Khalid Altuhaini

Bio: Khalid Altuhaini is an academic researcher. The author has contributed to research in topics: Medicine & Radiology. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Fetal Ventriculomegaly: A Review of Literature

Abstract: Fetal ventriculomegaly refers to ventricular enlargement that is diagnosed prenatally. It is one of the most common fetal anomalies. The diagnosis is made by ultrasound when the arterial diameter of the ventricle is more than 10 mm. Once it is diagnosed, further evaluation by detailed ultrasound, fetal MRI, and genetic studies is required. Prenatal surgical management of fetal ventriculomegaly is still limited and associated with high risks. Postnatal management is similar to the treatment of other types of hydrocephalus. Fetal ventriculomegaly is a heterogeneous condition with various etiologies and a wide spectrum of neurodevelopmental outcomes. The outcomes depend mainly on the severity of ventriculomegaly and associated structural abnormalities. This article aims to review the literature about various aspects of fetal ventriculomegaly.

Thalamic Tumors in a Pediatric Population: Surgical Outcomes and Utilization of High-Definition Fiber Tractography and the Fiber Tracking Technique

Abstract: Objective: This study aimed to assess the operability of thalamic tumors since they are generally considered to be inoperable and to have poor outcomes. Advancements in neuroimaging, neuronavigational technology, and intraoperative neurophysiological monitoring allow accurate planning and safe resection. Methods: Clinical data and reports of 10 pediatric patients with thalamic tumors were retrieved retrospectively. All 10 patients underwent surgical intervention. Diffusion tensor tractography (DTI) was used preoperatively to select the safest surgical route. Intraoperative MRI and postoperative MRI were used to evaluate the extent of resection. Results: There were three gross total resections (GTRs), two subtotal resections (STRs), two partial resections (PRs), and three biopsies. All patients had unilateral thalamic tumors. Different surgical approaches were used according to the relationship with the internal capsule and corticospinal tract and according to the preoperative DTI. Five patients had pilocytic astrocytoma, two had diffuse pediatric-type high-grade glioma, one had ganglioglioma, one had pediatric-type diffuse low-grade glioma, and one had atypical teratoid rhabdoid tumor (ATRT). The outcomes of low-grade tumors were favorable, especially for those who underwent resection, and those of high-grade tumors were poor regardless of the extent of resection. Conclusion: Our review shows that surgical resection of thalamic tumors can be done safely and offers favorable outcomes for patients with low-grade tumors, even without adjuvant therapy. Our study provides further evidence for thalamic tumors operability and safe resection.

An integrative histopathological and epigenetic characterization of primary intracranial mesenchymal tumors, FET:CREB-fused broadening the spectrum of tumor entities in comparison with their soft tissue counterparts.

Abstract: FET:CREB fusions have been described in a variety of tumors from various phenotypes. Recently, these fusion transcripts were reported in intracranial tumors, variably named intracranial mesenchymal myxoid tumors or angiomatoid fibrous histiocytomas. Controversy remains concerning the terminology for these tumors. Here, we report 11 cases of central nervous system mesenchymal tumors with proven FET:CREB fusion. Most DNA methylation profiles were not classifiable using the Heidelberg Brain Tumor or Sarcoma Classifier (v11b4/v12.2). However, by using unsupervised t-SNE and hierarchical clustering analyses, six of the cases constituted a distinct cluster. The remaining four tumors showed no obvious relation to any of the other referenced classes but were close to the clusters of extra-CNS angiomatoid fibrous histiocytomas (n = 1), clear cell sarcomas (n = 1), or solitary fibrous tumors (n = 2). Our findings confirm that intracranial FET:CREB-fused tumors do not represent a single molecular tumor entity, although most samples clustered close to each other, indicating the existence of a distinct epigenetic group that could potentially be partially masked by the low number of cases included. Further analyses are needed to characterize intracranial FET:CREB fused-defined tumors in more detail.

A novel SMARCA2-CREM fusion: expanding the molecular spectrum of intracranial mesenchymal tumors beyond the FET genes.

