Salivary glands

Topic Completed: 1 September 2015

Minor changes: 3 June 2020

Copyright: 2002-2020,, Inc.

PubMed Search: Sialadenitis[TI] salivary[TI]

Sally Tanakchi, M.D.
F. Zahra Aly, M.D., Ph.D.
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Cite this page: Tanakchi S, Aly FZ. Sialadenitis-infectious. website. Accessed July 13th, 2020.
Definition / general
  • Bacterial, viral or autoimmune

  • Bacterial sialadenitis:
    • Rare, usually due to ascending infection of ductal system by Staphylococcus aureus, Streptococcus viridans or gram negative bacteria
    • Predisposing factors include obstructive lesions such as sialolithiasis, dehydration, malnutrition or immunosuppression
    • Usually presents with unilateral painful enlargement of salivary gland
    • May cause abscess requiring surgical drainage

  • Chronic sialadenitis:
    • Also called lymphoepithelial sialadenitis (LESA)
    • Relatively common
    • Chronic lymphocytic inflammation, often without symptoms
    • Associated with obstruction (with atrophy and fibrosis), rheumatoid arthritis (older women), Sjögren syndrome, sialolithiasis, mumps
    • 50% are monoclonal by PCR but MALT lymphoma has ducts surrounded by broad coronas of monocytoid cells, infiltration of interfollicular region by monocytoid cells or atypical plasma cells containing Dutcher bodies, monoclonality by immunohistochemistry or flow cytometry, monocytoid infiltrates in regional lymph nodes (Mod Pathol 2002;15:255)
    • Micro: markedly hyperplastic lymphoid infiltrates with loss of salivary gland acini; ducts are surrounded by and infiltrated by lymphoid cells

  • Chronic sclerosing sialadenitis:
    • General:
      • Included in the spectrum of IgG4 related sclerosing diseases
      • Most patients are male and over 50 years (in contrast to Sjögren syndrome)
      • Associated in 40% of cases with history of allergic disease such as bronchial asthma or chronic sinusitis (Arthritis Rheum 2012;64:3061)
      • Serum IgG4 concentration is dramatically elevated in many patients but may be normal in up to 40%
    • Micro:
      • Characterized by presence of three major criteria: dense lymphoplasmacytic infiltrate, storiform pattern of fibrosis and obliterative phlebitis
      • Minor criteria are phlebitis without obliteration of the lumen and increased numbers of eosinophils
      • In the absence of less than two of the major criteria, elevated tissue IgG4:
        • IgG ratio (> 40%) or elevated serum IgG4 (> 135 mg/dl) may corroborate diagnosis
      • Two features that are relatively inconsistent with the diagnosis of IgG4 related disease are the presence of epithelioid cell granulomas and a prominent neutrophilic infiltrate

  • Sclerosing polycystic sialadenitis:
    • General:
      • Rare tumorous condition predominantly affecting the parotid gland (80% of cases)
      • In some cases, may be considered a neoplasm due to monoclonal nature of the lesion
      • May recur after resection (20%) due to multifocal disease / incomplete resection
      • Generally not associated with malignant transformation
    • Gross:
      • Sharply circumscribed, variable encapsulation
    • Micro:
      • Histologically resembles sclerosing adenosis / fibrocystic change of breast.
      • Composed of acini and ductal elements embedded in densely sclerotic stroma
      • Characteristic finding is presence of large acinar cells with abundant eosinophilic cytoplasmic granules
      • May exhibit ductal epithelial proliferation ranging from hyperplasia, atypia to DCIS-like
      • The stroma may show focal adipose tissue, myxoid change, variable radial scar
      • Immunohistochemical studies are of limited value
      • Ductal and acinar components are 1 - 2% positive for Ki67 with consistent but variable expression of ER and PR
      • CEA, p53 and HER2 are negative
    • Differential diagnosis:
      • Highly characteristic histological features exclude all other considerations
      • Cytologically difficult to diagnose due to rarity of condition and presence of variable cell types in a cystic background
Microscopic (histologic) images

Images hosted on other servers:

Sclerosing polycystic adenosis:
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Round to oval, circumscribed borders

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Foamy vacuolated,
apocrine, clear,
oncocyte-like cells

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Highly characteristic

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Variably prominent, dilated ductal

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Dense, sclerotic collagen

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Stromal distortion

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