lymphomas (n = 15, 45.45%) comprised of major proportion of cases followed by primary splenic diffuse large B-cell lymphoma (n = 4, 12.12%). Splenectomy was the main course of treatment for SMZL with a good overall outcome, with chemotherapy ± radiotherapy forming the mainstay in other lymphomas. Lymphomas in spleen can be infiltrative or a primary, hence proper clinic-radiological and pathological evaluation is required. Appropriate management is guided by the precise and detailed evaluation by the pathologist, requiring understanding of the same.

Management protocol and surgical techniques for MRI-Negative Cushing's disease: a series of 6 cases

Up to 40% of Cushing's disease (CD) patients show no evidence of an adenoma on dynamic contrast-enhanced MRI. Inferior petrosal sinus sampling (IPSS) remains the gold standard for diagnosis in these patients. Remission rates in MRI-Negative CD are far less at 50%-71%, compared with patients in whom an adenoma is identified on MRI. Endoscopic endonasal transsphenoidal surgery is the surgical approach of choice in these cases. Various adjuncts can be used to localize an adenoma. In this video, the authors highlight their additional usage of pituitary perfusion MRI for identification of the adenoma. They present their stepwise management algorithm and surgical techniques for sellar and suprasellar exploration in 6 cases of MRI-Negative CD operated on by the senior author (A.S.). The video can be found here: https://stream.cadmore.media/r10.3171/2023.4.FOCVID2318.

RNA Sequencing of Intraoperative Peritumoral Tissues Reveals Potential Pathways Involved in Glioma-Related Seizures

Tumor-induced changes in the peritumoral neocortex play a crucial role in generation of seizures. This study aimed to investigate the molecular mechanisms potentially involved in peritumoral epilepsy in low-grade gliomas (LGGs). Intraoperative peritumoral brain tissues resected from LGG patients with seizures (pGRS) or without seizures (pGNS) were used for RNA sequencing (RNA-seq). Comparative transcriptomics was performed to identify differentially expressed genes (DEGs) in pGRS compared to pGNS using deseq2 and edgeR packages (R). Gene set enrichment analysis (GSEA) using Gene Ontology terms and Kyoto Encyclopedia of Genes & Genomes (KEGG) pathways was performed using the clusterProfiler package (R). The expression of key genes was validated at the transcript and protein levels in the peritumoral region using real-time PCR and immunohistochemistry, respectively. A total of 1073 DEGs were identified in pGRS compared to pGNS, of which 559 genes were upregulated and 514 genes were downregulated (log2 fold-change ≥ 2, padj < 0.001). The DEGs in pGRS were highly enriched in the "Glutamatergic Synapse" and "Spliceosome" pathways, with increased expression of GRIN2A (NR2A), GRIN2B (NR2B), GRIA1 (GLUR1), GRIA3 (GLUR3), GRM5, CACNA1C, CACNA1A, and ITPR2. Moreover, increased immunoreactivity was observed for NR2A, NR2B, and GLUR1 proteins in the peritumoral tissues of GRS. These findings suggest that altered glutamatergic signaling and perturbed Ca2+ homeostasis may be potential causes of peritumoral epilepsy in gliomas. This explorative study identifies important genes/pathways that merit further characterization for their potential involvement in glioma-related seizures.

Pediatric Adrenocortical Neoplasms: A Study Comparing Three Histopathological Scoring Systems

Adrenocortical neoplasms are rare in childhood. Their histopathological categorization into benign and malignant is often challenging, impacting further management. While the AFIP/Wieneke scoring system is widely used for the prognostic classification of these tumors, it has limitations. Few other tumor scoring systems have evolved over the past few years. These have been validated in adults but not yet in pediatric patients. We evaluated a cohort of pediatric adrenocortical neoplasms to assess the applicability of AFIP/Wieneke criteria and the recently introduced Helsinki score and reticulin algorithm in predicting clinical outcomes. A tumor was considered 'clinically aggressive' in the presence of any of the following: metastases, recurrence, progressive disease, or death due to disease. Cases without any such event were considered 'clinically good'. Event-free survival time was the duration from the date of clinical presentation to any post-operative adverse event. For overall survival analysis, the endpoint was either the last follow-up or death due to disease.Using ROC curve analysis, the obtained cut-off Helsinki score of 24 could stratify the cases into two prognostically relevant groups. Survival analysis showed significant differences in the event-free and overall survival of these two groups of patients, validating the proposed cut-off. None of the three histopathological scoring systems could predict an unfavorable outcome with 100% accuracy. All showed a sensitivity of ≥ 80%, with the reticulin algorithm achieving 100% sensitivity. The specificity and accuracy of the AFIP/Wieneke criteria were the lowest (62.5% and 73.08%, respectively). While the Helsinki score (at the cut-off score of 24) and the reticulin algorithm had similar accuracy rates (80.77%, and 80%, respectively), the specificity of the former was higher (81.25%) than the latter (68.75%). A separate analysis revealed that the Ki-67 index at a cut-off of 18% had a sensitivity of 80% and a specificity of 81.25% for predicting an unfavorable outcome.

