NCI Dictionary of Cancer Terms

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The NCI Dictionary of Cancer Terms features 7,777 terms related to cancer and medicine.

Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.

frontal sinus
(FRUN-tul SY-nus)
A type of paranasal sinus (a hollow space in the bones around the nose). There are two, large frontal sinuses in the frontal bone, which forms the lower part of the forehead and reaches over the eye sockets and eyebrows. The frontal sinuses are lined with cells that make mucus to keep the nose from drying out.

EnlargeAnatomy of the paranasal sinuses; drawing shows front and side views of the frontal sinus, ethmoid sinus, maxillary sinus, and sphenoid sinus. The nasal cavity and pharynx (throat) are also shown.

Anatomy of the paranasal sinuses (spaces between the bones around the nose).