Nervous System Hemangiopericytoma

Parasagittal meningeal hemangiopericytoma/solitary fibrous tumor: Two case reports and a literature review

Background

Solitary fibrous tumor/meningeal hemangiopericytoma (SFT/M-HPC) is a rare neoplasm which accounts for around 1% of the intracranial masses. This pathology has a high risk for recurrence and metastasis to distant locations such as the liver, lungs, and bones. Precise diagnosis necessitates detailed histopathological examination.

Case Description

We present two case reports of SFT/M-HPC. The first case is a 44-year-old female who presented with headache, nausea, vomiting, and frontal ataxia for several months. Imaging findings showed a large parasagittal extra-axial mass with compression of the frontal horns of both lateral ventricles. She underwent gross total resection with an uncomplicated postoperative period. The patient had no recurrent tumors or distal metastases in the follow-up period of 5 years. The second case is a 48-year-old male who presented with right-sided hemianopsia and hemiparesis. Computed tomography (CT) scans revealed a large parieto-occipital extra-axial mass with superior sagittal sinus engulfment and dislocation of the interhemispheric fissure. He underwent gross total resection with an uncomplicated postoperative period. Six years later, he presented with right-sided weakness. CT scan showed a multifocal recurrent mass at the previous location. He underwent subtotal resection with an uncomplicated postoperative period.

Conclusion

SFT/M-HPC should be considered when presented with a meningioma-like tumor mass on preoperative imaging. Immunohistochemical study is crucial for the correct diagnosis. Strict long-term follow-up examinations and regular magnetic resonance imaging scans are key to preventing the appearance of metastases and large recurrent masses.

Radiotherapy for rare primary brain tumors

Rare central nervous system tumors are defined by an incidence rate of less than 6 cases per 100 000 individuals a year. It comprises a large panel of entities including medulloblastoma, glioneuronal tumors, solitary fibrous tumors, rare pituitary tumors, ependymal or embryonal tumors. The management of these tumors is not clearly defined and radiotherapy indications should be discussed at a multidisciplinary board. Image-guided and intensity-modulated radiation therapy should be proposed and MRI has a fundamental place in the treatment preparation. To avoid the occurrence of side effects, proton therapy is playing an increasingly role for the treatment of these tumors.

Malignant intracranial solitary fibrous tumor: A case report and literature review

Solitary fibrous tumor (SFT), previously termed hemangiopericytoma, is a rare primary intracranial tumor. SFT is classified into grades I, II, and III with different prognoses; grade III tumor has malignant characteristics with a high probability of recurrence and extracranial metastasis. We report the case of a 63-year-old female patient admitted to the Vietnam National Cancer Hospital with headache, dizziness, nausea, ataxia, and loss of balance. Computed tomography showed a markedly enhanced tumor, without calcification, located in the posterior fossa close to the tentorium cerebelli. No changes in the adjacent bone were seen. Magnetic resonance imaging revealed a lobular extra-axial tumor with prominent flow voids, a finding that has been seen frequently in these tumors. The tumor was resected following an initial diagnosis of SFT. Postoperative histology indicated a grade III SFT according to the World Health Organization 2021 classification. SFT is often misdiagnosed as meningioma, as they have some imaging features in common. However, we believe that there are some characteristic magnetic resonance imaging features that help to distinguish between these tumors, as well as playing an essential role in SFT grading and potentially guiding the best therapeutic decision.

Non-Invasive Preoperative Imaging Differential Diagnosis of Intracranial Hemangiopericytoma and Angiomatous Meningioma: A Novel Developed and Validated Multiparametric MRI-Based Clini-Radiomic Model

BACKGROUND

Accurate preoperative differentiation of intracranial hemangiopericytoma and angiomatous meningioma can greatly assist operation plan making and prognosis prediction. In this study, a clini-radiomic model combining radiomic and clinical features was used to distinguish intracranial hemangiopericytoma and hemangioma meningioma preoperatively.

METHODS

A total of 147 patients with intracranial hemangiopericytoma and 73 patients with angiomatous meningioma from the Tiantan Hospital were retrospectively reviewed and randomly assigned to training and validation sets. Radiomic features were extracted from MR images, the elastic net and recursive feature elimination algorithms were applied to select radiomic features for constructing a fusion radiomic model. Subsequently, multivariable logistic regression analysis was used to construct a clinical model, then a clini-radiomic model incorporating the fusion radiomic model and clinical features was constructed for individual predictions. The calibration, discriminating capacity, and clinical usefulness were also evaluated.