Ubiquitin specific peptidase 37 and PCNA interaction promotes osteosarcoma pathogenesis by modulating replication fork progression

BACKGROUND

Osteosarcoma is a type of bone cancer that predominantly affects young individuals, including children and adolescents. The disease progresses through heterogeneous genetic alterations, and patients often develop pulmonary metastases even after the primary tumors have been surgically removed. Ubiquitin-specific peptidases (USPs) regulate several critical cellular processes, such as cell cycle progression, transcriptional activation, and signal transduction. Various studies have revealed the significance of USP37 in the regulation of replication stress and oncogenesis.

METHODS

In this study, the Cancer Genome Atlas (TCGA) database was analyzed to investigate USP37 expression. RNA sequencing was utilized to assess the impact of USP37 overexpression and depletion on gene expression in osteosarcoma cells. Various molecular assays, including colony formation, immunofluorescence, immunoprecipitation, and DNA replication restart, were employed to examine the physical interaction between USP37 and PCNA, as well as its physiological effects in osteosarcoma cells. Additionally, molecular docking studies were conducted to gain insight into the nature of the interaction between USP37 and PCNA. Furthermore, immunohistochemistry was performed on archived tissue blocks from osteosarcoma patients to establish a correlation between USP37 and PCNA expression.

RESULTS

Analysis of the TCGA database revealed that increased expression of USP37 was linked to decreased progression-free survival (PFS) in osteosarcoma patients. Next-generation sequencing analysis of osteosarcoma cells demonstrated that overexpression or knockdown of USP37 led to the expression of different sets of genes. USP37 overexpression provided a survival advantage, while its depletion heightened sensitivity to replication stress in osteosarcoma cells. USP37 was found to physically interact with PCNA, and molecular docking studies indicated that the interaction occurs through unique residues. In response to genotoxic stress, cells that overexpressed USP37 resolved DNA damage foci more quickly than control cells or cells in which USP37 was depleted. The expression of USP37 varied in archived osteosarcoma tissues, with intermediate expression seen in 52% of cases in the cohort examined.

CONCLUSION

The results of this investigation propose that USP37 plays a vital role in promoting replication stress tolerance in osteosarcoma cells. The interaction between USP37 and PCNA is involved in the regulation of replication stress, and disrupting it could potentially trigger synthetic lethality in osteosarcoma. This study has expanded our knowledge of the mechanism through which USP37 regulates replication stress, and its potential as a therapeutic target in osteosarcoma merits additional exploration.

Abstract 335: Ubiquitin Specific Peptidase 37promotes Osteosarcoma oncogenesis by interacting with PCNA and impacting constitutive replication fork movement

Osteosarcoma is the heterogeneous primary malignancy of bone which is most commonly found among children and adolescents. Recent data related to treatment of osteosarcoma indicates the lack information about the progression of the disease. Osteosarcoma has been a challenge for the oncologist because even after surgical removal of primary tumors many patients go on to develop pulmonary metastasis. Protein deubiquitination controls many intracellular processes, including cell cycle progression, transcriptional activation, and signal transduction. Ubiquitin specific peptidases (USPs) remove ubiquitin tags from target proteins to alter protein configuration and function. Recent studies have revealed that Ubiquitin specific peptidase 37 (UPS37) regulates replication stress by regulating important protein involved in several important cellular functions. Analysis of TCGA data indicated that overexpression of USP37 correlated with reduced progression free survival (PFS) in osteosarcoma patients. Next generation sequencing (NGS) analysis of osteosarcoma cells indicated that distinct set of genes were altered on overexpression or knockdown of USP37. Our data indicate that USP37 overexpression confers survival advantage while its depletion enhances sensitivity for cell killing in osteosarcoma cells due to replication stress. USP37 overexpressing cells were able to resolve DNA damage foci much more rapidly than the control cells or cells in which USP37 was depleted in response to genotoxic stress. USP37 depletion results in reduced resolution of γ H2AX and 53BP1 DNA damage foci and increase in number of collapsed replication fork which indicates the reduced ability of cells to carry out constitutive DNA replication. USP37 was found to interact with PCNA (Proliferative cell nuclear antigen). Interestingly docking studies indicated that USP37 and PCNA interacted with stronger affinity in presence of double stranded DNA through different residues. We further correlated our data with archived tissue blocks of osteosarcoma patients by analyzing if USP37 and PCNA expression colocalized. Present data suggests that USP37 is required for tolerance of replication stress as it interacts with PCNA which is required to dock additional replication factors and stabilize DNA replication fork. The current data provides new mechanistic details for the regulation of replication stress by USP37 which merits the development of targeting strategies to explore its therapeutic potential in osteosarcoma by inducing synthetic lethality.

