Pathogenesis of sialadenosis: possible role of functionally deficient myoepithelial cells.
OBJECTIVE
The pathogenesis of acinar enlargement in sialadenosis is obscure. As myoepithelial cells had been reported to show degenerative changes, we decided to investigate the possible role of functionally deficient myoepithelial cells in the development of sialadenosis.


METHODS
This study was a morphometric analysis of glands immunohistochemically stained for CK14, alpha-actin, and Ki67 in 10 cases of sialadenosis and 11 normal parotids.


RESULTS
In sialadenosis, acini were much larger; there was a minor decrease in the density of the distribution of myoepithelial cells stained for CK14 and a major decrease in the density of the distribution and thickness of the myofilament component of myoepithelial cells stained for alpha-actin; and the proliferation of acinar and myoepithelial cells was reduced.


CONCLUSIONS
Our results demonstrate a major loss and thinning of the myofilament component of the myoepithelial cells and thereby a loss of mechanical support for the acini in sialadenosis. This possibly allows acinar cells to expand as secretory granules accumulate intracellularly to produce the great acinar enlargement. This functional myoepithelial insufficiency is possibly a consequence of an autonomic neuropathy secondary to severe metabolic or hormonal disorders.
Ihrler
Stephan
S
Institute of Pathology, Ludwig Maximilian University, Munich, Germany.
Rath
Christian
C
Zengel
Pamela
P
Kirchner
Thomas
T
Harrison
John D
JD
Weiler
Christoph
C
D008841:Actin Cytoskeleton / Q000473:pathology; D000199:Actins / Q000032:analysis; D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000150:complications*; D016022:Case-Control Studies; D004847:Epithelial Cells / Q000473:pathology / Q000502:physiology; D005260:Female; D006801:Humans; D053547:Keratin-14 / Q000032:analysis; D019394:Ki-67 Antigen; D008297:Male; D008875:Middle Aged; D032342:Muscle Cells / Q000473:pathology / Q000502:physiology; D010305:Parotid Diseases / Q000209:etiology* / Q000473:pathology*; D022142:Secretory Vesicles / Q000473:pathology
D000199:Actins; D053547:Keratin-14; D019394:Ki-67 Antigen