obsolete central nervous system hemangiopericytoma

Hemangiopericytoma: An Obsolete Term

Hemangiopericytoma, also known as solitary fibrous tumor (SFT), is a rare type of nonmeningothelial mesenchymal neoplasm that originates in the meninges. It was previously considered a distinct entity from other types of tumors, but recent classifications have rendered it obsolete.

Characteristics

• Hemangiopericytomas are characterized by the presence of neoplastic spindle-shaped to round cells.
• They can be benign or malignant and are typically found in the central nervous system (CNS).
• The 5-year survival rate for patients with hemangiopericytoma of the CNS has improved over the years, but it is still a rare and aggressive tumor.

Classification

• In 2021, the World Health Organization (WHO) classification of tumors of the CNS replaced the term "hemangiopericytoma" with "solitary fibrous tumor".
• Solitary fibrous tumors are now considered to be part of a histologic spectrum of rarely metastasizing fibroblastic mesenchymal neoplasms.

Incidence

• Hemangiopericytomas or solitary meningeal fibrous tumors are extremely rare, representing only 1.6% of all CNS tumors.
• They are more common in adults and have a slight predilection for females.

References

• [2] The 5-year survival rate in patients with hemangiopericytoma of the CNS has improved at the authors' institution during the last 10 years.
• [3] Solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) both entered the literature as separate entities in the early to mid 1900s.
• [8] The 2021 WHO classification of the tumors of the CNS renders the term “hemangiopericytoma” obsolete and replaces it fully with “solitary fibrous tumor”.
• [9] Intracranial solitary fibrous tumors (ISFTs) are rare nonmeningothelial mesenchymal neoplasms originating in the meninges.
• [10] An obsolete term referring to hemangiopericytoma of the central nervous system.

Common Chief Complaints

The symptoms of central nervous system (CNS) hemangiopericytoma, also known as solitary fibrous tumor/hemangiopericytoma, are non-specific and often similar to those of other types of tumors. The common chief complaints include:

• Headache [3][5]
• Imbalance [3]
• Weakness [3]
• Visual complaints [3]
• Cranial nerve dysfunction [3]
• Nausea [3]
• Confusion [3]

These symptoms can vary depending on the location and size of the tumor, as well as the individual's overall health.

Other Symptoms

In addition to these common chief complaints, other symptoms may include:

• Frontal ataxia (difficulty with coordination and balance) [7]
• Vomiting [7]
• Dizziness [10]

It is essential to note that these symptoms can be similar to those of other conditions, making it crucial for a proper diagnosis by a medical professional.

References

[1] MP Ciliberti · 2018 - The symptoms of this type of tumor are non-specific and often similar to those of other types of tumors...

[2] S Swaminathan · 2022 - Following microsurgical resection of SFT/HPC, CNS relapse is common and associated with age, extent of resection, and adjuvant radiation.

[3] AC Piccardo · 2024 - Common chief complaints are headache, imbalance, weakness, visual complaints, cranial nerve dysfunction, nausea, and confusion.

[5] AC Piccardo · 2024 - The clinical course is usually ...

[7] Apr 19, 2024 - The first case is a 44-year-old female who presented with headache, nausea, vomiting, and frontal ataxia. Magnetic resonance imaging (MRI) scans...

[10] Most HPCs are located in the musculoskeletal system and the skin, while central nervous system HPCs are rare, with a prevalence of only 1%. HPCs usually affect adults in their fourth to fifth decade of life, with a slight male predominance. The clinical symptoms generally consist of headache and dizziness.

Treatment Options for Obsolete Central Nervous System Hemangiopericytoma

Hemangiopericytoma (HPC), also known as solitary fibrous tumor of the central nervous system (CNS), is a rare mesenchymal tumor that arises from the pericytes of the meningeal capillaries. While the term "hemangiopericytoma" is considered obsolete, the treatment options for this condition remain relevant.

Chemotherapy

Chemotherapeutic agents such as doxorubicin and ifosfamide have been used in combination with other treatments to manage residual tumor after surgical resection [2]. However, the effectiveness of chemotherapy in treating HPC remains unclear.

