The status of MGMT protein expression is a prognostic factor for meningeal hemangiopericytoma: a clinicopathologic and immunohistochemical study of 12 cases at a single institution

Liver metastasis and local recurrence of meningeal hemangiopericytoma: a case report

This report describes the clinical features, diagnostic and treatment modalities of a 62-year-old female patient with liver metastasis and local recurrence of meningeal hemangiopericytoma (HPC), who presented with the clinical manifestations of memory deterioration, visual reduction and abdominal mass for one month. Skull and abdominal computed tomography (CT), magnetic resonance imaging (MRI) and 18FFluorodeoxyglucose positron emission tomography (FDG-PET)-CT were used for pre-surgery identification. Lesions without FDG uptake and less tumoral viability was observed through FDG-PET-CT, which was characteristic features of HPC before operation. The intraoperative specimens from the liver resection and the calvarium were pathologically examined for further confirming the diagnosis. The patient underwent liver resection and bilateral frontal cerebral convex and parafalx resection as well as intracranial pressure sensor implantation for liver metastasis and local recurrence of HPC respectively. The patient recovered well and no recurrence or distant metastasis was found after 2-year follow-up. Early diagnosis and long-term follow-up are crucial for patients with hepatic metastasis or local recurrence of HPC, and FDG-PET-CT is recommended as an ideal imaging tool. Radical resection of HPC lesions is considered as an optimal treating approach.

Meningeal hemangiopericytomas: a clinicopathological study with emphasis on MGMT (O(6) -methylguanine-DNA methyltransferase) promoter methylation status

Meningeal hemangiopericytomas (HPCs) are aggressive dural-based tumors, for which no prognostic or predictive marker has been identified. Gross total resection is treatment of choice, but not easily achieved; hence, alkylating agents like temozolomide (TMZ) are now being tried. O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation has proven prognostic and predictive value in glioblastomas. This study evaluates MGMT promoter methylation in meningeal HPCs to determine its role in HPC oncogenesis and its association with patient outcome. Meningeal HPCs diagnosed between 2002 and 2011 were retrieved and clinicopathological features reviewed. MGMT promoter methylation status was assessed by methylation-specific polymerase chain reaction (MSP) and immunohistochemistry (IHC) for MGMT protein. HPCs accounted for 1.1% of all CNS tumors. Forty cases were analyzed; the majority were adults (mean age = 41.4 years). Seventy percent were primary and 30% were recurrent tumors; 60% were grade II and 40% were grade III. MGMT promoter methylation was identified in 45% of cases, including Grade II (54.2%) and Grade III (31.3%) (P = 0.203). Promoter methylation was significantly (P = 0.035) more frequent in primary (57.1%) than in recurrent (16.7%) tumors. No correlation was noted between MGMT promoter methylation by MSP and MGMT protein expression by IHC, or with progression-free survival. Thus, a significant proportion of HPCs demonstrate MGMT promoter methylation, suggesting possible susceptibility to TMZ. As promoter methylation is more frequent in primary tumors, TMZ may serve as a therapeutic option in residual primary tumors. Epigenetic inactivation of MGMT in HPCs necessitates the assessment of prognostic and predictive value of MGMT promoter methylation in HPCs in larger clinical trials.

Solitary fibrous tumors and hemangiopericytomas of the meninges: overlapping pathological features and common prognostic factors suggest the same spectrum of tumors

Meningeal solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) are distinct entities in the World Health Organization (WHO) classification of central nervous system (CNS) tumors while they belong to the same spectrum of tumors in other locations. Well-defined histological prognostic factors are also lacking for these tumors. In order to clarify the relationship between SFT and HPC and to find histological and immunohistochemical prognostic factors, we carried out a retrospective study in 89 patients. The following histological parameters were recorded: hypercellularity, collagenic areas, cytonuclear atypias, necrosis, mitotic count per 10 high-power fields, vasculo-nervous adherences defined by engulfment of vessel or nerve by the tumor, brain infiltration. We found overlapping histological and immunohistochemical features between SFT and HPC. The most relevant histological prognostic factors in the whole cohort for both progression-free survival (PFS) and overall survival (OS) in univariate analysis were hypercellularity, high mitotic count (>5 per 10 high-power fields) and necrosis. On the basis of these results, we propose a new grading scheme for these tumors which was of pronostic value for both PFS and OS in uni- and multivariate analysis. As extent of surgery was also a prognostic factor for both PFS and OS in univariate analysis, we propose that management of SFT/HPC might be based both on quality of removal and histological grade.