Prolapsed Antral Mucosa: Variant of Maxillary Sinus Mucocele

Lee, Kyung Chul; Lee, Seong Chae

Abstract

BACKGROUND AND OBJECTIVES: An array of diseases may cause masses in the maxillary sinus. Among the various diseases, the prolapsed antral mucosa (PAM) presents an inflammed, swollen maxillary antral mucosa which becomes redundant and prolapsed into the nasal cavity through a widened natural ostium, mimicking an antrochoanal polyp. The purposes of this study were to introduce prolapsed antral mucosa and evaluate the differences between prolapsed antral mucosa and other diseases, particularly maxillary sinus mucocele.
MATERIALS AND METHODS
We retrospectively analyzed 18 patients who were diagnosed with prolapsed antral mucosa at the Kangbuk Samsung Hospital between 1990 and 1998. The presenting signs and symptoms, endoscopic finding, radiological finding, histopathological finding were reviewed.
RESULTS
Of the symptoms reported by patients in this study, nasal obstruction was the most frequent, followed by rhinorrhea, postnasal drip, foul odor and headache. Endoscopic findings showed protruding maxitlary antral mucosa into the middle meatus. On the CT, the prolapsed antral mucosa presented features such similar to antrochoanal polyp as unilateral and homogeneous soft tissue density which extended into the middle meatus. MR imaging was useful for differentiating the prolapsed antral mucosa from neoplasms and antrochoanal polyp. Prolapsed antral mucosa and maxilla sinus mucocele showed the same histopathological features such as epithelial lining of columnar or metaplastic squamous cells with varying glandular structures, and dense fibrous stroma intiltrated by infiammatory cells.
CONCLUSIONS
The prolapsed antral mucosa is considered as a variant of maxillary sinus mucocele. History, physical examination, biopsy, CT and MM are useful for differentiating the prolapsed antral mucosa from other diseases. Although a prolapsed antral mucosa is rare, it should be considered in the diagnosis and the treatment of unilateral maxillary sinus lesion.