耳硬化症.ppt

Otosclerosis
2015-7-31
Otosclerosis
Otosclerosis is a disorder of the bony labyrinth and stapes affecting only humans.
In 1735, the Italian anatomist and surgeon Antonio Maria Valsalva of Bologna was the first to report on the lesion
Introduction
Autosomal dominant :plete rance
Male : Female = 1 : 2
Peak incidence in the second or third decade
60% with family history
10% of Caucasians with histologic findings, 12% have clinical symptoms.
One ear is affected, the other is involved 80%
Primarily conductive hearing loss, may be a sensorineural or mixed hearing loss
Embryology
At 8 weeks, the cartilaginous framework is begun. At 16 weeks, endochondral bony replacement of this framework.
The fissula ante fenestram, anterior to oval window is the last area of endochondral bone formation.
This region is affected in 80~90% of patients
Histopathology
A: Active (Grade I) otosclerosis. Hypercellularity, intense basophilic staining and pseudo-vascular spaces filled by multinucleated osteoclasts and hyaline (white arrow) can be seen.
Histopathology
B: Otosclerosis with moderate activity (Grade II). The pseudo-vascular spaces are widened and empty (white arrow). There is a marked thickening of the stapes footplate. The osteoid substance shows marked basophilia with hypercellularity.
Histopathology
C: Inactive (Grade III) substance shows eosinophilic staining and sparsely located osteocytes.
Histopathology
D: Burned out (Grade IV) otosclerotic focus with intense
eosinophilic staining and acellular osteoid substance (white arrow).
Otosclerosis-associated genes
Although these loci have been mapped, we have little information regarding the role of these genes in disease development
Immunohistologic research