What Is the Difference Between SFT and Hemangiopericytoma?

If you are reading your pathology report and seeing the word hemangiopericytoma while your doctor is calling it a solitary fibrous tumor (SFT), you might feel confused or worried that you have been misdiagnosed. The short answer is: they are essentially the exact same disease ^[1]. Historically, doctors thought they were two different conditions, but recent scientific discoveries proved they are different names for the same type of tumor ^[2]. Today, the medical community prefers to use “solitary fibrous tumor” as the umbrella term for both.

A Shared Root: Genetics and Location

For decades, pathologists categorized tumors based on how they looked under a microscope and where they were located in the body. The term hemangiopericytoma was most often used for tumors found in the central nervous system (the brain and spinal cord), while solitary fibrous tumor was traditionally used for tumors found elsewhere, like the chest lining (pleura) or soft tissues ^[1].

Medical understanding shifted dramatically when researchers discovered a specific genetic mutation called the NAB2-STAT6 gene fusion ^[3]. A gene fusion happens when two different genes accidentally break and join together. Scientists found that this exact same gene fusion is the underlying cause of both SFTs and hemangiopericytomas ^[1][4]. Because they share the same root cause, doctors now understand they are part of the same disease spectrum.

Today, doctors can use a lab test to check for the STAT6 protein in a tumor sample to confidently confirm the diagnosis, whether the tumor is in the brain, the spine, or the chest ^[5][6].

The WHO Reclassifications (2016 and 2021)

In 2016, the World Health Organization (WHO) updated its official classification guidelines to reflect this genetic discovery ^[7]. The WHO officially grouped hemangiopericytoma and solitary fibrous tumor together under one single diagnosis ^[2].

In 2021, the WHO took this a step further and officially retired the term “hemangiopericytoma” entirely, establishing “solitary fibrous tumor” as the single accepted medical name for the condition.

You may still see “hemangiopericytoma” (sometimes abbreviated as HPC) on older pathology reports or in medical portals. This is simply because old terminology takes time to completely phase out of medical use. It does not mean your doctor has made an error or that your diagnosis is outdated.

What This Means for Your Treatment

Because hemangiopericytoma and SFT are the same condition, they are treated using the same overarching medical protocols. Instead of focusing on the historical name of the tumor, your care team will focus on two main things: the tumor location and the tumor grade ^[2][8].

Tumor Grade: Pathologists grade SFTs on a scale from Grade 1 to Grade 3 based on how fast the cells are growing and how aggressive they look under a microscope. Grade 1 tumors are the least aggressive, while Grade 3 tumors are the most aggressive (often matching what used to be called a malignant hemangiopericytoma) ^[2].

Location: While the disease is the same, removing a tumor from the brain or spinal cord carries different risks and requires different surgical specialists (neurosurgeons) compared to a tumor in the chest or abdomen.

The standard of care generally involves trying to safely remove as much of the tumor as possible through surgery ^[8]. For higher-grade tumors, your doctor may also recommend radiation therapy ^[9].

The Importance of Long-Term Monitoring

A critical part of treating SFTs—especially those that are higher grade—is acknowledging their well-documented risk of coming back (recurrence) or spreading to other parts of the body (metastasis) ^[2][8]. This can sometimes happen many years after your initial surgery. Because of this, regular, long-term follow-up imaging (like MRI or CT scans) is a crucial part of your ongoing care to monitor your health.