Salivary glands
Primary salivary gland neoplasms
Benign
Warthin tumor
Last author update: 1 September 2012
Last staff update: 10 January 2023 (update in progress)
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PubMed Search: Warthin tumor
Table of Contents
Definition / general | Clinical features | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosisCite this page: Handra-Luca A, Hang JF. Warthin tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/salivaryglandswarthin.html. Accessed February 3rd, 2023.
Definition / general
- Common tumor of parotid gland with double layer of epithelial cells resting on dense lymphoid stroma
- Also called papillary cystadenoma lymphomatosum papilliferum, adenolymphoma
- #2 most common benign salivary gland tumor (after pleomorphic adenoma)
Clinical features
- Almost always in parotid gland; 10% of parotid gland tumors
- 70% of bilateral salivary gland tumors are Warthin tumors
- Occasionally in oral cavity, larynx, cervical lymph nodes (Auris Nasus Larynx 2004;31:293)
- Usually male smokers age 40+ years
- Arises from incorporation of lymphoid tissue in parotid gland or induction of cystic and oncocytic changes by inflammatory infiltrate
- Associated with tuberculosis, Brucella mellitensi
- May occur synchronous with pleomorphic adenoma and salivary duct carcinoma
- Malignant change (1%) to lymphoma, Merkel cell carcinoma, adenocarcinoma, NOS, basal cell carcinoma, mucoepidermoid carcinoma, oncocytic carcinoma, salivary duct carcinoma, squamous cell carcinoma, Warthin adenocarcinoma
Treatment
- Surgical excision
- 2% recur after resection
Gross description
- Encapsulated, lobulated, pale gray surface, multicystic with mucinous / serous secretion, 10 - 15% multifocal / bilateral
- 2 - 5 cm
- May be fixed to overlying skin
- May undergo hemorrhagic infarction, particularly after fine needle aspiration
Microscopic (histologic) description
- Double layer of epithelial cells resting on dense lymphoid stroma with variable germinal centers
- Cystic spaces narrowed by polypoid projections of lymphoepithelial elements
- Surface palisading of oncocytic columnar cells with underlying discontinuous basal cells
- Occasional features are cilia, squamous metaplasia associated with infarct-like necrosis, mast cells, dendritic cells, mucin secreting cells, sebaceous cells
- Very rarely signet ring cells
- No myoepithelial component
Microscopic (histologic) images
Cytology description
- Squamous appearance of degenerated oncocytes
- Sheets of oncocytes and mixed population of lymphocytes in a characteristic dirty proteinaceous background
- Oncocytic sheets show an organized honeycombing or papillary arrangement and are typically cyanophilic at the periphery and bright orange at the center on Papanicolaou stain
- Oncocytes show densely granular cytoplasm, centrally located nuclei and small nucleoli
- Lymphocytes are mostly small mature cells
Cytology images
Contributed by Robin Pike, M.D. and Jen-Fan Hang, M.D.
Oncocytic cells in lymphoid background
Finely granular cytoplasm of oncocytic cells
"Junky" cystic background
Oncocytic and lymphoid cells
Oncocytic and lymphoid cells, cyst contents
Oncocytic cells with squamous features
Dirty background
Fragment of oncocytes
Dense cytoplasm
Bilayered epithelium
Positive stains
Negative stains
- Amylase, vimentin, desmin, smooth muscle actin, EBV, HHV8
Electron microscopy description
- Oncocytes are stuffed with mitochondria with cup shapes or concentric ring forms but no partitions
Molecular / cytogenetics description
- Not clonal (Hum Pathol 2000;31:1377, Mod Pathol 2005;18:964), although cases with coexisting mucoepidermoid carcinoma are associated with t(11;19) and the CRTC1 / MAML2 fusion transcript (Genes Chromosomes Cancer 2008;47:309)
- Diploid, t(11,19), HHV8 DNA may be positive
Differential diagnosis
- Acinic cell carcinoma
- Squamous cell carcinoma: may resemble at fine needle aspiration