Citation Format: Ravi Chauhan, Lakshay Malhotra, Ashna Gupta, Ajaz Bhat, Gunjan Dagar, Tariq Masoodi, Muzafar A. Macha, Ethayathulla Abdul Samath, Atul Batra, Mehar Chand Sharma, Mohammad Haris, Ammira Al-Shabeeb Akil, Tej K. Pandita, Shahab Uddin, Mayank Singh. Ubiquitin Specific Peptidase 37promotes Osteosarcoma oncogenesis by interacting with PCNA and impacting constitutive replication fork movement. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 335.

Correlation of age at seizure onset with GABAA receptor subunit and chloride Co-transporter configuration in Focal cortical dysplasia (FCD)

Focal cortical dysplasia (FCD) represents a group of malformations of cortical development, which are speculated to be related to early developmental defects in the cerebral cortex. According to dysmature cerebral development hypothesis of FCD altered GABAA receptor function is known to contribute to abnormal neuronal network. Here, we studied the possible association between age at seizure onset in FCD with the subunit configuration of GABAA receptors in resected brain specimens obtained from patients with FCD. We observed a significantly higher ratio of α4/α1 subunit-containing GABAA receptors in patients with early onset (EO) FCD as compared to those with late onset (LO) FCD as is seen during the course of development where α4-containing GABAA receptors expression is high as compared to α1-containing GABAA receptors expression. Likewise, the influx to efflux chloride co-transporter expression of NKCC1/KCC2 was also increased in patients with EO FCD as seen during brain development. In addition, we observed that the ratio of GABA/Glutamate neurotransmitters was lower in patients with EO FCD as compared to that in patients with LO FCD. Our findings suggest altered configuration of GABAA receptors in FCD which could be contributing to aberrant depolarizing GABAergic activity. In particular, we observed a correlation of age at seizure onset in FCD with subunit configuration of GABAA receptors, levels of NKCC1/KCC2 and the ratio of GABA/Glutamate neurotransmitters such that the patients with EO FCD exhibited a more critically modulated GABAergic network.

1146 SLEEP DEPRIVATION INDUCES AGEING-LIKE CHANGES IN ANTIGRAVITY MUSCLES OF YOUNG ADULT MALE WISTAR RATS

Introduction

Poor muscle health is associated with a series of chronic and metabolic conditions that are prevalent in individuals who chronically experience poor-quality sleep. But there is no study deciphering the role of sleep deprivation on muscle ageing. Therefore, in the present study we have measured the ultrastructure, histopathology, and oxidative stressors in soleus muscle of wistar rat after sleep deprivation and recovery sleep.

Material and Methods

The experiments were conducted in 18 rats of three groups. Group I rats had normal sleep wake cycle, Group II rats were subjected to 24 h sleep deprivation (SD) by gentle handling method1 and Group III rats had recovery sleep after 24 h SD. At the end of the sleep, sleep deprivation and recovery period, soleus muscle tissue was collected for ultrastructural, histological and oxidative stress markers. Oxidative damage was assessed by lipid peroxidation, catalase activity, reduced glutathione and nuclear labelling of 8-OHdG. The study was conducted as per the guidelines of the Institutional Animal Ethics Committee (960/IAEC/16).

Results

The data demonstrated that SD leads to ultrastructural changes in soleus muscle which includes sarcolemmal and mitochondrial alterations. In case of histopathological and histomorphological changes there was signs of tissue degeneration, inflammatory infiltrate in type I fibres and muscle atrophy was observed in soleus muscles. There was significant increase in level of 8-OHdG (p=0.02) and malondialdehyde in 24h SD (p=0.02) than control and recovery sleep groups. Moreover, the catalase activity and reduced glutathione level was significantly decreased in 24h SD group (p≤0.02) than control and recovery sleep.

Conclusion

24hr sleep deprivation leads to an ageing like state in the skeletal muscle, which was recovered after sleep rebound.

Formulation and validation of a baseline prognostic score for osteosarcoma treated uniformly with a non-high dose methotrexate-based protocol from a low middle income healthcare setting: a single centre analysis of 594 patients

Introduction

The outcomes of osteosarcoma in low middle income countries (LMICs) are different due to patients presenting in advanced stages, resource constraints and the use of non-high-dose-methotrexate (HDMTX)-based regimens. This study derived and validated a prognostic score for osteosarcoma that integrates biologic and social factors and is tailored for patients from an LMIC setting using a non-HDMTX-based protocol.

Materials and methods

A retrospective study including osteosarcoma patients enrolled for treatment at a single tertiary care centre in India between 2003-19 was conducted. Baseline biologic and social characteristics were extracted from medical records and survival outcomes were noted. The cohort was randomised into a derivation and validation cohort. Multivariable Cox regression was used to identify baseline characteristics that were independently prognostic for survival outcomes in the derivation cohort. A score was derived from the prognostic factors identified in the derivation cohort and further validated in the validation cohort with estimation of its predictive ability.