Abstract: A novel histomolecular tumor of the central nervous system, the "intracranial mesenchymal tumor (IMT), FET-CREB fusion-positive" has recently been identified in the literature and will be added to the 2021 World Health Organization Classification of Tumors of the Central Nervous System. However, our latest study using DNA-methylation analyses has revealed that intracranial FET-CREB fused tumors do not represent a single molecular tumor entity. Among them, the main subgroup presented classical features of angiomatoid fibrous histiocytoma, having ultrastructural features of arachnoidal cells, for. Another tumor type with clear cell component and histopathological signs of aggressivity clustered in close vicinity with clear cell sarcoma of soft tissue. Herein, we report one case of IMT with a novel SMARCA2-CREM fusion which has until now never been described in soft tissue or the central nervous system. We compare its clinical, histopathological, immunophenotypic, genetic and epigenetic features with those previously described in IMT, FET-CREB fusion-positive. Interestingly, the current case did not cluster with IMT, FET-CREB fusion-positive but rather presented histopathological (clear cell morphology with signs of malignancy), clinical (with a dismal course with several recurrences, metastases and finally the patient's death), genetic (fusion implicating the CREM gene), and epigenetic (DNA-methylation profiling) similarities with our previously reported clear cell sarcoma-like tumor of the central nervous system. Our results added data suggesting that different clinical and histomolecular tumor subtypes or grades seem to be included within the terminology "IMT, FET-CREB fusion-positive", and that further series of cases are needed to better characterize them.

Mesenchymal non-meningothelial tumors of the central nervous system: a literature review and diagnostic update of novelties and emerging entities

Abstract: The fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System (CNS) now includes mesenchymal tumors that occur uniquely or frequently in the CNS. Moreover, this version has aligned the terminology of mesenchymal tumors with their soft tissue counterparts. New tumor types have been added, such as the "intracranial mesenchymal tumor, FET-CREB fusion-positive", the "CIC-rearranged sarcoma", and the "Primary intracranial sarcoma, DICER1-mutant". Other entities (such as rhabdomyosarcoma) have remained in the current WHO classification because these tumor types may present specificities in the CNS as compared to their soft tissue counterparts. Based on an extensive literature review, herein, we will discuss these newly recognized entities in terms of clinical observation, radiology, histopathology, genetics and outcome, and consider strategies for an accurate diagnosis. In light of this literature analysis, we will also introduce some potentially novel tumor types.

Angiomatoid Fibrous Histiocytoma: Case Presentation with Review of Literature

Abstract: Angiomatoid fibrous histiocytoma is a rare neoplasm with an intermediate malignant potential, that mostly occurs in the subcutis and features varying proportions of epithelioid, ovoid and spindle cells in a nodular and syncytial growth pattern, with hemorrhagic pseudovascular spaces. Here, we report the clinical case of a 68-year-old man who presented with AFH on the right arm; the disease relapsed a few years after surgical excision. We also conduct a brief review of the literature, focusing on the biological and genetic characteristics and the differential diagnosis from other more or less similar entities.

De novo 3q13.13q21.2 interstitial deletion and paternal 12p13.3 microdeletion in a fetus with dysplasia of the corpus callosum and ventriculomegaly: A case report

Abstract: Chromosome 3q syndrome is a well-known genetic condition caused by interstitial deletion in the long arm of chromosome 3. The phenotype of this syndrome is variable and the great variability in the extent of these deletions leads to a wide spectrum of clinical manifestations. Terminal 12p deletion represents one of the rarest subtelomeric imbalances; patients with distal monosomy 12p present different phenotypes ranging from muscular hypotonia to autism spectrum disorders. The present study reported a prenatal diagnosis of a male fetus presenting ultrasound evidence of corpus callosum dysplasia and ventriculomegaly showing a 3q13q21.2 deletion and a 12p13.33 microdeletion paternally inherited. Among several features previously attributed to the terminal deletion of 3q, corpus callosum dysplasia and ventriculomegaly have rarely been reported together. As the 12p13.33 microdeletion in the father was associated only with muscular hypotonia and joint laxity, the involvement of terminal 12p deletions in the clinical features of the fetus was not possible to verify during the prenatal period. The present case report may provide a reference for prenatal diagnosis and genetic counseling in patients who present 3q13q21.2 deletions and 12p13.33 microdeletion.