The study included 24 cases including 20 (83.3%) of female of intracranial meningiomas which were surgically operated in the hospital. The mean age of the respondents were 39.95 with 14.54 SD with a male female ratio 5:1. Most of the patients had WHO grade I tumor nearly 23 (95.8%) and regarding the location of the tumor, the most common location were convexity, parasagittal and posterior fossa including 6 (25%) of each. Most of the patients had meningothelial meningioma 18 (75.0%) (Table-1).
Most of the patients had G0 15 (62.5%) and G1, G2 had 8 (33.3%) and 1 (4.2%) respectively. The grading of the PTBE was statistically significant with the indices of Ki-67 (p < 0.05) (Table-2). The mean Ki-67 Index level represents the expansive activity of meningiomas, which was evaluated prospectively for all cases having a highest level 7.00 for G1 (Table-1).
Regarding the Ki-67 indices which is statistically not significant with gender, location of the tumor and type of meningiomas (p > 0.05) (Table-2). There were patients that had Ki-67 indices above 3%. Median Ki-67 value for GR0 is 2.00, for GR1 is 5.00. In GR0, these was range of Ki-67 value from minimum 1.00 to maximum 5.00, in GR1 Ki-67 value from minimum 3.00 to maximum 15.00 (Figure-3). In addition, spearman correlation test was done due the skewed distribution of the Ki-67 labelling index value compared to the grading of peritumoral edema. With a significant p-value of (P < 0.05) and a coefficient value of r = 0.647, the test demonstrates positive correlation. (Figure-4).
4.1 Comparison with other studies
Meningiomas are common primary central nervous system (CNS) tumors that are usually histologically benign, accounting for around 30% of primary adult intracranial tumors [14] [15]. Meningiomas often develop between the ages of 48 and 60, with a mean age of 48 and Alexiou et al. 2010 noted that, the incidence of meningiomas increases with ages, peaks after the fifth decade of life [16]. In our current study, majority of the respondents were among 31–40 years of age (29.1%) of age and second peak among the 21 to 30 years (25.0%) of age with the Mean studies ± SD 39.95 ± 14.54 years of the participants, which concurs with other previous [16]. With a female to male ratio of 2:1 to 2.5:1, meningiomas are diagnosed in women more often than in men; however, other publications have claimed a 3:1 ratio [17]. In our instance, just 20 out of 24 instances were found to be female, indicating a clear gender predominance. Previous findings have demonstrated increased growth rates of meningiomas during pregnancy and the luteal phases of the menstrual cycle, and they suggest that hormonal factors may be responsible for the preponderance of meningiomas in women [18].
Nonetheless, 80% of meningiomas are WHO grade I slow-growing tumors. A benign course is anticipated for WHO grade I meningiomas. Of all meningiomas, 15–20% are atypical meningiomas. One to three percent of instances of meningioma are anaplastic meningiomas, which share clinical traits with other malignant neoplasms [19]. The majority of cases in this study 23 (95.6%) were WHO grade I, which is also the most common in other investigations. Aguiar et al. discovered 28 instances (51%) GR0 group, 19 (34.5%) GR1, and 8 (14.5%) GR2. Simis et al. illustrated that almost 60% of meningiomas are linked to a peritumoral edema. The distribution of cases based on the edema grading in our study appears to be consistent with previous authors' findings, however the overall GR0 percentile is a little bit high, most likely because of the small study group [1].
PTBE is frequently detected in over 50% of meningiomas although, the exact cause of the development of PTBE with meningiomas is unknown, it is thought to be influenced by a number of variables, including patients age, gender, location of tumor and size, histology, and vascularity [20]. Compaction of the cerebral venous system next to the tumor is thought to be the source of increased PTBE, according to an established theory. According to one study, PTBE is brought on by increased permeability through the surrounding white matter fibers of the tumor, while another study proposed that the blood brain barrier is compromised [21]. However, in meningiomas that have been partly resected, higher Ki67 index levels are linked to faster doubling times and higher growth rates [22]. Aguiar et al., reported the mean LIs in the following groups GR0, GR1, and GR2 were 1.49 ± 1.62, 2.78 ± 3.36, and 5.43 ± 3.37, respectively. The mean values of Ki-67 labelling index of this particular study did not correspond to any other authors. This discrepancy is due to the lower number of cases and probably different tissue staining system in the histopathology lab.
Data on the correlation between the Ki67 index and specific variables, such as peritumoral edema, are, however, scarce. In this investigation, our objective was to ascertain whether there was a correlation between the Ki67 index values and the level of peritumoral edema surrounding meningiomas. There are known to be considerable differences in the expression level of Ki67 between benign (G0), atypical (G1), and anaplastic meningiomas (G2) [23]. Perry et al. proposed that a Ki67 index more than 4.2% was suggestive of strong tumor growth activity and recurrence in a study involving 62 cases of meningiomas [24]. In our study, the spearman correlation test was used to compare the grading of peritumoral edema with the Ki-67 labelling index and there was a statistically significant p value (P < 0.05) and a positive correlation coefficient of 0.647 thus it is possible to suggest a direct association between the two factors. whereas, these two factors were not found to be related in a study by Gawlitza et al. [6]. Meningioma without edema (GR0) in our study had high Ki67 values in some cases, which will direct a neurosurgeon to do a long-term follow-up because there is a high likelihood of recurrence.
In line with our results, Kim B-W et al. proposed in a study of 86 meningioma patients that greater Ki-67 antigen indices are linked to an increased frequency of PTBE. [25]. Although there is a substantial association between PTBE and Ki67 indices in other studies as well [21] [22] [26], more study with a bigger patient group and longer follow-up periods may be important indicator to definitively establish the clinical-relationship due to PTBE's limits and the various factors that influence it.
4.2 Strengths, Limitations, and Recommendations
This study is the first one we are aware of in Bangladesh that relates the Ki-67 antigen labeling index to PTBE. To continue with the limitations, the study is limited by its small sample size and its use of sampling from a single specialized facility. Furthermore, the cost and duration of immune-histochemical analysis remain high, and imaging patients using a piece of single-type equipment may help to minimize bias.
According to this study, for improved neurosurgical decision-making about follow-up, intracranial meningioma patients should have a ki-67 antigen labeling index and PTBE should be thoroughly documented during preoperative imaging.