RESUMEN
An enlarged pneumatized middle turbinate, termed "concha bullosa" is a relatively common anatomical variant. It may be the site of inflammatory disease ranging from simple mucosal thickening to a mucocele. But a conchal mucocele is a rare disease such as mucoceles of the posterior ethmoid and sphenoid sinus. The mucociliary transport within a concha bullosa is usually toward the conchal ostium located on the anterosuperior aspect of the middle turbinate and in most cases it opens into the frontal recess. Chronic obstruction of a conchal ostium can lead to a mucocele. Chronic pressure within the mucocele can cause the walls of the middle turbinate to expand, further destructing bulla, other ethmoid cells, and lamina papyracea. Authors have experienced one case of a conchal mucocele with anterior ethmoid and frontal recess extension which presented with exophthalmos. We performed functional endoscopic sinus surgery. Postoperatively, exophthalmos was spontaneously corrected.