Meningeal Solitary Fibrous Tumors with Delayed Extracranial Metastasis

Abstract

Background:The term solitary fibrous tumor (SFT) is preferred over meningeal hemangiopericytoma (HPC), because <i>NAB2-STAT6</i> gene fusion has been observed in both intracranial and extracranial HPCs. HPCs are now considered cellular variants of SFTs.Methods:This study analyzes 19 patients with STAT6-confirmed SFTs, who were followed for over 11 years in a single institution. Ten patients (10/19, 56.2%) had extracranial metastases (metastatic group), while the remainder (9/19) did not (non-metastatic group). These two groups were compared clinicopathologically.Results:In the metastatic group, the primary metastatic sites were the lungs (n = 6), bone (n = 4), and liver (n = 3). There was a mean lag time of 14.2 years between the diagnosis of the initial meningeal tumor to that of systemic metastasis. The median age at initial tumor onset was 37.1 years in the metastatic group and 52.5 in the non-metastatic group. The 10-year survival rates of the metastatic- and non-metastatic groups were 100% and 33%, respectively. The significant prognostic factors for poor outcomes on univariate analysis included advanced age (≥45 years) and large initial tumor size (≥5 cm). In contrast, the patients with higher tumor grade, high mitotic rate (≥5/10 high-power fields), high Ki-67 index (≥5%), and the presence of necrosis or CD34 positivity showed tendency of poor prognosis but these parameters were not statistically significant poor prognostic markers.Conclusions:Among patients with SFTs, younger patients (<45 years) experienced longer survival times and paradoxically had more frequent extracranial metastases after long latent periods than did older patients. Therefore, young patients with SFTs require careful surveillance and follow-up for early detection of systemic metastases.

Grading of meningeal solitary fibrous tumors/hemangiopericytomas: analysis of the prognostic value of the Marseille Grading System in a cohort of 132 patients

“…In previous studies, older age has been reported to be associated with worse overall survival for CNS SFT/HPC and for soft tissue SFT . Other clinical features like exact tumor location and tumor volume also reportedly provide prognostic information . Unfortunately, data regarding these features were only available for a limited subset of cases in our cohort and therefore could not be statistically analyzed.…”

“…Long‐term follow‐up is advised for all patients with a meningeal SFT/HPC regardless of grade, because recurrence(s) and/or metastasis can occur several years after initial diagnosis, even following complete surgical resection . It is important to note that such adverse events can also happen for meningeal SFT/HPC with the classic fibrous phenotype .…”

“…Therefore, WHO grade I SFTs/HPCs are characterized by the classic SFT phenotype and considered benign, while grade II and III SFTs/HPCs are characterized by the HPC phenotype and are considered malignant and are generally treated by surgery and adjuvant radiotherapy . Despite many reports of local recurrences, malignant progression and metastasis for neoplasms harboring the classical SFT phenotype , these tumors are still considered benign (i.e., WHO grade I). These cases question the benignity of classical SFT in the current WHO classification.…”

Multidisciplinary Management of Metastatic Hemangiopericytoma Presenting with Hypoglycemia

“…Histopathologic analysis of HPC reveals staghorn vasculature with spindle cells (Figure 2B), which alone is often insufficient to distinguish meningeal HPC from anaplastic meningioma [13]. For this reason immunohistochemistry has an important role in the diagnosis of these lesions.…”

Recurrent Intracranial Meningeal Hemangiopericytoma with an Isolated Bone Metastasis: A Case Report and Literature Review

“…One study reported that the median survival rates of patients with and without systemic metastases were 202 months and 99 months, respectively. [7] High rates of local recurrences, the development of distant metastases, the occurrence of metastases a long period after the initial surgery, and the appearance of synchronous metastases are characteristic features of this tumor. [8] Outcomes of chemotherapy for the management of metastatic disease, have been disappointing.…”