Targeted Therapy

Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor (VEGF), has been used in combination with temozolomide to treat HPC. This combination therapy has shown promise as a generally well-tolerated and clinically beneficial regimen [3].

Immunotherapy

Recent studies have explored the potential of immunotherapy modalities, such as checkpoint inhibitors, in treating select rare CNS tumors, including HPC [4]. However, more research is needed to fully understand the role of immunotherapy in managing this condition.

Radiation Therapy

Highly conformal radiation therapy (RT) and stereotactic radiosurgery (SRS) can achieve long-term control of HPCs, especially in cases with multiple recurrences [6].

Multimodal Treatment

A combination of surgical resection, chemotherapy, targeted therapy, immunotherapy, and radiation therapy may be necessary to manage HPC effectively. The patient's individual characteristics and tumor behavior will dictate the most appropriate treatment approach.

References:

[1] Rodriguez A (2023) - Preclinical and clinical data of various immunotherapy modalities in select rare CNS tumors. [2] Ecker RD et al. (2003) - Salvage chemotherapy for residual tumor after surgical resection of HPC. [3] Park MS et al. (2011) - Combination therapy with temozolomide and bevacizumab for HPC. [4] Bao P et al. (2022) - Immunotherapy in the treatment of rare CNS tumors, including HPC. [6] Lee JH et al. (2020) - Stereotactic radiosurgery for HPC: a systematic review and meta-analysis.

Note: The term "obsolete" refers to the fact that the term "hemangiopericytoma" is no longer used in modern pathology, but rather replaced by "solitary fibrous tumor of the central nervous system".

Differential Diagnosis of Obsolete Central Nervous System Hemangiopericytoma

The differential diagnosis of obsolete central nervous system (CNS) hemangiopericytoma involves distinguishing it from other types of tumors, particularly solitary fibrous tumor (SFT) and angiomatous meningioma. According to the 2021 WHO classification of CNS tumors, the term "hemangiopericytoma" is considered obsolete and replaced with "solitary fibrous tumor" [2][6].

Key Diagnostic Features

To differentiate SFT from HPC, several key features are considered:

• Immunohistochemical evaluations: Newer immunohistochemical evaluations can be used to effectively diagnose SFT, HPC, and meningioma [10].
• ADC maps: Whole-tumor histogram analysis of ADC maps may be a useful tool for differential diagnosis, with ADCmin and ADC5 being potential parameters [13].
• Imaging features: Imaging studies such as CT and MRI can help differentiate between these tumors, although they remain a diagnostic challenge preoperatively [8].

Differential Diagnosis from SFT

The differential diagnosis of HPC from SFT is somewhat more important due to the benign prognosis of SFTs. However, distinguishing SFT from HPC can be challenging, and newer immunohistochemical evaluations may be necessary for accurate diagnosis [10][11].

References

[2] Cekov AH (2024) - The 2021 WHO classification of CNS tumors renders the term "hemangiopericytoma" obsolete and replaces it fully with "solitary fibrous tumor".

[6] Apr 19, 2024 - The 2021 WHO classification of CNS tumors renders the term "hemangiopericytoma" obsolete and replaces it fully with "solitary fibrous tumor".

[8] SAHOO N (Cited by 3) - Due to its rarity and clinical and radiological resemblance to other more common brain tumors, they remain a diagnostic challenge preoperatively.

[10] Objectives: Hemangiopericytomas (HPCs) are rare neoplasms with relatively high rates of recurrence and extracranial metastasis. Though the differential diagnoses from SFT and meningioma are somewhat more important in light of the benign prognosis of SFTs.

[11] Now, however, newer immunohistochemical evaluations for SFT, HPC, and meningioma can be effectively used for the different diagnosis of these three tumors.

[13] Yin and Geng 35 Whole-tumor histogram analysis of ADC maps may be a useful tool for differential diagnosis, with ADCmin and ADC5 being potential parameters.