Polypoid change of the uncinate process.

The uncinate process is a thin, bony leaflet that runs posteroinferior to anterosuperior. It is attached to the perpendicular process of the palatine bone and the ethmoid process of the inferior turbinate inferiorly, and it ascends to the lacrimal bone, skull base, lamina papyracea, and middle turbinate superiorly. [1] The uncinate process forms the medial border of the ethmoid infundibulum, so changes in its mucosal surface can herald the presence of inflammatory disease there, particularly at sites of contact between the uncinate process and the middle turbinate or ethmoid bulla. [2]

The figure (A) demonstrates a polypoid change at the posterior free margin of the right uncinate process, especially at the point of contact with the lateral surface of the middle turbinate.

Polyps arising from the uncinate process or the ethmoid infundibulum may displace the uncinate process itself. The figure (B) illustrates the protrusion of polyps herniating through the middle meatus, displacing both the middle turbinate and the uncinate process. Note the edematous appearance of the mucosal surfaces of the middle turbinate and the uncinate process.

The figure (C) shows polyps filling the middle meatus and displacing the swollen edematous uncinate process anteriorly.

Changes in the uncinate process resulting from polypoid degeneration might complicate the identification of structures along the lateral nasal wall. The figure (D) illustrates an interesting, if not confusing, endoscopic view of the left middle meatus. The middle turbinate is being retracted medially with a suction tip to improve visualization. Edema of the uncinate process at its insertion and its posterior free margin along the lateral nasal wall results in an unusual "double uncinate process" configuration. Note the ethmoid bulla posteriorly.

Because the uncinate process shares a similar pseudostratified columnar epithelial lining with the surrounding nasal cavity, polypoid changes can alter the appearance of structures in the middle meatus. Recognition of this varied appearance of structures along the lateral nasal wall should improve the safety and efficacy of endoscopic sinus surgical procedures.

Polypoid uncinate processes as shown in these cases can best be excised with a microdebrider, which readily reveals hidden pathology in the ethmoid infundibulum by its simultaneous suctioning and cutting actions. C

From the Southern New England Ear, Nose, Throat, and Facial Plastic Surgery Group, New Haven, Conn., and the Section of Otolaryngology, Hospital of St. Raphael, New Haven (Dr. Yanagisawa), and the Section of Otolaryngology, Yale University School of Medicine, New Haven (Dr. Yanagisawa and Dr. Joe).

References

(1.) Stammberger HR, Kennedy DW. Paranasal sinuses: Anatomic terminology and nomenclature. The Anatomic Terminology Group. Ann Otol Rhinol Laryngol Suppl 1995;167:7-16.

(2.) Stammberger H. Functional Endoscopic Sinus Surgery: The Messerklinger Technique. Philadelphia: B.C. Decker, 1991.