Results

594 patients with osteosarcoma were eligible for inclusion in the study. Around one-third of the cohort had metastatic disease with 59% of the patients residing in rural areas. The presence of metastases at baseline (HR 3.39; p<0.001; score=3), elevated serum alkaline phosphatase (SAP) >450 IU/L (HR 1.57; p=0.001; score=1) and baseline tumour size > 10 cm (HR 1.68; p<0.001; score=1) were identified to be independent factors predicting inferior event free survival (EFS) and were included in development of the prognostic score. Patients were categorized as low risk (score 0), intermediate risk (score 1-3) and high risk (4-5). Harrell's c-indices for the score were 0.682, 0.608 and 0.657 respectively for EFS in the derivation, validation and whole cohort respectively. The timed AUC of ROC was 0.67 for predicting 18-month EFS in the derivation, validation and whole cohorts while that for 36-month EFS were 0.68, 0.66 and 0.68 respectively.

Conclusions

The study describes the outcomes among osteosarcoma patients from an LMIC treated uniformly with a non-HDMTX-based protocol. Tumor size, baseline metastases and SAP were prognostic factors used to derive a score with good predictive value for survival outcomes. Social factors did not emerge as determinants of survival.

Non-invasive intravoxel incoherent motion MRI in prediction of histopathological response to neoadjuvant chemotherapy and survival outcome in osteosarcoma at the time of diagnosis

BACKGROUND

Early prediction of response to neoadjuvant chemotherapy (NACT) is important to aid personalized treatment in osteosarcoma. Diffusion-weighted Intravoxel Incoherent Motion (IVIM) MRI was used to evaluate the predictive value for response to NACT and survival outcome in osteosarcoma.

METHODS

Total fifty-five patients with biopsy-proven osteosarcoma were recruited prospectively, among them 35 patients were further analysed. Patients underwent 3 cycles of NACT (Cisplatin + Doxorubicin) followed by surgery and response adapted adjuvant chemotherapy. Treatment outcomes were histopathological response to NACT (good-response ≥ 50% necrosis and poor-response < 50% necrosis) and survival outcome (event-free survival (EFS) and overall survival (OS)). IVIM MRI was acquired at 1.5T at baseline (t0), after 1-cycle (t1) and after 3-cycles (t2) of NACT. Quantitative IVIM parameters (D, D*, f & D*.f) were estimated using advanced state-of-the-art spatial penalty based IVIM analysis method bi-exponential model with total-variation penalty function (BETV) at 3 time-points and histogram analysis was performed.

RESULTS

Good-responders: Poor-responders ratio was 13 (37%):22 (63%). EFS and OS were 31% and 69% with 16.27 and 25.9 months of median duration respectively. For predicting poor-response to NACT, IVIM parameters showed AUC = 0.87, Sensitivity = 86%, Specificity = 77% at t0, and AUC = 0.96, Sensitivity = 86%, Specificity = 100% at t1. Multivariate Cox regression analysis showed smaller tumour volume (HR = 1.002, p = 0.001) higher ADC-25^th-percentile (HR = 0.047, p = 0.005) & D-Mean (HR = 0.1, p = 0.023) and lower D*-Mean (HR = 1.052, p = 0.039) were independent predictors of longer EFS (log-rank p-values: 0.054, 0.0034, 0.0017, 0.0019 respectively) and non-metastatic disease (HR = 4.33, p < 10^-3), smaller tumour-volume (HR = 1.001, p = 0.042), lower D*-Mean (HR = 1.045, p = 0.056) and higher D*.f-skewness (HR = 0.544, p = 0.048) were independent predictors of longer OS (log-rank p-values: < 10^-3, 0.07, < 10^-3, 0.019 respectively).

CONCLUSION

IVIM parameters obtained with a 1.5T scanner along with novel BETV method and their histogram analysis indicating tumour heterogeneity were informative in characterizing NACT response and survival outcome in osteosarcoma.

TCL-306 Application of the Proposed Immunohistochemistry Algorithm for the Prognostication of GATA3 and TBX21 Subtypes of Peripheral T-Cell Lymphoma, Not Otherwise Specified

CONTEXT

Recent molecular studies have indicated the varied oncogenic pathways resulting in the subtypes of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS), which affect prognosis and may have predictive value.

OBJECTIVE

To evaluate the immunohistochemistry (IHC) algorithm (Amador et al.) for the subtyping of PTCL, NOS and ascertain their relevance with correlation to the clinicopathological profile.

DESIGN

This 7-year (2015-2021) ambispective study included 43 patients with diagnoses of PTCL, NOS from the archives of the Department of Pathology (AIIMS, New Delhi). IHC for transcription factors GATA3 (>50% immunopositivity considered positive) and TBX21 (>20%) and their target proteins CCR4 (>50%) and CXCR3 (>20%) was performed followed by subtyping by two pathologists. Detailed clinicopathological correlation was done.

