posterior naris

Sphenochoanal polyps are rare, benign, solitary masses that arise from the sphenoid sinus, exit through the sphenoid ostium, pass across the sphenoethmoid recess, and extend into the choana.

5 lateral wall 8 Right ethmoid sinus, right lamina No 6 papyracea, and posterior choana 9 Left lateral wall, anterior and No 6 posterior ethmoid sinuses, and left sphenoid sinus

Endoscopic examination detected a septal deviation to the right and a gray mass that filled the left posterior choana and extended across the nasopharynx to the right side.

Both polyps originated in the middle meatus and obstructed the osteomeatal complex, and the mass on the right extended to the choana.

However, nasal endoscopy revealed that a large polypoid mass had filled the fight superior nasal cavity and extended into the posterior choana (figure 1).

The route of entry is usually anterior, although some foreign bodies have been reported to have entered through the choana during vomiting or coughing.

Choanal polyps are benign masses that protrude through the choana into the nasopharynx.

Axial CT showed that the nasopharyngeal mass had arisen from the posterior portion of the choana on the right side (figure 2, B).

Endoscopic examination could not be performed through the narrow side, but flexible fiberoptic endoscopy through the right nasal cavity detected a polypoid mass emanating from the left choana.

In some cases, a polyp may extend posteriorly into the choana or the nasopharynx and present as an antrochoanal polyp.

Computed tomography (CT) of the sinuses revealed that an expansile soft-tissue mass had filled the right nasal cavity and extended back to the choana and forward to the nares (figure 2).