During review of a coronal CT scan before endoscopic surgery, a radiologist identifies an ethmoid air cell located inferolaterally along the floor of the orbit, projecting into the roof of the maxillary sinus and narrowing the maxillary sinus ostium. This cell is called:

• A Agger nasi cell
• B Haller cell (infraorbital ethmoid cell) ✓
• C Onodi cell
• D Frontal bulla

Explanation

A Haller cell is an anterior ethmoid air cell that pneumatizes along the medial floor of the orbit into the roof of the maxillary sinus. When large, it narrows the infundibulum and maxillary ostium, predisposing to recurrent maxillary sinusitis. An agger nasi cell lies anterior to the frontal recess, an Onodi cell lies superior and lateral to the sphenoid near the optic nerve, and the frontal bulla is a cell within the frontal recess itself.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.