MAIN OUTCOME MEASURES

The association between the subtypes and clinical factors (demographics, performance status, organomegaly, IPI/PIT score, stage, marrow involvement), histologic features (monomorphous/polymorphous population), and survival (overall and progression-free survival) was analyzed.

RESULTS

With the application of the algorithm by Amador et al., the cases were categorized into the subtypes GATA3 (18), TBX21 (13), and unclassifiable (7). There was no significant association observed with the clinical parameters of the subtypes. Though an increased proportion of TBX21-subgroup cases showed a polymorphous population compared to the GATA3 subgroup with monomorphous population, no significant P-value was found. Two of the Lennert lymphomas were categorized in the GATA3 subgroup. On multivariate analysis, no significant difference was present for overall survival (P-value=0.149) and progression-free survival (P-value=0.066) amongst the IHC-defined subtypes; the trends suggest that the GATA3 subgroup has worse overall and progression-free survival.

CONCLUSIONS

The IHC-derived subtypes of GATA3 and TBX21 may have a role in prognostication and may guide further therapeutics aiding in better patient management of this aggressive group of lymphomas. The algorithm is reproducible, however some of the cases may be left unclassifiable and require further work up and gene expression profiling. The results trend toward the GATA3 subgroup having a monomorphous population with a worse overall prognosis, requiring a larger sample size for validation. The application of this algorithm in routine practice can help in risk stratification of the patients.

FUNDING

Thanks to Science-Engineering-Research-Board and AIIMS-Research section (SERB-EEQ/2016/402, AIIMS-A-653).

Chemotherapy response evaluation using diffusion weighted MRI in Ewing Sarcoma: A single center experience

BACKGROUND

Non-invasive biomarkers for early chemotherapeutic response in Ewing sarcoma family of tumors (ESFT) are useful for optimizing existing treatment protocol.

PURPOSE

To assess the role of diffusion-weighted magnetic resonance imaging (MRI) in the early evaluation of chemotherapeutic response in ESFT.

MATERIAL AND METHODS

A total of 28 patients (mean age = 17.2 ± 5.6 years) with biopsy proven ESFT were analyzed prospectively. Patients underwent MRI acquisition on a 1.5-T scanner at three time points: before starting neoadjuvant chemotherapy (baseline), after first cycle chemotherapy (early time point), and after completion of chemotherapy (last time point). RECIST 1.1 criteria was used to evaluate the response to chemotherapy and patients were categorized as responders (complete and partial response) and non-responders (stable and progressive disease). Tumor diameter, absolute apparent diffusion coefficient (ADC), and normalized ADC (nADC) values in the tumor were measured. Baseline parameters and relative percentage change of parameters after first cycle chemotherapy were assessed for early detection of chemotherapy response.

RESULTS

The responder:non-responder ratio was 21:7. At baseline, ADC ([0.864 ± 0.266 vs. 0.977 ± 0.246]) × 10^-3mm²/s; P = 0.205) and nADC ([0.740 ± 0.254 vs. 0.925 ± 0.262] × 10^-3mm²/s; P = 0.033) among responders was lower than the non-responders and predicted response to chemotherapy with AUCs of 0.6 and 0.735, respectively. At the early time point, tumor diameter (27% ± 14% vs. 4.6% ± 10%; P = 0.002) showed a higher reduction and ADC (75% ± 44% vs. 52% ± 72%; P = 0.039) and nADC (81% ± 44% vs. 48% ± 67%; P = 0.008) showed a higher increase in mean values among responders than the non-responders and identified chemotherapy response with AUC of 0.890, 0.723, and 0.756, respectively.

CONCLUSION

Baseline nADC and its change after the first cycle of chemotherapy can be used as non-invasive surrogate markers of early chemotherapeutic response in patients with ESFT.

Amphicrine Medullary Thyroid Carcinoma - a Case-Based Review Expanding on Its MUC Expression Profile

Amphicrine phenotype in medullary thyroid carcinoma (MTC) is a rare phenomenon characterized by tumor cells that show both endocrine differentiation (calcitonin secretion) and exocrine differentiation (mucin production and secretion). Not much is known about the pathobiology of amphicrine MTCs. This report undertook a case-based review approach by discussing the cytological, histopathological, and ultrastructural features of this rare enigmatic entity, expanding on the radiological and novel MUC immunohistochemistry findings from a 28-year-old MEN2B syndrome patient with C cell hyperplasia and multifocal MTC with amphicrine features. The patient had widespread hematogenous metastases at presentation. MUC immunoexpression analysis revealed evidence of micro-lumina formation, and unique to-date unreported expression patterns of MUC1, MUC5AC, and MUC6 in an amphicrine subtype of MTC. Review of the literature identified five other MTC cases with well-documented amphicrine features. Of these six cases, two were associated with MEN2B syndrome, and four had metastatic disease. Follow-up was available in three patients, and two died of disease. Recognition of this rare subtype of MTC may be of clinical interest given their frequent link to MEN2B syndrome and biological aggressiveness.

