Giant antrochoanal polyp: MRI findings.

Antrochoanal polyps are rare inflammatory lesions that arise in the lumen of the maxillary sinus; they herniate through the major or accessory ostium into the nasal cavity and extend into the choanal area. (1) They usually appear in children and young adults (figure).

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The primary symptoms of antrochoanal polyps are nasal obstruction, rhinorrhea, epistaxis, postnasal drip, and snoring. (2) Various surgical approaches have been used in the treatment of these entities, including endoscopic polypectomy and meatal antrostomy, which have been reported to be effective. (2)

Imaging generally demonstrates a dumbbell-shaped lesion that fills the maxillary antrum; the lesion spills through the enlarged maxillary ostium and infundibulum into an enlarged middle meatus and nasal cavity. Large polyps can reach the nasopharyngeal airway. Although computed tomography manifestations are well known, MRI reports are scarce. (3)

References

(1.) Hamsberger HR, Wiggins RH, Hudgins PA, et al. Sinonasal solitary polyps. In: Hamsberger HR, Wiggins RH, Hudgins PA, et al, eds. Diagnostic Imaging: Head and Neck. 1st ed. Salt Lake City: Amirsys, 2004; sect 112:50.

(2.) Gendeh BS, Long YT, Misiran K. Antrochoanal polyps: Clinical presentation and the role of power endoscopic polypectomy. Asian J Surg 2004;27:22-5.

(3.) Chung SK, Chang BC, Dhong HJ. Surgical, radiologic, and histologic findings of the antrochoanal polyp. Am J Rhinol 2002;16:71-6.

From the Department of Radiology, Louisiana State University Health Sciences Center, New Orleans.