[Papillary meningioma: a very rare and aggressive variant of meningioma]

Papillary meningioma of the central nervous system: a SEER database analysis

Papillary meningioma (PM) is a rare central nervous system tumor. We aimed to analyze the characteristics and outcomes of patients with PM (WHO grade III) and identify risk factors that influence survival using the Surveillance, Epidemiology, and End Results (SEER) database. Clinical characteristics, tumor features, and outcomes of 108 PM patients included in the SEER database between 1990 and 2016 were retrieved. Risk factors related to prognosis of PM were assessed by Kaplan-Meier curves and the Cox proportional hazards model. All 108 patients, including 65 males and 43 females (1.5:1), with a median age of 52 years (range, 9 to > 85 years) had undergone surgical resection. Gross total resection (GTR) was achieved in 50%, and 50% underwent subtotal resection (STR). While 55.6% underwent postoperative radiation therapy, 48% did not. The median disease-specific survival (DSS) was 128 months, and the 5-year DSS rate was 77%. In multivariate analysis, age ≤ 52 years and GTR were both independently associated with higher probability of DSS (p = 0.033 and p = 0.029, respectively). Stratification analysis showed that postoperative radiotherapy had no significant impact on the DSS, irrespective of resection extent (p = 0.172). Our SEER analysis showed that age and extent of resection were prognostic factors for PM, but race, tumor size, gender, chemotherapy, and postoperative radiotherapy did not significantly impact DSS of PM patients. There was no significant improvement in survival of patients who underwent radiotherapy and GTR, or radiotherapy and STR, compared with GTR or STR alone.

Immunohistochemical Expression of Progesterone Receptors in Nonmeningothelial Central Nervous System Tumors

INTRODUCTION

Immunostaining of progesterone receptors (PRs) has been described as a prognostic factor related to recurrences in meningiomas. However, its expression in other primary intracranial tumors has been poorly studied. In this paper, we compare the pattern of expression of the receptor in meningiomas with that of nonmeningothelial intracranial tumors to evaluate its value in the diagnosis of the former.

MATERIALS AND METHODS

A total of 42 nonmeningothelial intracranial tumors (21 glioblastomas, 4 anaplastic oligodendrogliomas, 4 oligodendrogliomas, 1 pilomyxoid astrocytoma, 3 ependymomas, 8 schwannomas, 1 chordoid chordoma) and 32 meningiomas (1 rhabdoid, 1 papillary, 5 atypical, 7 with histologic features of more aggressive behavior, 1 microcyst, 8 meningothelial, 7 transitional, 2 fibroblastic) were studied for PR by immunohistochemistry.

RESULTS

About 73.8% of the nonmeningothelial tumors and 100% of the meningiomas were positive for the receptor, the difference being statistically significant (P=0.0017). The mean percentage of positive tumor cells per high-power field was frequently higher than 30% in meningiomas and lower than 10% in nonmeningothelial tumors (P=0.0001).

CONCLUSIONS

Although we detected that immunostaining for the PR is more frequently observed in meningiomas, we confirmed its expression in diverse nonmeningothelial primary intracranial tumors. Immunohistochemistry for PR would be useful in the diagnosis of meningioma only when its positivity shows a mean higher than 30% of the positive tumor cells per high-power field.