General Medical Information

Clinical Significance of Mucosal Thickening

Barbara A. Zeifer

Making a diagnosis from the finding of mucosal thickening on CT scans and MR images without clinical information can be hazardous. The presence of incidental abnormalities of the ethmoidal sinuses when there is no history of allergic or inflammatory sinusitis is significant. Some degree of ethmoidal disease occurs among nearly 11% of patients undergoing CT of the head for unrelated problems. Most of these patients have focal disease localized to four or fewer ethmoid air cells. Magnetic resonance images frequently show clinically insignificant mucosal thickening as well. This mucosal thickening is not histologically specific. It can represent acutely edematous mucosa, chronically hypertrophic mucosa, or granulation tissue. If the patient does not have symptoms, such findings have no adverse consequences.

The anatomic configuration of the sphenoidal sinus and its neurovascular relations raise a different set of issues. The optic nerve, cavernous sinus, and orbital apex are at risk in the presence of sphenoidal sinusitis. Incidental sphenoidal sinusitis is not as common as incidental ethmoidal disease. When sphenoidal sinusitis is identified on an imaging study, the risk of optic complications should be considered. Nearly 25% of patients with severe sphenoidal sinusitis have serious neuroophthalmic dysfunction.