Seronegative pachymeningitis.

Background: Surgical pathology specimens from patients with hypertrophic pachymeningitis are infrequently encountered. After excluding infectious and neoplastic causes, autoimmune conditions should be considered, especially neurosarcoidosis, rheumatoid arthritis, granulomatosis with polyangiitis (GPA), and IgG4-related disease (IgG4-RD) before the case is designated "idiopathic". However, even if histological findings strongly favor one of these conditions, clinical and serological correlation is mandatory.

Isocitrate dehydrogenase-mutant astrocytoma in persons aged 55 years and older: Survival differences versus the young.

Isocitrate dehydrogenase (IDH)-mutant astrocytomas show a peak incidence in young and middle-aged adults and have relatively favorable outcomes. In patients with these tumors ≥55 years at diagnosis, clinical, histopathologic, and prognostic characteristics are less clear. Here, we compared histopathological, immunohistochemical, molecular, and overall survival of 34 patients aged ≥55 years with a group of 84 patients aged 19-54 years; all had IDH mutant astrocytomas.

Clinical and molecular assessment of cystic sellar salivary gland-like lesions.

Background: Symptomatic sellar salivary gland-like lesions (SSGLs) are uncommon, with fewer than two dozen case reports. Prior case reports have also not detailed pre- or postoperative endocrinopathies to determine if these lesions can be clinically distinguished prior to biopsy from Rathke cleft cysts (RCCs). In addition, prior molecular testing was attempted to provide further insights as to whether these might be developmental lesions or true neoplasms, but testing was unsuccessful.

Concurrent ependymal and ganglionic differentiation in a subset of supratentorial neuroepithelial tumors with EWSR1-PLAGL1 rearrangement.

Neuroepithelial tumors with fusion of PLAGL1 or amplification of PLAGL1/PLAGL2 have recently been described often with ependymoma-like or embryonal histology respectively. To further evaluate emerging entities with PLAG-family genetic alterations, the histologic, molecular, clinical, and imaging features are described for 8 clinical cases encountered at St. Jude (EWSR1-PLAGL1 fusion n = 6; PLAGL1 amplification n = 1; PLAGL2 amplification n = 1).

Mixed pituitary adenoma/pituitary neuroendocrine tumor-gangliocytoma: Immunohistochemical insights.

Mixed pituitary adenoma/PitNET-gangliocytomas (PA/PitNET-GC) have been reported in small series over the past 20 years; some had limited immunohistochemistry (IHC) data. We interrogated our experience over 20 years, focusing on patterns of the GC component and IHC results for anterior pituitary hormones, transcription factors, NFP, and CAM5.2.

Histological and neuroimaging comparison of SMART syndrome versus focal neuronal gigantism.

Two of the rarest radiation-induced adverse effects are focal neuronal gigantism (FNG) and SMART syndrome (stroke-like migraine attacks after radiation therapy). Both conditions develop years, and sometimes decades, after receipt of therapeutic radiation to the brain. To date, there are only 3 previously reported cases of FNG, all of which describe cortical thickening, enlarged "hypertrophic" neurons, and neuronal cytological changes.

Some CNS sarcomas seen: A 22-year series.

Aims: Central nervous system (CNS) and spine are seldom impacted by primary or metastatic sarcomas. We reviewed our 22-year experience with metastatic versus primary mesenchymal sarcomas in adults versus pediatric patients, additionally asking how many might today undergo nomenclature changes using CNS World Health Organization, 5 edition criteria.

Materials And Methods: Case identification via text word search of pathology databases from our adult and pediatric referral hospitals, 2000 to August 2022, with exclusion of peripheral nervous system and primary chondro-osseous and notochordal tumors.

Leptomeningeal metastases and dural spread in adult high-grade astrocytomas.

Leptomeningeal (LM) metastases or dural spread by adult high-grade astrocytomas are problematic; it is unclear which tumor types are predisposed to spread and at what time intervals from original diagnosis. We reviewed our recent experience with these tumor types with LM or dural spread, all of which had assessments that allowed CNS World Health Organization, 5th Edition classification. Following a database search, 2018-present, 10 patients were identified: 4 glioblastomas, IDH-wildtype, WHO grade 4; 4 astrocytomas, IDH-mutant, WHO grade 4; 1 high-grade astrocytoma with piloid features (HGAP) proven by DNA methylation, and 1 high-grade astrocytic tumor that fell closest to the HGAP category by DNA methylation.

Childhood Small-Vessel Primary Angiitis of the Central Nervous System: Overlap With MOG-Associated Disease.

Background: Childhood (c) primary angiitis of the central nervous system (PACNS) is a rare condition that most often affects small vessels (SV), is nearly exclusively lymphocytic, and devoid of vessel necrosis. Diagnosis of cSV-PACNS is challenging. We noted possible histological overlap of cSV-PACNS with myelin oligodendrocyte glycoprotein disease (MOGAD) on biopsy, prompting a 10-year retrospective review of our experience.

Cerebral amyloidomas: Perspective on unusual morphological features.

Aims: Cerebral amyloidomas (CAs) are mass-producing congophilic lesions most commonly due to λ light chain deposits, contrasting them with light chain deposition disease (LCDD) which has non-polarizable, often κ light chain deposition.

