Correlation of progesterone receptors and P63 to the histological grade of meningiomas: Review and significance in an African population

Objectives

Meningiomas, a common neoplasm of the central nervous system, is a widely studied meningeal tumor. According to the World Health Organization (WHO) 2021 classification of meningiomas, there are 15 subtypes that have been grouped into grades 1, 2, and 3. The WHO grade 1 meningiomas are generally grouped as benign while the WHO grades 2 and 3 tumors are grouped as malignant. Progesterone receptors and P63 are common immunohistochemical markers that have proven useful in the diagnosis, grading, and prognostication of many neoplasms such as breast carcinoma, prostate carcinoma, and gastrointestinal tumors in histopathology practice. The application of these immunohistochemical markers to the grading of meningiomas has been reported and their usefulness documented in reports from Africa, Europe, North America, South America, and Asia. This study, therefore, seeks to determine if these findings are applicable to the meningiomas seen in an African population.

Materials and Methods

A 10-year review of results and histologically diagnosed cases of meningiomas received in the Department of Morbid Anatomy, University of Nigeria, Enugu. Immunostaining for progesterone receptors (PgRs) and P63 were done and results compared with histologic grades.

Results

The three WHO grades of meningioma were assessed in this study. M: F ratio was 1:1.4 and peak age was 41-50 years age range (SD ± 16.54). The majority of the cases were WHO grade 1 (86.1%) while the WHO grades 2 and 3 tumors were 8% and 5.9%, respectively. The fibrous variant was the most common subtype (27.1%). There was no correlation between progesterone receptor and P63 immunopositivity to the WHO grades of meningioma (P = 0.112 and P = 0.138, respectively).

Conclusion

Our study showed that progesterone receptors and P63 immunopositivity did not correlate with the WHO grades of meningiomas. This may be due to the predominant variant of meningioma seen in this study. These findings indicate that PgR antagonist may not be an effective alternative for treatment in patients with inoperable meningiomas. Furthermore, P63 immunopositivity may not be a sufficient grading tool for managing meningiomas in our population.

Metastatic atypical meningioma to the parotid gland - A cytopathological correlation

The tumors involving the parotid gland are mainly primary, with metastatic lesions comprising only 5% of malignant salivary gland neoplasms. We are presenting a rare case of metastatic meningioma to the parotid in a 51-year-old male with a past medical history of recurrent atypical meningioma involving the frontal lobe. For the past 1.5 years, routine imaging showed parotid lesions with interval growth including a 2.0 cm dominant tender preauricular parotid mass. The chronicity and the number of lesions made malignancy unlikely. The differential diagnosis included non-specific lesions such as intraparotid lymph nodes and benign neoplasms. Fine needle aspiration of the parotid mass was performed to show loosely cohesive fragments and singly scattered neoplastic cells with mild nuclear pleomorphism and oncocytic cytoplasm. The main cytomorphologic differential diagnosis included oncocytic and myoepithelial-rich tumors. The neoplastic cells were immunoreactive to p63, calponin and SSTR2A and were negative for cytokeratins, progesterone receptor, S100, DOG-1, EMA, synaptophysin, and chromogranin. The cytology slides and the parotid gland mass resection were compared to the previous meningioma resection specimen which showed a similar morphology of the oncocytic tumor cells in some areas. The overall morphologic and immunohistochemical findings of the parotid tumor were consistent with metastatic meningioma. Extracranial metastases from intracranial tumors are extremely rare. Meningiomas arise from the dura matter, constitute 15% of primary brain tumors, and metastasize at an estimated rate of 0.1%. Despite how uncommon metastatic meningioma is, our case emphasizes the critical role of clinical history when evaluating parotid gland lesions.

Proteomic analysis of meningiomas reveals clinically distinct molecular patterns

BACKGROUND

Meningiomas represent one of the most common brain tumors and exhibit a clinically heterogeneous behavior, sometimes difficult to predict with classic histopathologic features. While emerging molecular profiling efforts have linked specific genomic drivers to distinct clinical patterns, the proteomic landscape of meningiomas remains largely unexplored.

METHODS

We utilize liquid chromatography tandem mass spectrometry with an Orbitrap mass analyzer to quantify global protein abundances of a clinically well-annotated formalin-fixed paraffin embedded (FFPE) cohort (n = 61) of meningiomas spanning all World Health Organization (WHO) grades and various degrees of clinical aggressiveness.

RESULTS

In total, we quantify 3042 unique proteins comparing patterns across different clinical parameters. Unsupervised clustering analysis highlighted distinct proteomic (n = 106 proteins, Welch's t-test, P < 0.01) and pathway-level (eg, Notch and PI3K/AKT/mTOR) differences between convexity and skull base meningiomas. Supervised comparative analyses of different pathological grades revealed distinct patterns between benign (grade I) and atypical/malignant (grades II‒III) meningiomas with specific oncogenes enriched in higher grade lesions. Independent of WHO grade, clinically aggressive meningiomas that rapidly recurred (<3 y) had distinctive protein patterns converging on mRNA processing and impaired activation of the matrisome complex. Larger sized meningiomas (>3 cm maximum tumor diameter) and those with previous radiation exposure revealed perturbed pro-proliferative (eg, epidermal growth factor receptor) and metabolic as well as inflammatory response pathways (mitochondrial activity, interferon), respectively.

CONCLUSIONS

Our proteomic study demonstrates that meningiomas of different grades and clinical parameters present distinct proteomic profiles. These proteomic variations offer potential future utility in helping better predict patient outcome and in nominating novel therapeutic targets for personalized care.

