Intracranial anaplastic solitary fibrous tumor/hemangiopericytoma: immunohistochemical markers for definitive diagnosis

Neurosurg Rev. 2021 Jun;44(3):1591-1600. doi: 10.1007/s10143-020-01348-6. Epub 2020 Jul 15.


Intracranial anaplastic hemangiopericytoma (AHPC) is a rare and malignant subset of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) as per the WHO 2016 Classification of Tumors of the Central Nervous System. AHPC portends a poor prognosis and is associated with higher rates of recurrence/metastasis in comparison with SFT/HPC. Accordingly, it is critical to continue to define the clinical course of patients with AHPC and in so doing further refine clinicopathologic/immunohistochemical (IHC) criteria needed for definitive diagnosis. Herein, we describe clinical/histological characteristics of six patients with AHPC. In addition, we reviewed and analyzed the expression of various IHC markers reported within the literature (i.e., a total of 354 intracranial SFT/HPCs and 460 meningiomas). Histologically, tumors from our six patients were characterized by a staghorn-like vascular pattern, mitotic cells, and strong nuclear atypia. Immunohistochemically, all tumors displayed positive nuclear staining for STAT6; other markers, including CD34 and Bcl-2, were expressed only in three patients. Analysis of IHC expression patterns for SFT/HPC and meningioma within the literature revealed that nuclear expression of STAT6 had the highest specificity (100%) for SFT/HPC, followed by ALDH1 (97.2%) and CD34 (93.6%). Of note, SSTR2A (95.2%) and EMA (85%) displayed a high specificity for meningioma. Anaplastic SFT/HPC is a tumor with poor prognosis that is associated with higher rates of recurrence and metastasis in comparison with SFT/HPC. Given that anaplastic SFT/HPC requires more aggressive treatment than meningioma despite of a similar presentation on imaging, it is crucial to be able to distinguish between these tumors.

Keywords: Anaplastic; Hemangiopericytoma; Meningioma; STAT6; Solitary fibrous tumor.

Publication types

  • Review

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor / metabolism*
  • Diagnosis, Differential
  • Female
  • Follow-Up Studies
  • Hemangiopericytoma / diagnostic imaging
  • Hemangiopericytoma / metabolism*
  • Hemangiopericytoma / surgery
  • Humans
  • Male
  • Meningeal Neoplasms / diagnostic imaging
  • Meningeal Neoplasms / metabolism*
  • Meningeal Neoplasms / surgery
  • Meningioma / diagnostic imaging
  • Meningioma / metabolism*
  • Meningioma / surgery
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnostic imaging
  • Neoplasm Recurrence, Local / metabolism*
  • Neoplasm Recurrence, Local / surgery
  • STAT6 Transcription Factor / metabolism
  • Solitary Fibrous Tumors / diagnostic imaging
  • Solitary Fibrous Tumors / metabolism*
  • Solitary Fibrous Tumors / surgery


  • Biomarkers, Tumor
  • STAT6 Transcription Factor
  • STAT6 protein, human