Monday 5 November 2007
LESA, myoepithelial sialadenitis, MESA, salivary benign lymphoepithelial lesion,
Definition: LESA is found in virtually all patients with Sjögren’s syndrome but may occur without Sjogren’s syndrome. It is associated with lymphoid infiltration of salivary gland tissue, producing atrophy and destruction of the acini.
Myoepithelial sialadenitis of the salivary gland is associated with an increased risk of lymphoma, but criteria that predict its development have not been clearly defined.
Lymphoepithelial lesions form as the result of atrophy of the columnar ductal epithelium and proliferation of basal epithelial cells, associated with intraepithelial infiltration of marginal zone B cells. These are analogous to the lymphoepithelial lesions seen in gastrointestinal cases of extranodal marginal zone lymphoma.
Reactive lymphoid follicles typically surround the altered ducts, and aggregates of marginal zone B cells may be present around affected ducts as well as around reactive follicles.
Acute sialodochitis and fibrosis are not typical features of LESA. The development of frank lymphoma is characterized by broad sheets of marginal zone cells outside of follicles and lymphoepithelial lesions.
salivary benign lymphoepithelial lesions (BLELs)
- chronic sialadenitis
- lymphocytic sialadenitis
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