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