Search

Although frozen section pathology (FSP) is commonly performed during surgery for glioma-suspicious lesions, confounders of accuracy are largely unknown. FSP and final diagnosis were compared in 398 surgeries for glioma-suspicious lesions. Diagnostic accuracy, risk factors for diagnostic shift from neoplastic to non-neoplastic tissue and vice versa according to the final diagnosis, and the impact on intraoperative and postoperative decision-making were analyzed. Diagnostic shift occurred in 70 cases (18%), and sensitivity, specificity, and the positive (PPV) and negative (NPV) predictive value of FSP were 82.5%, 77.8%, 99.4%, and 9.3%, respectively. No correlations between shift and patients' age and sex, sample fluorescence or volume, tumor location, correct information on the pathology form, final high- or low-grade histology, or molecular alterations were found (p >.05, each). Shift was more common after irradiation (25% vs 15%; p =.025) or chemotherapy (26% vs 15%; p =.022) than in treatment naïve cases and correlated with the type of surgery (p =.002). FSP altered intraoperative decision-making in 25 cases (6%). Postoperative shift led to repeated surgery in 12 patients (3%). In 45 cases, in which FSP and final diagnosis based on the same tissue, shift occurred in only 5 patients (11%), and sensitivity, specificity, PPV, and NPV for FSP were 77.4%, 78.6%, 88.9%, and 61.1%, respectively. No correlations between diagnostic shift and any of the analyzed variables were found (p >.05, each). Although accuracy of FSP during glioma surgery is sufficient, moderate NPV should be considered during intraoperative decision-making. While confounders are sparse, accuracy might be increased by repeated sampling. Diagnostic shift rarely alters postoperative treatment strategy. [ABSTRACT FROM AUTHOR]

Risk factors for prediction of prognosis in meningiomas derivable from routine preoperative magnetic resonance imaging (pMRI) remain elusive. Correlations of tumor and edema volume, disruption of the arachnoid layer, heterogeneity of contrast enhancement, enhancement of the capsule, T2-intensity, tumor shape, and calcifications on pMRI with tumor recurrence and high-grade (WHO grade II/III) histology were analyzed in 565 patients who underwent surgery for WHO grade I (N = 516, 91%) or II/III (high-grade histology, N = 49, 9%) meningioma between 1991 and 2018. Edema volume (OR, 1.00; p = 0.003), heterogeneous contrast enhancement (OR, 3.10; p < 0.001), and an irregular shape (OR, 2.16; p = 0.015) were associated with high-grade histology. Multivariate analyses confirmed edema volume (OR, 1.00; p = 0.037) and heterogeneous contrast enhancement (OR, 2.51; p = 0.014) as risk factors for high-grade histology. Tumor volume (HR, 1.01; p = 0.045), disruption of the arachnoid layer (HR, 2.50; p = 0.003), heterogeneous contrast enhancement (HR, 2.05; p = 0.007), and an irregular tumor shape (HR, 2.57; p = 0.001) were correlated with recurrence. Multivariate analyses confirmed tumor volume (HR, 1.01; p = 0.032) and disruption of the arachnoid layer (HR, 2.44; p = 0.013) as risk factors for recurrence, independent of histology. Subgroup analyses revealed disruption of the arachnoid layer (HR, 9.41; p < 0.001) as a stronger risk factor for recurrence than high-grade histology (HR, 5.15; p = 0.001). Routine pMRI contains relevant information about the risk of recurrence or high-grade histology of meningioma patients. Loss of integrity of the arachnoid layer on MRI had a higher prognostic value than the WHO grading, and underlying histological or molecular alterations remain to be determined. [ABSTRACT FROM AUTHOR]