Malignancy mimics- diagnostic perplexities for oral and maxillofacial pathologists

Objective

In pathology practice, one frequently encounters benign lesions which superficially resemble malignancy clinically and histopathologically. The diagnostic pitfalls can be avoided if the approach exemplified in the present study is followed. We expect that familiarity of these cases will be helpful for pathologists at the beginning of their career.

Methods

Clinical case records of all the pathological specimens reported in our laboratory from January 2018 to September 2019 were queried. Cases displaying pseudotumor features were reviewed along with the special stains were performed and immunohistochemistry (IHC) studies. A working classification of pseudotumors presenting in the oral cavity was proposed.

Results

Immunoglobulin G4-related disease, nodular fasciitis, fibrolipoma, odontogenic keratocyst with giant cell granuloma, juvenile ossifying fibroma with central giant cell granuloma and tumor-induced osteomalacia were the most common diagnoses where the tissue specimens resembled malignancies on routine clinicoradiological evaluation and light microscopy of tissue specimens. Their differential diagnosis and the pathological diagnostic dilemmas are explained. We have also highlighted the importance of correlating clinical, radiological and microscopic details with the findings deduced from advanced pathological aids to establish the final diagnosis.

Conclusions

Pathologists should be aware of the conditions where the diagnosis of malignancy needs stricter evaluation to rule out malignant mimics. In such scenarios, correlation of light microscopy findings with clinical and radiological details cannot be overemphasized. Advanced pathological aids such as IHC, where necessary are often indispensable for reaching the accurate diagnosis in these cases.

X-linked Myopathy with Excessive Autophagy - A Rare Cause of Vacuolar Myopathy in Children

X-linked myopathy with excessive autophagy (XMEA) is a rare, recently characterized type of autophagic vacuolar myopathy caused by mutations in the VMA21 gene. It is characterized by slowly progressive weakness restricted to proximal limb muscles and generally has a favorable outcome. The characteristic histological and ultrastructural features distinguish this entity from other mimics, notably Danon disease. XMEA is an under recognized disease and should be considered in the differentials of slowly progressive myopathy in children. Awareness of this rare entity is also important for the pathologists in order to distinguish it from other causes of vacuolar myopathy in view of its favourable prognosis. We report the first genetically confirmed case of XMEA from India in an 8-year-old boy which was diagnosed based on the characteristic light microscopic and ultrastructural findings on muscle biopsy and subsequently confirmed by mutation analysis. The differential diagnostic considerations are also discussed.

Long Non-coding RNA and mRNA Co-expression Network Reveals Novel Players in Pleomorphic Xanthoastrocytoma

Histological interpretation of the rare pleomorphic xanthoastrocytoma (PXA) has been the holy grail for treatment options. However, no stand-alone clinical interventions have been developed owing to the lack of gene expression profiling data in PXA/APXA patients. We first time report the comprehensive analyses of the coding as well as long non-coding RNA (lncRNA) signatures of PXA/APXA patients. Several genes such as IGFBP2, NF1, FOS, ERBB2, and lncRNAs such as NEAT1, HOTAIRM1, and GAS5 known to play crucial roles in glioma patients were also deregulated in PXA patients suggesting the commonality in the molecular signatures. PPI network, co-expression, and lncRNA-mRNA interaction studies unraveled hub genes (such as ERBB2, FOS, RPA1) and networks that may play a critical role in PXA biology. The most enriched pathways based on gene profiles were related to TLR, chemokine, MAPK, Rb, and PI3K-Akt signaling pathways. The lncRNA targets were enriched in glucuronidation, adipogenesis, TGF-beta signaling, EGF/EGFR signaling, and cell cycle pathways. Interestingly, several mRNAs like PARVG, and ABI2 were found to be targeted by multiple lncRNAs suggesting a tight control of their levels. Some of the most prominent lncRNA-mRNA pairs were LOC728730: MRPL9, XLOC_l2_011987: ASIC2, lnc-C1QTNF5-1: RNF26. Notably, several lncRNAs such as lnc-CETP-1, lnc-XRCC3-1, lnc-RPL31-1, lnc-USP13-1, and MAPKAPK5-AS1, and genes such as RPA1, NTRK3, and CNRP1 showed strong correlation to the progression-free survival of PXA patients suggesting their potential as novel biomarkers. Overall, the findings of this study may facilitate the development of a new realm of RNA biology in PXA that may have clinical significance in the future.

