Chronic rhinosinusitis

by Jason Wasserman MD PhD FRCPC
March 19, 2022

What is chronic rhinosinusitis?

Chronic rhinosinusitis is a medical condition caused by inflammation of the nasal cavity and paranasal sinuses. Chronic rhinosinusitis can be caused by anything that leads to chronic inflammation of the nasal cavity and paranasal sinuses including allergies, upper respiratory tract infections, smoking, cystic fibrosis, exposure to irritants, aspirin intolerance, and autoimmune diseases. People with chronic rhinosinusitis are more likely to develop a type of non-cancerous growth in the nasal cavity or paranasal sinuses called a sinonasal inflammatory polyp.

How do pathologists make the diagnosis of chronic rhinosinusitis?

The diagnosis of chronic rhinosinusitis is usually made after a small tissue sample is removed in a procedure called a biopsy. The tissue is then examined under the microscope by a pathologist.

What does chronic rhinosinusitis look like under the microscope?

When examined under the microscope, the tissue sample is usually made up of multiple pieces of sinonasal mucosa. Large numbers of specialized inflammatory cells including neutrophils, eosinophils, plasma cells, and lymphocytes are typically seen within the stroma. Pathologists sometimes use the term chronic allergic rhinosinusitis when most of the inflammatory cells within the stroma are eosinophils. The stroma also tends to look white under the microscope because it is full of fluid. This type of change is called edema. Inflammatory cells such as neutrophils and eosinophils may also be seen in the epithelium on the surface of the tissue. When these same features are seen in a growth that sticks out from the surface of the tissue, it is called a sinonasal inflammatory polyp.

chronic rhinosinusitis

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