RESULTS

Six significant radiomic features were selected to construct a fusion radiomic model that achieved an area under the curve (AUC) value of 0.900 and 0.900 in the training and validation sets, respectively. A clini-radiomic model that incorporated the radiomic model and clinical features was constructed and showed good discrimination and calibration, with an AUC of 0.920 in the training set and 0.910 in the validation set. The analysis of the decision curve showed that the fusion radiomic model and clini-radiomic model were clinically useful.

CONCLUSIONS

Our clini-radiomic model showed great performance and high sensitivity in the differential diagnosis of intracranial hemangiopericytoma and angiomatous meningioma, and could contribute to non-invasive development of individualized diagnosis and treatment for these patients.

Central nervous system solitary fibrous tumour/hemangiopericytoma presenting as nausea, vomiting and hepatic dysfunction after the first trimester of pregnancy: A case report

Background

Solitary fibrous tumour/haemangiopericytoma (SFT-HPC) is a rare fibroblastic mesenchymal neoplasm that develops as a result of the uncontrolled proliferation of mesenchymal fibroblasts and occurs rarely during pregnancy.

Case Presentation

A 26-year-old woman (G₂P₁) with an intrauterine pregnancy at 34⁺⁴weeks presented at a university hospital with a history of nausea and vomiting since 20 weeks. Other symptoms included slight headache and 5-kg weight loss. She had attended and been admitted to several hospitals during that time. Laboratory evaluation revealed evidence of hepatic dysfunction with elevated liver enzymes. The patient's headache worsened, and magnetic resonance imaging (MRI) showed an extra-axial mass in the right tentorial and supratentorial spaces, with brain herniation. Caesarean section and brain tumour resection were performed under general anaesthesia at the same time. Histopathological analysis revealed HPC (World Health Organization [WHO] grade III). Nausea and vomiting symptoms gradually improved. Postoperatively, the patient underwent fractional external radiotherapy (total amount 50 Gy). There was no evidence of local recurrence of metastases in the follow-up 6 months after surgery.

Conclusions

Nausea and vomiting are commonly experienced during pregnancy. This often makes patients ignore other aetiologies that cause nausea and vomiting. Central nervous system tumours can mimic the common pregnancy complaint of nausea and vomiting. Although rare in pregnancy, they can adversely affect maternal and fetal survival if untreated. Clinicians should exclude other pathology when the onset of nausea and vomiting is after the first trimester.

•

Haemangiopericytoma is a rare and aggressive type of soft tissue sarcoma that arises from pericytes of the capillaries and involves mostly the musculoskeletal system.

•

Its presentation [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11]] in the central nervous system is very rare.

•

Diagnosis was made at 34 weeks of pregnancy after several hospital admissions for nausea and vomiting starting at 20 weeks gestation.

•

There should be a suspicion of pathology when the onset of nausea and vomiting is after the first trimester.

[What's new in the management of meningeal solitary fibrous tumor/hemangiopericytoma?]

Meningeal fibrous solitary tumors/hemangiopericytoma are rare and aggressive mesenchymal neoplasms considered as sarcomas. They represent less than 1% of intracranial tumors and derive from the pericytes of Zimmerman which permit capillary contraction. They tend to occur more often in males in the fifth decade. They are often revealed by intracranial hypertension. Some scannographic and MRI characteristics permit to distinguish meningeal fibrous solitary tumor/hemangiopericytoma from other meningeal tumors. Meningeal hemangiopericytoma and fibrous solitary tumors were considered as different entities until 2016. Following the discovery of an identical genetic event, the locus 12q13 chromosome inversion leading to a NAB2-STAT6 fusion with nuclear immunoreactivity for STAT6 protein, the 2016 WHO classification defines these tumors as a single entity. Meningeal fibrous solitary tumors/hemangiopericytoma have a high recurrence rate. Long-term recurrences may occur. Local relapses are more frequent than extracranial metastasis. A multimodal management is recommended to treat a localized disease. It involves a complete resection followed by adjuvant radiotherapy. When local recurrences occur, surgery or stereotactic radiosurgery permit sometimes a local control. Metastatic disease has a poor prognostic and a weak chimiosensitivity. Targeted therapies, like pazopanib, are a hopeful option.