EPEN-20. PDL1 expression and tumor-infiltrating immune cell subpopulations: The role of immune-checkpoint molecules in the prognosis of patients with supratentorial ependymoma and its correlation to survival

Immune checkpoint blockade of the programmed cell death ligand-1 (PD-L1)/programmed death-1 (PD-1) axis has shifted the way advanced cancers are treated. The 'ST-RELA fusion positive' and 'PF-A' molecular subgroups of ependymomas (EPN) have a dismal prognosis. AIMS: This study is undertaken to look for immunological microenvironment in ependymomas. Based on L1CAM protein expression and/or the presence of RELA/YAP1 fusion transcripts by RT-PCR, all supratentorial (ST) Grade-II/III EPNs were classified as ST-RELA, ST-YAP, and ST-not otherwise specified (NOS). Based on H3K27me3 protein expression and chromosome 1q gain, all posterior fossa (PF) EPNs were classified as PF-A or PF-B. PD-L1 (SP263, Ventana) and CD8 immunohistochemistry was performed. The enrichment of RelA protein at the PDL1 promoter site was investigated using chromatin immunoprecipitation-qPCR (ChIP-qPCR) in three ST-RELA samples. A total of 83 intracranial EPNs were included in our preliminary data, and we discovered that PD-L1 expression correlates with increasing cytotoxic T-lymphocyte infiltrates in intracranial ependymomas using PD-L1 and CD8 IHC. The majority of PD-L1-positive intracranial EPNs are members of the ST-RELA subset, which also has the highest CTL density. Our findings suggest that ST-RELA EPNs could be used in immunotherapy to target immune checkpoint modulators. To further this research, we are looking into the presence of tumour infiltrating cells such as CD3, CD8, CD163, FOXP3, and others, which can aid in characterising the tumour microenvironment in cell types expressing PD-L1.This study will also be used to predict the prognostic significance of PD-L1/PD1 and other tumour cell infiltrating biomarkers in ependymomas and correlate it with survival outcomes.

Transcriptomic profiling of nonneoplastic cortical tissues reveals epileptogenic mechanisms in dysembryoplastic neuroepithelial tumors

Low-grade dysembryoplastic neuroepithelial tumors (DNTs) are a frequent cause of drug-refractory epilepsy. Molecular mechanisms underlying seizure generation in these tumors are poorly understood. This study was conducted to identify altered genes in nonneoplastic epileptogenic cortical tissues (ECTs) resected from DNT patients during electrocorticography (ECoG)-guided surgery. RNA sequencing (RNAseq) was used to determine the differentially expressed genes (DEGs) in these high-spiking ECTs compared to non-epileptic controls. A total of 477 DEGs (180 upregulated; 297 downregulated) were observed in the ECTs compared to non-epileptic controls. Gene ontology analysis revealed enrichment of genes belonging to the following Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways: (i) glutamatergic synapse; (ii) nitrogen metabolism; (iii) transcriptional misregulation in cancer; and (iv) protein digestion and absorption. The glutamatergic synapse pathway was enriched by DEGs such as GRM4, SLC1A6, GRIN2C, GRM2, GRM5, GRIN3A, and GRIN2B. Enhanced glutamatergic activity was observed in the pyramidal neurons of ECTs, which could be attributed to altered synaptic transmission in these tissues compared to non-epileptic controls. Besides glutamatergic synapse, altered expression of other genes such as GABRB1 (synapse formation), SLIT2 (axonal growth), and PROKR2 (neuron migration) could be linked to epileptogenesis in ECTs. Also, upregulation of GABRA6 gene in ECTs could underlie benzodiazepine resistance in these patients. Neural cell-type-specific gene set enrichment analysis (GSEA) revealed transcriptome of ECTs to be predominantly contributed by microglia and neurons. This study provides first comprehensive gene expression profiling of nonneoplastic ECTs of DNT patients and identifies genes/pathways potentially linked to epileptogenesis.

Long-Term Outcomes and Safety Trends of Autologous Stem-Cell Transplantation in Non-Hodgkin Lymphoma: A Report From A Tertiary Care Center in India

Published experience with autologous stem-cell transplantation (ASCT) in non-Hodgkin lymphoma (NHL) from the Indian subcontinent is extremely limited. Here, we describe the activity and outcomes of this treatment modality at a large tertiary care center in India.

ALK-Negative Primary Cutaneous Anaplastic Large Cell Lymphoma With Systemic Involvement or Systemic ALCL With Cutaneous Lesion. A Diagnostic Dilemma

ABSTRACT

Primary cutaneous anaplastic large-cell lymphoma (C-ALCL) is a cutaneous CD30-positive lymphoproliferative disorder. The patients usually present with single or multiple cutaneous nodules or papules and about 10% cases present with extracutaneous manifestations, which are predominantly in the form of regional lymph nodal involvement. Visceral involvement especially pulmonary or hepatic involvement in C-ALCL is only rarely described in the scientific literature. Approximately 20%-42% cases show spontaneous regression, about 50% cases may recur; however, C-ALCL generally carries a good prognosis. We present a rare case of primary C-ALCL in a 66-year-old man with regional lymph nodal and hepatic involvement. Differential diagnostic entities are discussed in this report with the review of the literature.