Materials And Methods: Although usual histological features are well known, we detail 3 recent CAs with unusual morphological findings and review the literature specifically for these features.

Results: Two women, aged 56 and 58 years, had right cerebral white matter CAs.

Intracranial mesenchymal tumors with FET-CREB fusion are composed of at least two epigenetic subgroups distinct from meningioma and extracranial sarcomas.

'Intracranial mesenchymal tumor, FET-CREB fusion-positive' occurs primarily in children and young adults and has previously been termed intracranial angiomatoid fibrous histiocytoma (AFH) or intracranial myxoid mesenchymal tumor (IMMT). Here we performed genome-wide DNA methylation array profiling of 20 primary intracranial mesenchymal tumors with FET-CREB fusion to further study their ontology. These tumors resolved into two distinct epigenetic subgroups that were both divergent from all other analyzed intracranial neoplasms and soft tissue sarcomas, including meningioma, clear cell sarcoma of soft tissue (CCS), and AFH of extracranial soft tissue.

Intracranial mesenchymal tumor with FET-CREB fusion-A unifying diagnosis for the spectrum of intracranial myxoid mesenchymal tumors and angiomatoid fibrous histiocytoma-like neoplasms.

Intracranial mesenchymal tumors with FET-CREB fusions are a recently described group of neoplasms in children and young adults characterized by fusion of a FET family gene (usually EWSR1, but rarely FUS) to a CREB family transcription factor (ATF1, CREB1, or CREM), and have been variously termed intracranial angiomatoid fibrous histiocytoma or intracranial myxoid mesenchymal tumor. The clinical outcomes, histologic features, and genomic landscape are not well defined. Here, we studied 20 patients with intracranial mesenchymal tumors proven to harbor FET-CREB fusion by next-generation sequencing (NGS).

Comprehensive analysis of diverse low-grade neuroepithelial tumors with FGFR1 alterations reveals a distinct molecular signature of rosette-forming glioneuronal tumor.

The FGFR1 gene encoding fibroblast growth factor receptor 1 has emerged as a frequently altered oncogene in the pathogenesis of multiple low-grade neuroepithelial tumor (LGNET) subtypes including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor (DNT), rosette-forming glioneuronal tumor (RGNT), and extraventricular neurocytoma (EVN). These activating FGFR1 alterations in LGNET can include tandem duplication of the exons encoding the intracellular tyrosine kinase domain, in-frame gene fusions most often with TACC1 as the partner, or hotspot missense mutations within the tyrosine kinase domain (either at p.N546 or p.

Morphological diversity in H3G34-mutant high-grade gliomas: Ganglionic and epithelioid features.

Although increasing numbers of central nervous system (CNS) tumors with stereotypic morphological, molecular, and/or site-specific features have been recently reported, morphological diversity is often recognized within a tumor category as more cases are encountered. Such was the case with diffuse midline gliomas, H3K27M-mutant. Therefore, it is not surprising that two cases of H3G34-mutant.

Reliability of fluorescein-assisted stereotactic brain biopsies in predicting conclusive tissue diagnosis.

Background: The purpose of this study was to assess the reliability of fluorescein sodium in predicting conclusive tissue diagnosis in stereotactic brain biopsies and to characterize features of contrast-enhancing and non-enhancing MRI lesions associated with fluorescence.

Methods: A total of 19 patients were studied, 14 of which had contrast-enhancing and 5 of which had non-enhancing lesions on preoperative T1 post-gadolinium MRI scan. All patients received 3 mg/kg fluorescein sodium during anesthesia induction.

How frequent is double pathology in Rasmussen encephalitis?

Rasmussen encephalitis (RE) is an uncommon, medically refractory cause of seizures that usually presents in childhood or adolescence resulting in unilateral hemispheric atrophy in most cases. The purported immune-mediated cause of the disease is supported by the characteristic histopathologic features of diffuse perivascular and intraparenchymal T-cell-predominant infiltrates, microglial activation with microglial nodules, and neuronophagia. A small number of reports have emerged, however, suggesting that double pathology (such as focal cortical dysplasia (FCD) or hippocampal sclerosis) may be present.

Cystic sellar salivary gland-like lesions.

Introduction: Cystic sellar salivary gland-like lesions (CSSLs) are exceedingly rare, with fewer than a dozen case reports. They contain amorphous colloid identical to Rathke cleft cyst contents, but the cyst wall additionally shows cohesive aggregates of benign salivary glands. We report three new examples.

Clinicopathologic and molecular features of intracranial desmoplastic small round cell tumors.

Desmoplastic small round cell tumors (DSRCTs) are highly aggressive sarcomas that most commonly occur intra-abdominally, and are defined by EWSR1-WT1 gene fusion. Intracranial DSRCTs are exceptionally rare with only seven previously reported fusion-positive cases. Herein, we evaluate the clinical, morphologic, immunohistochemical and molecular features of five additional examples.

Pituitary Adenomas in Transgender Individuals?

Transgender individuals may receive long-term hormonal treatment as part of their sexual transition; limited literature has suggested that they consequently may be predisposed to development of prolactinomas. We questioned whether we had encountered such cases. Pathology databases were searched for the years 2000-2019 for tissue specimens from transgender individuals; Sixty surgical specimens from 58 individuals and 8 cytology specimens were identified.