Expression of p40 (∆Np63) protein in meningiomas, an unexpected finding: immunohistochemical study and evaluation of its possible prognostic role

According to the 2007 WHO (World Health Organization) Classification, meningiomas are divided into three grades of malignancy, with different recurrence rate, based exclusively on histopathological parameters. Loss/reduction of PgR (Progesterone Receptor) expression and increased Ki67 L.I. (Labeling Index) have been proven as possible prognostic factors able to predict the relapse of the disease. However, they sometimes result unreliable, especially when discordant. p40 is the short form of the p53 homologue gene p63, also named ∆Np63, and its antibody has recently been introduced as a highly specific diagnostic marker of the squamous cell carcinoma of the lung. Nevertheless its expression has been found in many other unconventional sites (e.g. placenta, urotheluim, etc). Herein we assessed the immuno-expression of p40 protein in a series of 72 meningiomas (35 grade I and 37 grade II) and analyzed its correlation with clinicopathological parameters, overall survival and recurrence free interval. We found that a high p40 score correlated with high histological grade, presence of recurrence, increased Ki67 L.I. and loss/reduction of PgR signal. Moreover, a higher expression of p40 was shown to be a significant prognostic factor for the development of recurrences and resulted a prognostic independent variable in multivariate analysis. Overall, for the first time, we investigated the expression of p40 protein in meningiomas and explored its usefulness as prognostic marker in addition to PgR and Ki67 L.I.

Differentially Expressed MicroRNAs in Meningiomas Grades I and II Suggest Shared Biomarkers with Malignant Tumors

Meningiomas represent the most common primary tumors of the central nervous system, but few microRNA (miRNA) profiling studies have been reported so far. Deep sequencing of small RNA libraries generated from two human meningioma biopsies WHO grades I (benign) and II (atypical) were compared to excess dura controls. Nineteen differentially expressed miRNAs were validated by RT-qPCR using tumor RNA from 15 patients and 5 meninges controls. Tumor suppressor miR-218 and miR-34a were upregulated relative to normal controls, however, miR-143, miR-193b, miR-451 and oncogenic miR-21 were all downregulated. From 10 selected putative mRNA targets tested by RT-qPCR only four were differentially expressed relative to normal controls. PTEN and E-cadherin (CDH1) were upregulated, but RUNX1T1 was downregulated. Proliferation biomarker p63 was upregulated with nuclear localization, but not detected in most normal arachnoid tissues. Immunoreactivity of E-cadherin was detected in the outermost layer of normal arachnoids, but was expressed throughout the tumors. Nuclear Cyclin D1 expression was positive in all studied meningiomas, while its expression in arachnoid was limited to a few trabecular cells. Meningiomas of grades I and II appear to share biomarkers with malignant tumors, but with some additional tumor suppressor biomarkers expression. Validation in more patients is of importance.

Support for p63 expression as an adverse prognostic marker in Merkel cell carcinoma: report on a Canadian cohort

Recent evidence has invoked immunohistochemical expression of p63 in Merkel cell carcinoma as an adverse prognostic factor. Conflicting data led us to evaluate this. An Eastern Canadian cohort diagnosed between 1990 and 2012 was studied. Demographic and clinical data were obtained from pathology records and Provincial Cancer Registries. Pathological features were evaluated by the investigators. Merkel cell polyomavirus status was known in a subset of cases. Clinicopathological features were correlated with overall survival. The cohort consisted of 83 patients (mean age, 75.8 ± 11.7 years) with a male/female ratio of 1.24:1. In a mean follow-up period of 175 weeks (±177), 51 patients died (61.4%). Of several parameters examined, 6 showed significant adverse associations with survival on univariate analysis: age (hazard ratio [HR], 1.05 [1.02-1.08]), clinical stage (III/IV versus I/II; HR, 2.24 [1.18-4.27]), tumor size (HR, 1.16 [1.05-1.28]), combined versus pure morphology (HR, 1.82 [1.04-3.18]), minimal tumor-infiltrating lymphocytes (HR, 2.23 [1.04-4.78]), and expression of p63 (positive in 49.4%; HR, 1.93 [1.09-3.43]). In the stage I/II subgroup, p63 expression was associated with a trend toward poor survival. On multivariate analysis, p63 expression was not significantly associated with reduced survival. Our data support existing evidence that p63 expression in Merkel cell carcinoma carries adverse implications for survival. That it was not an independent prognostic factor may be due to study size and/or its potential as a confounding variable with clinical stage. Of clinical importance is its association with a trend toward a poor outcome in early stage disease.

Cutaneous meningioma: a potential diagnostic pitfall in p63 positive cutaneous neoplasms

Cutaneous meningiomas are divided into three groups. Type I lesions present at birth and are derived from ectopic arachnoid cells. Type II lesions usually present in adults and are derived from arachnoid cells surrounding nerve bundles. Type III lesions are due to direct extension or metastasis from dural-based neoplasms. Dural-based meningiomas are known to express p63. The aim of our study is to examine the expression of p63 in type II and type III meningioma. Two cases of cutaneous meningioma (type II and type III) were evaluated for the expression of p63, EMA, CK 5/6, S100 and CD31. The cells of interest were spindled to epithelioid and arranged in a whorling pattern. Immunohistochemical staining showed expression of EMA and p63 in both cases, while stains for CK 5/6, S100 and CD31 were negative. Among cutaneous tumors, p63 is considered a marker of epithelial derivation, as it is positive in epidermal and adnexal neoplasms. It is important to be aware of p63 expression in the context of cutaneous meningioma to avoid misinterpretation as an epithelial tumor. On the basis of our small study, it is unlikely that p63 expression would be helpful in distinguishing between type II and type III meningioma, as both may be p63-positive.