Primary Histiocytic Sarcoma of Brain-Illustration of Two Cases with Varied Histomorphological Features

Histiocytic sarcoma (HS) is an aggressive hematolymphoid malignancy that arises from non Langerhans histiocytes and usually involves the skin, lymph nodes, and intestine. The involvement of the central nervous system (CNS) is a rare occurrence with around 30 cases being reported in English literature. Morphological and immunohistochemical evidence of histiocytic differentiation is essential for diagnosis. Prognosis is very poor and consensus on treatment is not available mainly due to its rarity. We report two cases of HS with varied clinical presentation and pathological findings and elucidate the diagnostic challenges of this rare entity.

CaSR expression in normal parathyroid and PHPT: new insights into pathogenesis from an autopsy-based study

PURPOSE

Calcium sensing receptor (CaSR), on the surface of normal parathyroid cells, is essential for maintaining serum calcium levels. The normal pattern of CaSR immunostaining remains undefined and is presumptively circumferential. Given the physiological variation in serum calcium, we postulated that CaSR expression could not be uniformly circumferential. Also, cytoplasmic expression has not been evaluated either in normal or pathological tissues. We studied normal parathyroid tissues derived from forensic autopsies and those rimming parathyroid adenomas for membranous and cytoplasmic CaSR immunoexpression. Results were compared with primary hyperparathyroidism (PHPT) to look for any pathogenetic implications.

MATERIALS AND METHODS

We evaluated 34 normal parathyroid tissues from 11 autopsies, 30 normal rims, 45 parathyroid adenoma, 10 hyperplasia, and 7 carcinoma cases. Membranous expression was categorized complete/incomplete and weak/moderate/strong; scored using Her2/Neu and Histo-scores; predominant pattern noted. Cytoplasmic expression was categorized negative/weak/moderate/strong; predominant intensity noted.

RESULTS

Normal autopsy-derived parathyroid tissues were Her2/Neu 3 + , but incomplete membranous staining predominated in 85%. Their immune-scores were significantly more than the cases (p <  < 0.05). The mean histo-score of normal rims was intermediate between the two (p <  < 0.05). Cytoplasmic expression was strong in all autopsy-derived tissues, weak/negative in hyperplasia (100%), moderate in 16% adenomas, and 43% carcinomas.

CONCLUSIONS

Normal autopsy-derived parathyroid tissues showed strong but predominantly incomplete membranous expression. Surface CaSR expression decreased in PHPT and is probably an early event in parathyroid adenoma, seen even in normal rims. Whether there is a defect in CaSR trafficking from the cytoplasm to the cell surface in adenoma and carcinoma needs further evaluation.

Atrophic Kidney Like Lesion: A Provisional Entity With Brief Review of Literature

Atrophic kidney-like lesion (AKLL) is a provisional renal entity with distinct morphological and immunohistochemical features. It characteristically resembles thyroid-like follicular renal cell carcinoma (RCC) of kidney, an emerging renal entity. Very few patients of AKLL have been reported in the literature. We are hereby describing the clinicopathological features of AKLL in a 38-year-old man. The patient was incidentally found to have a renal mass and underwent radical nephrectomy. The morphological and immunohistochemical findings revealed features of AKLL. The patient on 24 months' post-operative period follow-up is alive without recurrence or metastasis.

Is There Any Relationship Between Systemic Inflammatory Markers And Meningioma Grade?

BACKGROUND

Systemic inflammatory markers have been found to be of value in predicting the prognosis in renal cell and gastrointestinal cancers. Recent studies in gliomas correlating with Systemic inflammatory markers (SIMS) have shown promise in predicting survival.

OBJECTIVE

Meningiomas are the commonest intracranial primary brain tumors in adults. There is a need to distinguish low and high grade meningiomas preoperatively as they have crucial implications for the radicality of surgical excision and prognostication.

METHODS

A retrospective search was conducted, and the newly diagnosed meningioma cases were studied. The preoperative hematological parameters of the patients and pathological tumor grades were noted. The grade 1 meningioma was defined as low-grade meningioma while grade 2 and 3 meningiomas were defined as high-grade meningioma. Statistical analysis was performed to determine the association between the hematological parameters and tumor grade.

RESULTS

Seven hundred and eighty meningioma cases with a mean age of 43.5 years were included. The ANC, NLR, and dNLR were found to be significantly elevated in high-grade meningioma (P = 0.03). Other inflammatory parameters including TLC failed to show a statistically significant difference when compared between the grades of meningioma. ROC analysis further showed limited value of these markers in predicting meningioma grade. However, an elevated ANC (OR = 1.08, 95% CI = 1.02-1.14), male sex (OR = 1.71, 95% CI = 1.13-2.58), and tumor origin from sites other than the skull base or thecal sac (OR = 3.33, 95% CI = 1.93-6.12) were predictive of high-grade meningioma in regression analysis.

CONCLUSION

Preoperative hematological inflammatory parameters have limited value in predicting the grade of tumor in meningiomas. An elevated preoperative ANC, NLR, and dNLR were found to be more frequently associated with high grade of meningiomas.