medwireNews: A long-term analysis of a large intraspinal hemangiopericytoma (HPC) patient cohort to date finds that survival and tumor recurrence is significantly associated with the pathologic grade of the cancer and not its location or degree of resection.
By relating more aggressive tumor grades to higher recurrence and mortality rates, the retrospective analysis adds to the scarce literature addressing the clinical profile, management, and outcomes of patients with intraspinal HPC.
Compared with World Health Organization (WHO) grade II tumors, patients with the most severe grade III lesions exhibited a survival time that was 8 years shorter and a 6.4-year earlier recurrence. Neither survival or recurrence were significantly affected by total or subtotal resection, patient age and gender, and tumor classification.
Surgical removal and postoperative radiotherapy are crucial for treating this rare, malignant form of extraxial tumor, according to the Neurosurgery study. Out of 26 patients with ages ranging from 2 to 73 years, 54% achieved total resection while 85% received postoperative radiotherapy; 76.0% survived for 5 years, while 29.4% remained recurrence free.
"However," write Huan-guang Liu (Capital Medical University, Beijing, China) and colleagues, "total resection may not be necessary for these tumors. Stereotaxic radiosurgery may be a good alternative to control the recurrent lesions."
The study authors also introduced a classification system based on morphologic data, which divided intraspinal HPCs into three types and five subtypes based on location: extradural, intradural, and intra- to extradural and paravertebral.
The team encountered difficulty in distinguishing intraspinal HPC from other types of tumor and reported low diagnostic success from preoperative imaging. The I and IIA subtypes were often confused with spinal meningiomas and schwannomas, while the IIB subtype often got mixed up with ependymomas and hemangioblastomas.
Overall, the authors consider an assessment of HPC pathologic features as vital to making accurate diagnosis when loss of architecture along with enhanced cellularity, nuclear polymorphism, mitosis, and necrosis is consistently observed.
All HPC tumors in the study tested positive for vimentin staining, which - as a marker of mesenchymal tissue - corroborates with HPCs origin stemming from mesenchymal tissue. This trait, as well as testing negative for epithelial membrane antigen, allows the differentiation between HPCs and meningiomas.
In an accompanying comment, Dean Chou (University of California, San Francisco, USA) questions radiation therapy's impact on survival and advises stereotactic radiosurgery as another option. But overall, he writes, "this article may ultimately prove to be a useful tool to implement evidence-based management of [HPCs]."
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