Nasopharyngeal angiofibroma

by Jason Wasserman MD PhD FRCPC
July 17, 2024

Background:

Nasopharyngeal angiofibroma is a locally aggressive but benign tumour originating in the nasal cavity or nasopharynx. It exclusively affects males. Alternative names for this tumour include juvenile angiofibroma and sinonasal angiofibroma.

What are the symptoms of nasopharyngeal angiofibroma?

The symptoms of nasopharyngeal angiofibroma include recurring nosebleeds and nasal congestion, while more extensive tumours may induce facial deformities, alterations or loss of vision, and pain.

What causes nasopharyngeal angiofibroma?

While the precise cause of nasopharyngeal angiofibroma remains incompletely understood, most tumours exhibit a genetic alteration involving the CTNNB1 gene, leading to abnormal activity in the WNT molecular pathway. Additionally, the growth of these tumours seems influenced by the hormone androgen, which explains the male predominance post-puberty. Those with familial adenomatous polyposis (FAP) syndrome face an elevated risk of developing this tumour.

Is nasopharyngeal angiofibroma benign or malignant?

Nasopharyngeal angiofibroma is a benign but locally aggressive tumour. As a benign tumour, it will not metastasize (spread to distant body parts). However, its aggressive growth can damage structures surrounding the tumour. Therefore, careful management and treatment are essential to address the symptoms and prevent complications.

Microscopic features of this tumour

Under microscopic examination, nasopharyngeal angiofibroma comprises numerous irregular, variably sized blood vessels surrounded by supporting cells called fibroblasts. The fibroblasts may be described as bipolar (having two ends) or stellate (star-shaped), and occasional mitotic figures (dividing cells) may be seen. The connective tissue within the tumour may be described as collagenized or fibrotic. Some of the blood vessels may contain foreign material and there may be areas of necrosis (cell death) if a procedure called an embolization was performed before the tumour was surgically removed.

What other tests may be performed to confirm the diagnosis?

Pathologists often perform immunohistochemistry (IHC) to confirm the diagnosis. This test identifies specific cell types based on their expressed proteins. Tumour cells in nasopharyngeal angiofibroma typically exhibit nuclear expression of beta-catenin and the androgen receptor, while markers such as S100, SOX-10, and STAT6 should be negative (not expressed).

​Margins

A margin is the normal tissue surrounding a tumour and is removed with the tumour at the time of surgery. A margin is considered ‘positive’ when the tumour cells are seen at the cut edge of the tissue. Because nasopharyngeal angiofibroma is a non-cancerous tumour, the report may simply state that the tumour was completely excised or that margins are negative. Margins are only described in your report after the entire tumour has been removed.

Can this tumour come back after surgery?

Yes. If the tumour is not removed completely, regrowth (recurrence) can occur. Negative surgical resection margins reduce the chance of regrowth.

About this article

Doctors wrote this article to help you read and understand your pathology report for nasopharyngeal angiofibroma. Contact us with any questions about this article or your pathology report.

Other helpful resources

Atlas of Pathology