Brain invasion (BI) is a new criterion for atypia in meningiomas and therefore potentially impacts adjuvant treatment. However, it remains unclear whether surgical practice and specimen characteristics influence histopathological analyses and the accuracy of detecting BI. Tumor location, specimen characteristics, and rates of BI were compared in meningioma samples obtained from 2938 surgeries in different neurosurgical departments but diagnosed in a single neuropathological institute. Non-skull base tumor location was associated with CNS tissue on the microscopic slides (OR 1.45; p <.001), increasing specimen weight (OR 1.01; p <.001), and remaining tissue not subjected to neuropathological analyses (OR 2.18; p <.001) but not with BI (OR 1.29; p =.199). Specimen weight, rates of residual tissue not subjected to histopathological analyses, of BI and of brain tissue, on the microscopic slides differed among the neurosurgical centers (p <.001, each). Frequency of BI was increased in one department (OR 2.07; p =.002) and tended to be lower in another (OR.61; p =.088). The same centers displayed the highest and lowest rates of brain tissue in the specimen, respectively (p <.001). Moreover, the correlation of BI with the neurosurgical center was not confirmed when only analyzing specimen with evidence of brain tissue in microscopic analyses (p =.223). Detection of BI was not correlated with the intraoperative use of CUSA in subgroup analyses. Rates of brain invasion in neuropathological analyses are not associated with tumor location but differ among some neurosurgical centers. Evidence raises that surgical nuances impact specimen characteristics and therefore the accuracy of the detection of BI. [ABSTRACT FROM AUTHOR]

We recently reported that the vast majority (>90%) of low-grade diffuse gliomas (diffuse astrocytoma, oligoastrocytoma and oligodendroglioma) carry at least one of the following genetic alterations: IDH1/2 mutation, TP53 mutation or 1p/19q loss. Only 7% of cases were triple-negative (ie, lacking any of these alterations). In the present study, array comparative genomic hybridization (CGH) in 15 triple-negative WHO grade II gliomas (eight diffuse astrocytomas and seven oligodendrogliomas) showed loss at 9p21 ( p14ARF, p15INK4b, p16INK4a loci) and 13q14-13q32 (containing the RB1 locus) in three and two cases, respectively. Further analyses in 31 triple-negative cases as well as a total of 160 non-triple-negative cases revealed that alterations in the RB1 pathway (homozygous deletion and promoter methylation of the p15INK4b, p16INK4a and RB1 genes) were significantly more frequent in triple-negative (26%) than in non-triple-negative cases (11%; P = 0.0371). Multivariate analysis after adjustment for age, histology and treatment showed that RB1 pathway alterations were significantly associated with unfavorable outcome for patients with low-grade diffuse glioma [hazard ratio, 3.024 (1.279-6.631); P = 0.0057]. These results suggest that a fraction of low-grade diffuse gliomas lacking common genetic alterations may develop through a distinct genetic pathway, which may include loss of cell-cycle control regulated by the RB1 pathway. [ABSTRACT FROM AUTHOR]

Estimating the risk of recurrence after surgery remains crucial during care of patients with meningioma. Numerous studies identified correlations of characteristics on routine preoperative magnetic resonance imaging (MRI) with postoperative recurrence or high-grade histology but showed partially inconclusive results. A systematic review of the literature was performed about findings on preoperative MRI and their correlation with high-grade histology and recurrence. Quality of the included studies was analyzed using standardized Quality Assessment of Diagnostic Accuracy Studies criteria. Among the 35 studies included, quality of the series according to the Quality Assessment of Diagnostic Accuracy Studies criteria differed widely. Remarkably, MRI variables found to be associated with high-grade histology were commonly not consistently associated with prognosis and vice versa. Correlations of the tumor size, the peritumoral edema size, and contrast-enhancement of the tumor capsule with high-grade histology were controversial. In most studies, non-skull base tumor location, cyst formation, heterogenous contrast-enhancement, an irregular tumor shape, and disruption of the tumor/brain border but not intensity of the lesion on T2-weighted images, calcifications, or bone involvement were associated with grade II/III histology. Although tumor and edema size were usually found to correlate with recurrence, heterogenous contrast enhancement, cyst formation, intensity of the tumor on T2-weighted MRI, and enhancement of the tumor capsule were mostly not related with progression. Several mostly consistent but partially inconsistent variables associated with high-grade histology or prognosis were identified. Although standardized studies are needed to provide further clarification, consideration of these findings can help to improve estimation of prognosis and can therefore improve postoperative care in patients with meningioma. [ABSTRACT FROM AUTHOR]