Chronic Sclerosing Sialadenitis

Bruce M. Wenig, MD

Key Facts

Terminology

Chronic fibroinflammatory salivary gland disease with characteristic morphology that may represent IgG4-associated disease

Etiology/Pathogenesis

Increasing evidence that CSS, if IgG4 related, may be component of IgG4-related systemic disease
Prior to IgG4 association, sialolithiasis felt to be commonly associated with CSS of submandibular gland
- May be true in percentage of non-IgG4-related cases

Clinical Issues

Primarily affects submandibular gland
IgG4-related sialadenitis steroid sensitive

Microscopic Pathology

Preservation of lobular architecture
Dense lymphoplasmacytic infiltrate within lobules
Large irregular lymphoid follicles with expanded geographic germinal centers
Sheets of mature plasma cells
Acinar atrophy
Lobules separated by fibrosis composed of fibroblasts and chronic inflammatory cells
Phlebitis (obliterative or nonobliterative) may or may not be identified

Ancillary Tests

Abundant IgG4(+) plasma cells present
IgG4(+) plasma cells present in inflamed lobules, interlobular septae, occasionally in germinal centers

Submandibular chronic sclerosing sialadenitis is characterized by retention of the lobular architecture, dense inflammatory infiltrate, acinar atrophy, and interlobular fibrosis.

It is now recognized that submandibular chronic sclerosing sialadenitis may be an IgG4-related disease, confirmed by the presence of abundant IgG4 immunoreactive plasma cells

TERMINOLOGY

Abbreviations

Chronic sclerosing sialadenitis (CSS)

Synonyms

Küttner tumor
IgG4-associated sialadenitis
Punctate parotitis

Definitions

Chronic fibroinflammatory salivary gland disease with characteristic morphology that may represent IgG4- associated disease

ETIOLOGY/PATHOGENESIS

Immune-Mediated

Increasing evidence that CSS, if IgG4 related, may be component of IgG4-related systemic disease
- IgG4-related diseases include
  - Autoimmune pancreatitis
  - Involvement of extrapancreatic organs including kidney, lung, retroperitoneum, liver, gallbladder, lymph nodes, breast, salivary glands, lacrimal gland, aorta
- Morphologic features in CSS suggesting immune-mediated process include
  - Presence of prominent lymphoplasmacytic infiltrate and lymphoid follicles
  - Presence of unusual cytotoxic T-cell populations

Obstructive Sialadenitis

Prior to IgG4 association, sialolithiasis felt to be commonly associated with CSS of submandibular gland
- May be true in percentage of non-IgG4-related cases

CLINICAL ISSUES

Epidemiology

Incidence
- Unknown, but under recognized
Age
- Most often occurs in 4th to 7th decades
Gender
- Affects males slightly more often than females

Site

Primarily affects submandibular gland
- Rarely, multiple salivary glands (major and minor) may be affected in single patient

Presentation

Pain and swelling of affected gland common
- Often associated with ingestion of food
Patients may present with asymptomatic swelling of affected gland
May be localized to salivary gland involvement
May be associated with sclerosing lesions in extrasalivary gland tissues (systemic IgG4-related disease)

Laboratory Tests

Serum IgG4, IgG, IgG4/IgG ratio (normally 3-6%) typically elevated
Antibodies present in Sjögren syndrome including anti-SS-A, anti-SS-B not found in CSS
Absence of antineutrophilic antibodies (cytoplasmic and perinuclear)
Eosinophilia, hypergammaglobulinemia, and antinuclear antibodies (ANA) may be present in systemic but not localized disease

Treatment

Options, risks, complications
- IgG4-related sialadenitis steroid sensitive
Surgical approaches
- CSS associated with sialolithiasis
  - Removal of stone by surgery, endoscopy or lithotripsy
  - In approximately 20% of cases, symptoms persist, necessitating surgical resection of involved gland

Prognosis

IgG4-related
- Excellent response to steroid
Sialolithiasis-related
- Removal of stone results in reduction in swelling and pain
Rarely, extranodal marginal zone B-cell lymphoma (MALT) of salivary gland and salivary duct carcinoma may arise in background of CSS

IMAGE FINDINGS

Radiographic Findings