A compact printed antenna with three rejected bands has been examined and presented in this manuscript. This antenna is fed by a coplanar waveguide and operates over a wide range of frequencies. An ...arc-shaped, rectangular strip like and split-ring slot have been etched from the designed radiating patch to generate the rejection peaks at Wi-MAX, WLAN and X-band satellite communication. Primarily, the rectangular patch has been considered and further this patch is modified to acquire the UWB frequency spectrum from 3.1 to 10.6 GHz. The overall size of designed antenna is 27 × 27 × 1.6 mm
3
which comprises of novel structure of radiating patch and 50Ω CPW feed. After modification the final geometry of radiating patch, proposed antenna divulges the VSWR bandwidth of 11.88 GHz (2.12–14.0 GHz). Further, by introducing different types of slots in the final structure of radiating patch antenna exhibits Wi-MAX (3.16–3.76 GHz), WLAN (5.26–5.87 GHz) and X-band satellite communication (7.30–7.68 GHz) rejected bands. Furthermore, designed UWB antenna embellishes the gain of −7.64 dBi, −4.80 dBi and −4.92 dBi at rejected bands, whereas, the gain of antenna at other frequencies varies between 3.65 and 8.19 dBi. Proposed UWB antenna exemplifies the radiation efficiency variation in 77–98% except notched frequency bands. The radiation pattern and group delay of antenna is also at the acceptable level for existing UWB applications. Lastly, final optimized geometry of antenna with three band notched characteristics is being fabricated and verified for the validation of simulated results. Both the results are related and are found in good agreement with each other and also divulged that proposed antenna is eligible candidate for UWB applications with band rejection characteristics.
Despite significant advances in the understanding of the biology, the prognosis of glioblastoma (GBM) remains dismal. The objective was to carry out whole-exome sequencing (WES) of Indian glioma and ...integrate with that of TCGA to find clinically relevant mutated pathways.
WES of different astrocytoma samples (
= 42; Indian cohort) was carried out and compared with that of TCGA cohort. An integrated analysis of mutated genes from Indian and TCGA cohorts was carried out to identify survival association of pathways with genetic alterations. Patient-derived glioma stem-like cells, glioma cell lines, and mouse xenograft models were used for functional characterization of calcitonin receptor (CALCR) and establish it as a therapeutic target.
A similar mutation spectrum between the Indian cohort and TCGA cohort was demonstrated. An integrated analysis identified GBMs with defective "neuroactive ligand-receptor interaction" pathway (
= 23; 9.54%) that have significantly poor prognosis (
< 0.0001). Furthermore, GBMs with mutated calcitonin receptor (
) or reduced transcript levels predicted poor prognosis. Exogenously added calcitonin (CT) inhibited various properties of glioma cells and pro-oncogenic signaling pathways in a CALCR-dependent manner. Patient-derived mutations in CALCR abolished these functions with the degree of loss of function negatively correlating with patient survival. WT CALCR, but not the mutant versions, inhibited Ras-mediated transformation of immortalized astrocytes
Furthermore, calcitonin inhibited patient-derived neurosphere growth and
glioma tumor growth in a mouse model.
We demonstrate CT-CALCR signaling axis is an important tumor suppressor pathway in glioma and establish CALCR as a novel therapeutic target for GBM.
.
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.
Purpose
H3K27M mutant diffuse midline gliomas (DMGs) are considered grade IV irrespective of histological features and have dismal prognosis. We evaluated clinico-pathologic, radiological, and ...molecular characteristics of DMGs across all ages.
Methods
One twenty-six DMGs were identified over 10 years. Immunohistochemistry was done for H3K27M, ATRX, IDH1, and p53, and Sanger sequencing performed for IDH1 and H3K27M mutation. Patient demographics and clinico-radiologic characteristics were reviewed and survival analysis performed.
Results
DMGs comprised 5.3% of all gliomas with 49.2% H3K27M mutant and 50.8% wild types. Majority (75.68%) of pediatric and 38.20% of adults were H3K27M mutant (
p
= 0.0001). Amongst H3K27M mutants, brainstem (46.43%) was the commonest location in pediatric and thalamus (61.76%) in adults. H3K27M mutation was mutually exclusive with IDH mutation in 93.55%, while p53, ATRX mutation were seen in 56.4% and 30.6% cases respectively. Software-based immunohistochemistry evaluation (H-scoring) showed 99.2% concordance with sequencing for H3K27M mutation. Radiologically, no significant difference in contrast enhancement was seen between mutant and wild types (
p
= 0.05). The difference in overall survival (OS) was not significant in mutant versus wild types, with age or location. Tumor resection independently and on correlation with H3K27M did not influence OS (
p
= 0.51 and
p
= 0.47). Adjuvant therapy impacted survival significantly in adults (
p
= 0.0009), however, not in pediatric cases (
p
= 0.06).
Conclusions
The study highlights the differences in frequency and location of pediatric and adult DMGs. IHC (H-scoring) for H3K27M mutation is an excellent surrogate for sequencing. Prognosis remains dismal irrespective of age, location, and H3K27M status. Potential therapeutic targets need to be explored.
