Malignant salivary gland
neoplasms
PathoBasic
27.05.2014
Localisation % malignant benign
Parotis 80% 20% 80%
Gl.
submandibularis10% 45% 55%
Gl. sublingualis 1% 90% 10%
Minor salivary
glands9% 45% 55%
Mucoepidermoid Carcinoma
Mucoepidermoid Carcinoma
• 16% of all salivary gland neoplasms
• 30% of malignant salivary gland neoplasms
• 53% occur in the major salivary gland:
– 45% parotis
– 7% submandibular
– 1% sublingual
Mucoepidermoid Carcinoma
• Occurence in the 1st decade is unusual but 9% occur
in the second decade
• Female predominance (62%)
• Association with other salivary gland tumors
• Association with radiation (7-32 yrs after!)
• Intraosseous variant (Mandibula)
Histology
• Mucous, intermediate and epidermoid cells, with columnar, clear cell and oncocytoid features
• Several systems have been proposed to grade this neoplasm, but none has been universally accepted
�but low-grade tumors rarely recure or metastasize; MIB-1 index >10% correlates with high histopathologic grade, increased recurrence, metastasis and decreased patient survival
• t(11;19)(q21;p13) : MECT1-gene (mucoepidermoidcarcinoma translocated gene1) and MAML2-Gens (mastermind like gene 2) in 60%. Might be associatedwith better prognosis
Mucicarmine
Mucoepidermoid Carcinoma
• Most patients have a favourable outcome
• In one study, 8% of patients died of disease: 11% and
5% for major and minor gland tumours, respectively
• Death resulted from unresectable locoregional
tumour, distant metastases or complications of
adjunctive therapy
Acinic cell adenocarcinoma
Acinic cell adenocarcinoma
• Serous acinar differentiation : zymogen type secretory
granules (diastase resistant, only weak reactive with
mucicarmine (DD muzinous cells))
• Second most common epithelial malignancy of salivary
glands (~ frequent like adenoca, NOS)
• 80% parotis
• together with pleomorphic adenoma and
mucoepidermoid carcinoma most common epithelial
salivary gland tumor in children
Histology
• Acinar cell
• Intercalated duct cell: cuboidal cells may be
prominent
• Vacuolated cells: contain zymogen granules but not
in the vacuole (PAS and mucicamine -)
• Clear cells (optical empty)
• Solide, microcystic, papillary-cystic and follicular
growth pattern
• IHC: Amylase + (CAVE: residual normal tissue +)
Prognosis
• ~35% recurrence rate
• ~16% rate of metastasis and disease
associated death incidence
Adenocarcinoma, NOS
• ductal differentiation but lacks any of the
histomorphologic features that characterize the
other defined types of salivary carcinoma
• second in frequency only to mucoepidermoid
carcinoma among malignant salivary gland tumours
• account for about 17% of carcinomas
Histology
• Semingly unlimited number of growth patterns
• Diagnosis of exclusion
• Grading into low-, intermidiate- and high grade
– Cytologic atypia and mitosis based
• Ductal or glandular differentiation is evident in all
cases
• Prognosis: dependent on stage and grade
Differential diagnosis
• Cellular pleomorphic adenoma/basal cell
adenoma: no penetration of the capsule and
replacement of adjacent tissue
• Polymorphous low-grade adenocarcinoma:
concentric whorl-like appearance,
mucohyaline background stroma; nearly all
PLGA occur in minor salivary glands
• Metastasis
Adenoid cystic carcinoma
Adenoid cystic carcinoma
• Modified myoepithelial (abluminal) and ductal
(luminal) differentiated cells (SMA highlights myoepithelial
cells)
• Cribriform, tubular and solid growth pattern (mixture
is frequent)
• Excessive basal lamina depositions
• 4th most frequent carcinoma of salivary glands (~10%)
Differential diagnosis
• Polymorphous low-grade adenocarcinoma:
– is extremely rare in major salivary glands
– only intraoral tumors are in the differential
– swirled appearance (eye of a storm like)
• Basel cell adenoma/ca. (vs. ACC solid pattern):
– no clear cytoplasm and angular, hyperchromaticnuclei
– palisaded appearance of the nuclei
Prognosis
• Indolent growth, but persistent and recurrentgrowth, late onset of metastasis
• Good 5yr survial but much poorer 10-20 yr survival(79% vs. 37%)
• Solid growth pattern has a worse prognosis (more than
30% solid pattern has the worst prognosis, any solid patternworsens the prognosis)
• Perineural invasion is associated with poorer survivaland higher recurrence rate
• Radiation is not sufficient alone for cure;Chemotherapy is only palliative