High-grade astrocytoma with piloid features (HGAP) is a novel condition introduced in the 2021 World Health Organization classification. Given that it has been recently classified, reports clarifying Show more
High-grade astrocytoma with piloid features (HGAP) is a novel condition introduced in the 2021 World Health Organization classification. Given that it has been recently classified, reports clarifying its clinical features or diagnostic criteria are lacking, especially in cases of atypical presentation. Herein, the authors present a rare case of HGAP with repeated symptomatic hemorrhages. A woman in her 20s presented with an acute headache and vertigo. Computed tomography and magnetic resonance imaging revealed a 2.5 × 2.8 × 2.3-cm hemorrhagic cerebellar mass with calcifications. After moderate improvement of her symptoms, she developed recurrent hemorrhage, and the tumor size increased (3.0 × 3.6 × 4.0 cm) 18 days later, necessitating resection. Pathological and molecular analyses confirmed the diagnosis of HGAP with an FGFR1-TACC1 fusion, MTAP/CDKN2A/B deletion, and SETD2 rearrangement. Radiologically, the presence of calcification and cystic components and the absence of perilesional edema were atypical features of previously reported HGAP. Although recurrent symptomatic intracranial hemorrhages are rare in HGAP, enhancing lesions on magnetic resonance imaging suggest the need for resection to obtain tissue for molecular diagnosis and guide adjuvant treatment strategies. https://thejns.org/doi/10.3171/CASE24395. Show less
The liver X receptors (LXR-alpha and -beta) are nuclear oxysterol receptors that play pivotal roles in regulating the expression of genes involved in cholesterol transport and metabolism. Recently, se Show more
The liver X receptors (LXR-alpha and -beta) are nuclear oxysterol receptors that play pivotal roles in regulating the expression of genes involved in cholesterol transport and metabolism. Recently, several groups have reported that the LXRs also regulate adrenal steroidogenesis. However, the roles of LXRs in the hypothalami-pituitary-adrenal axis, especially whether they regulate proopiomelanocortin (POMC) gene expression in the pituitary, remain to be elucidated. In this report, we demonstrate that LXR mRNA is expressed in the pituitary and that at the protein level, LXR-alpha is dominantly expressed. Next, we show that the LXR agonist TO901317 (TO) increased POMC mRNA levels and the number of cells immunostained with anti-ACTH antibody in the mouse pituitary. We also confirmed that TO elevated plasma ACTH and serum corticosterone levels in vivo and increased the total tissue content of immunoreactive ACTH in the pituitary. TO activated the rat POMC gene promoter (-706/+64 bp) in GH3 and AtT-20 cells. Silencing of LXR-alpha mRNA expression in GH3 cells with small interfering RNA specific to LXR-alpha caused a loss of promoter activity induced by the LXR ligand, suggesting that LXR-alpha directly regulates the POMC gene promoter. EMSAs also demonstrated that the retinoid X receptor-alpha/LXR-alpha heterodimer bound to the region between -73 and -52 bp in the rat POMC gene promoter, and this site was responsible for the induction by TO, as confirmed by chromatin immunoprecipitation assays using AtT-20 cells. Our findings provide the first evidence that LXR-alpha positively regulates the POMC gene promoter at the transcriptional level and suggest LXR-alpha to be a coordinator for cross talk between lipid metabolism and neuroendocrinology. Show less