Salivary glands
Inflammatory
Lymphoepithelial sialadenitis

Editor-in-Chief: Debra L. Zynger, M.D.

Minor changes: 3 November 2020

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PubMed Search: lymphoepithelial sialadenitis

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Cite this page: Ely K. Lymphoepithelial sialadenitis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/salivaryglandslymphoepithelialsialadenitis.html. Accessed November 23rd, 2020.
Definition / general
  • Part of a heterogeneous group of lesions with a prominent lymphoid component that involves the salivary glands (Med Oral Patol Oral Cir Bucal 2007;12:E479)
  • May be isolated or associated with Sjögren syndrome
  • Histologically characterized by the lymphoepithelial lesion, which is formed by a proliferation of ductal remnants permeated by lymphocytes (Virchows Arch 1999;434:315)
Essential features
  • May be isolated or associated with Sjögren syndrome
  • Usually occurs in women
  • Affects the parotid (90%) and submandibular gland (10 - 15%) with rare involvement of the minor salivary glands
  • Histologically characterized by the lymphoepithelial lesion, which is formed by a proliferation of ductal remnants permeated by lymphocytes
  • Indolent behavior; however, continued observation is mandatory because of an increased risk for lymphoma development (MALT lymphoma)
Terminology
  • Myoepithelial sialadenitis: a misnomer as ultrastructural and immunohistochemical studies showed that the cells involved are not myoepithelial cells but rather basal epithelial cells (Virchows Arch 1999;434:315)
  • Autoimmune sialadenitis
  • Lymphoepithelial lesion
  • Sjögren sialadenitis
ICD coding
  • ICD-10: K11.2 - sialoadenitis
Epidemiology
Sites
  • Affects the parotid (90%) and submandibular gland (10 - 15%) with rare involvement of the minor salivary glands (Ellis: Tumors of the Salivary Glands, 3rd Series, 1996)
    • Commonly bilateral
    • If the submandibular gland is affected in patients with Sjögren syndrome, the parotid glands are usually also involved
Etiology
  • Cause of lymphoepithelial sialadenitis unassociated with Sjögren syndrome has not been determined (Chin Med J (Engl) 2015;128:493)
  • Lymphoepithelial sialadenitis in the setting of Sjögren syndrome is likely multifactorial, with environmental and genetic factors causing an abnormal autoimmune response (Pathol Int 2008;58:465)
Clinical features
Diagnosis
  • American College of Rheumatology classification criteria for Sjögren syndrome for patients with signs and symptoms that may be suggestive of Sjögren syndrome require 2 of the following 3:
    • Positive serum anti SSA or anti SSB (positive rheumatoid factor and antinuclear antibody titer > 1:320)
    • Ocular staining score ≥ 3
    • Presence of focal lymphocytic sialadenitis with a focus score ≥ 1 focus/4 mm² in labial salivary gland biopsy samples (Arthritis Care Res (Hoboken) 2012;64:475)
Laboratory
  • Positive serum anti SSA, anti SSB or a positive rheumatoid factor and antinuclear antibody titer of 1:320 are present when associated with Sjögren syndrome (Med Clin North Am 2014;98:1407)
Prognostic factors
Case reports
Treatment
Microscopic (histologic) description
  • Major salivary gland:
    • Early, extent of inflammation varies with collections of small lymphocytes surrounding intralobular ducts, minimal epitheliotropism, plasma cells not prominent (Med Oral Patol Oral Cir Bucal 2007;12:E479)
    • Inflammation intensifies, contains lymphoid follicles with germinal center formation and more frequent plasma cells
    • As inflammation becomes diffuse, there is partial and then total acinar destruction with the only remaining epithelium being the ducts
    • Remnant ducts proliferate and are infiltrated by lymphocytes, forming the lymphoepithelial lesion
      • Eosinophilic, hyaline basement membrane-like material may be present among the cells of the lesion (Virchows Arch 2003;443:17)
    • Overall lobular architecture is maintained
  • Labial salivary gland:
    • Adequate biopsy has a glandular area of at least 4 mm², optimally 10 mm² (Arthritis Rheum 2011;63:2021)
    • A focus score ≥ 1 is strongly associated with Sjögren syndrome
      • A focus is defined as a collection of lymphocytes numbering > 50 lymphocytes/4 mm² of salivary gland tissue
    • Germinal centers and lymphoepithelial lesions are less common in lip biopsies
Microscopic (histologic) images

Contributed by James S. Lewis, M.D.
Maintenance of lobular architecture

Maintenance of lobular architecture

Intense chronic inflammation

Intense chronic inflammation

Plasma cells

Plasma cells

Lymphoepithelial lesion

Lymphoepithelial lesion

Positive stains
Negative stains
  • SMA negative within lymphoepithelial lesion
Sample pathology report
  • Parotid, left, excision:
    • Lymphoepithelial sialadenitis (see comment)
    • Comment: There is extensive chronic inflammation with plasma cells and lymphocytes containing follicles with germinal centers. The infiltrate effaces the parenchyma, resulting in acinar loss. Residual ducts show hyperplasia of their lining as well as permeation by lymphocytes. These glandular complexes represent the lymphoepithelial lesion.
Differential diagnosis
Board review style question #1

    A 40 year old woman complaining of xerostomia, dry eyes and bilateral salivary gland enlargement undergoes excision of her parotid. After receipt of the pathologic diagnosis, her clinician tells her that she is at increased risk for which of the following?

  1. Burkitt lymphoma
  2. Hodgkin lymphoma
  3. Extranodal marginal zone B cell lymphoma
  4. Anaplastic large cell lymphoma
Board review answer #1
C. Extranodal marginal zone B cell lymphoma. The patient has lymphoepithelial sialadenitis.

Comment Here

Reference: Lymphoepithelial sialadenitis
Board review style question #2

    Which of the following is true about lymphoepithelial sialadenitis?

  1. It is composed of myoepithelial cells, hence the name myoepithelial sialadenitis is an appropriate alternative term for this lesion
  2. It may be isolated or associated with Sjögren syndrome
  3. It affects women and men equally
  4. It involves the submandibular gland most commonly, followed by the minor salivary glands
Board review answer #2
B. It may be isolated or associated with Sjögren syndrome

Comment Here

Reference: Lymphoepithelial sialadenitis
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