Figure 1: Representative histological findings of ankylotic and normal stapes footplates (H&E). (a) Obliterative otosclerosis with high activity at the anterior pole of the stapes footplate. Hypercellularity and increased numbers of osteoclasts should be noted. “Swiss cheese” pattern of pseudovascular spaces is marked by the white arrow. (b) Inactive otosclerotic focus at the anterior pole of the stapes footplate. Hypocellularity, hypovascularization, marked basophilia, and woven pattern of cement lines can be considered. (c) Hemosiderosis with pathological bone remodeling and active eosinophilic staining. The osteocytes of the stapes footplate are absent and are replaced by hemosiderophages containing dark hemosiderin granules. (d) Annular calcification with decreased cellularity and vascularization. The stapes footplate shows a marked thickening and an angled, bulky posterior pole (black arrow). (e) Histological representation of a normal stapes. Abbreviations: AP: anterior pole; PP: posterior pole; AC: anterior crus; PC: posterior crus; FP: footplate.