Diffuse midline gliomas (DMGs) are rare and devastating tumors with limited therapeutic options. Programmed death‐ligand 1 (PD‐L1) expression represents a potential predictive biomarker for ...immunotherapy. One hundred and twenty‐six DMGs (89 adult and 37 pediatric) were assessed for immune profile (PD‐L1, cluster of differentiation (CD3, CD8) and genetic markers (mutation in 27th amino acid of histone H3 (H3K27M), alpha thalassemia/mental retardation syndrome X‐linked (ATRX), isocitrate dehydrogenase 1 (IDH1), p53) by immunohistochemistry. Sanger sequencing was done for IDH1 and H3K27M. The thalamus was the commonest site. Four molecular subgroups of DMGs were identified. H3K27M mutation was more frequent in children (P = 0.0001). The difference in median overall survival (OS) was not significant in any of the four molecular subgroups (P > 0.05). PD‐L1 expression was significantly higher in H3K27M/IDH1 double‐negative adult glioblastomas (GBMs) (P = 0.002). Strong PD‐L1 expression was more frequent in grade IV tumors and thalamic location, although the difference was not significant (P = 0.14 and P = 0.19 respectively). Positive PD‐L1 expression was significantly associated with high tumor‐infiltrating lymphocytes count (P < 0.05). There was no significant difference in median OS in PD‐L1‐positive versus negative cases among four genetic subgroups (P > 0.05). On univariate analysis, there was no direct correlation of PD‐L1 with any genetic alteration, except H3K27M mutation (P = 0.01). CD3 infiltration was similar in both adults and pediatric ages (84.3% and 78.4%, respectively) while CD8 expression was significantly greater in adults compared to children (74.1% vs 37.8%, P = 0.0001). This is the first comprehensive analysis highlighting molecular and immune profiles of DMGs. Despite molecular and clinicopathological diversity, overall survival in DMGs remains dismal. Multicentric studies with larger numbers of cases should be undertaken for stratifying DMGs according to their age, immune and molecular profiles, to develop effective immunotherapies.
Introduction: Uterine tumors resembling ovarian sex cord tumor (UTROSCT) are a unique group of neoplasms with diverse morphology and immunophenotypic characteristics, coexpressing sex cord, ...epithelial, and smooth-muscle markers. To date, less than 100 cases have been reported and there is paucity of data concerning their clinical behavior. Materials and Methods: All cases of uterine body tumors diagnosed over a period of two and a half years (2016-2018) were retrieved. Histopathological features were reviewed and extended panel of immunohistochemistry was performed to identify cases of UTROSCTs. Results: Six cases of UTROSCTs were identified with a median age of 46.5 years. Four of them presented with menorrhagia, while two with postmenopausal bleeding including one with a history of carcinoma breast. Three of these cases were initially misdiagnosed as endometrial stromal sarcoma and adenocarcinomas. They all underwent hysterectomy with bilateral salpingo-oophorectomy. Conclusion: It is considered a tumor with low malignant potential; however, one out of six cases (16.7%) in our study showed metastasis, within 1 year of diagnosis. It is important to recognize this entity as it mimics a wide range of both benign and malignant tumors. Molecular pathogenesis and exact management protocols remain elusive due to rarity,hence, multi-institutional studies are warranted.
Adenoid cystic carcinoma (AdCC) is a malignant epithelial neoplasm that occurs rarely in the lower respiratory tract (LRT). AdCC at various sites is associated with the novel fusion transcript ...MYB-NFIB, along with the overexpression of the Myb protein. The expression of the Myb protein in AdCC of the LRT has not been evaluated much.
Cases of AdCC of the LRT diagnosed on cytology or histology were retrieved from our institutional archives. c-Myb expression was analyzed on immunocytochemistry/immunohistochemistry (ICC/IHC) and was correlated with clinicopathological parameters.
Twenty-three samples of AdCC originating from the LRT were included in the study. Four cases were diagnosed on cytology, 3 of which had corresponding histology specimens. The remaining 19 cases had either biopsy or resection. Most of the patients presented with endobronchial mass. The mean age was 49.4 years and a male predominance was seen. ICC and IHC for c-Myb showed positivity in 75 and 59% of the cases, respectively. Western blot was used to validate IHC results.
AdCC of the LRT is rare and hence poses diagnostic difficulty. Cytology smears can be utilized for c-Myb ICC. The presence of c-Myb immunopositivity in most cases may possibly make Myb a diagnostic biomarker and a therapeutic target for personalized treatment.
Intracranial lipomas are rare developmental lesions, predominantly occurring in the interhemispheric location. Osteochondrolipoma is an extremely rare variant of lipoma with osseous and chondroid ...differentiation. We present a case of interhemispheric osteochondrolipoma, in a 2.5‐years‐old male child which was detected antenatally, in association with corpus callosum agenesis. The lesion progressively increased in size with resulting compression of surrounding structures, and was subjected to microsurgical decompression. To the best of our knowledge, this is the first case of intracranial interhemispheric osteochondrolipoma in the existing medical literature. Peculiarities of this case and the diagnostic and surgical challenges are discussed.
Neuroblastoma‐like schwannoma is an extremely rare histological variant of schwannoma, which histologically mimics a malignant small round cell tumor. Only 19 cases have been reported in the ...literature to date. We report a case of this tumor located at the skull base in a 44‐year‐old woman who presented with symptoms of right‐sided earache and hearing loss. MRI revealed a large, lobulated, extra‐axial mass measuring 8.8 cm × 3.6 cm × 4.2 cm in the floor of the middle and posterior cranial fossa. Microscopic examination revealed a perplexing histopathology with peculiar collagenous rosettes. Differential diagnoses included a broad range of benign and malignant tumors. Typical schwannoma seldom poses a difficulty in diagnosis; however, this unusual variant is a diagnostic challenge which requires an extensive clinico‐radiological correlation and immunohistochemical work‐up. Hence, knowledge of this entity is a must to avoid erroneous diagnosis and inappropriate treatment.
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