1. Salivary Gland Pathology
Thomas Rosenzweig, MD

3. Xerostomia
Xerostomia is defined as a dry mouth resulting from a decrease in the production of saliva
Seen in Sjögren syndrome
Sialadenitis of the salivary glands is also seen
Involvement of the lacrimal glands in Sjögren syndrome may also produce dry eyes—keratoconjunctivitis sicca.
Seen in radiation therapy

4. Sialadenitis (salivary gland inflammation)
Mucoceles
most common inflammatory salivary gland lesion
lower lip
Trauma causes blockage or rupture of a salivary gland duct, with leakage of saliva into the surrounding tissue
toddlers, young adults, and the elderly (falling trauma)
swellings of the lower lip (blue translucent hue)
Pseu­docysts
cyst-like spaces (filled with mucin and mɸ) lined by inflammatory granulation tissue or by fibrous connective tissue
Mumps
most common viral sialadenitis
Affects major salivary glands, particularly the parotids
Ranula
epithelial-lined cysts when the duct of the sublingual gland is damaged
“Plunging ranula” - a ranula so big it goes through the tissue connecting the two bellies of the mylohyoid muscle
Nonspecific bacterial sialadenitis
S. aureus and Streptococcus viridans
submandibular glands
Unilateral involvement of a single gland
usually secondary to ductal obstruction produced by stones (sialolithiasis)

5. Salivary Gland Neoplasms
Parotid Gland
Most of the tumors
Likely benign
Often appear in the fifth to seventh decades of life
Sublingual Gland
Fewest tumors
Likely malignant
Often appear somewhat later

6. Pleomorphic Adenoma Most common benign tumor in the parotid gland
Painless, slow-growing, mobile, discrete round masses
PLAG1 is overexpressed
Gray-white myxoid AND blue translucent areas of chondroid tissue
Called mixed tumors
show both epithelial and mesenchymal differentiation
ductal (epithelial) AND myoepithelial (mesenchymal) cells
Heterogeneity of the tumor = dominant histologic feature
arranged in duct formations, acini, tubules, strands, or sheets
typically dispersed within a mesenchyme-like background
Carcinoma ex pleomorphic adenoma
A carcinoma arising IN a pleomorphic adenoma
most aggressive of all salivary gland malignant neoplasms

7. Warthin Tumor (Papillary Cystadenoma Lymphomatosum)
Second most common salivary gland tumor
Round-oval encapsulated masses (2 to 5 cm in diameter)
Parotid gland only - Benign
50-70 year old smoking males
When cut open: pale gray surface with narrow spaces filled with serous secretions
spaces are lined by a double layer of neoplastic epithelial cells resting on a dense lymphoid stroma

8. Mucoepidermoid Carcinoma
most common primary malignant tumor of the salivary glands
mixtures of squamous and mucus cells
t(11;19) (q21;p13) translocation that creates a gene with MECT1 and MAML2 parts
When cut open: pale gray surface with mucin-filled spaces
Low-grade rarely metastasize (may invade)
5-year survival rate = 90%
High-grade metastasize (invasive)
5-year survival = 50%

9. Adenoid Cystic Carcinoma
Small cells with dark, compact nuclei and little cytoplasm
Minor salivary glands
Palatine gland
Most are here (50%)
Major salivary glands
Parotid and Submandibular glands
Tendency to invade perineural spaces
Very recurrent
Eventually, 50% or more metastasize to other sites (bone, liver, and brain)

10. Salivary Gland Pathology