en Otorhinolaryngology Otorhinolaryngology Original Research Original Research This study evaluated the histopathologic changes in the round window niche. , and membrane in cases of chronic suppurative otitis media. The pathologic process was found in all subjects. Fibrocystic or fibrous tissue was most commonly seen, while active granulation was less developed. The round window membrane was thicker and inflamed throughout its layers. Inflammatory invasion of the inner ear through the membrane: is very rare, because the thickened membrane has a protective role for spreading of infection. Round window niche, Membrane, Chronic suppurative otitis media. 111 113 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-403&slc_lang=en&sid=1 DRAGOSLAVA R. DJERIC 20031947532846004642 20031947532846004642 Yes From the Institute of Otorhinolaryngology and Maxillofacial Surgery, Belgrade, Yugoslavia