Salivary Gland Tumors Slide Seminar

Arghavan Etebarian DDS, MSc

February 2021

Case 1 –video 1 attached

A 15 yrs. old young lady

with a parotid mass

https://www.dropbox.com/s/l9tqx9ya6wgmmeq/1.mp4?dl=0

To see video #1, please find the attached video or, click

the below link to open it in the browser:

What is your diagnosis?

• A. Cystadenocarcinoma

• B. Metastatic squamous cell carcinoma

• C. Mucoepidermoid carcinoma

• D. Low grade salivary duct carcinoma

Mucoepidermoid carcinomaIntermediate grade

• 3 cell types

• No myoepithelial cells

• Solid and cystic spaces

• Sialomucin

PAS + Mucicarmine

Cystic low grade MEC

Intermediate cells and foci of epidermoid cells

Epidermoid cells with no keratinization

HMWCK +

Clear cells (PAS+, diastase sensitive)

High grade MEC Cellular anaplasia

MEC or Metastatic skin SCC ? CK7+ BER-EP4+

Two-level grading is more practical to use!

IHC panel for MEC• CK7 (Strong +)• CK14 (Scattered +)• P63 +( striated ductal phenotype, basal cells origin, Exclude Metastatic RCC)• MUC1, MUC4, MUC5AC +

• Myoepithelial markers-> Negative

• Mucicarmine staining

Prognosis for MEC

Correlate strongly with clinical stageTumor site

Adequacy of surgical procedure

Adjuvant therapy

• Importance of early diagnosis

Tumor size Tumor invasion Vascular/ perineural invasion Surgical margins

Case 2- video 2 attached

A 44 yrs. old woman with a submandibular

masshttps://www.dropbox.com/s/nkpxhabnkjeh2p5/2.mp4?dl=0

To see video #2, please find the attached video or, click

the below link to open it in the browser:

What is your diagnosis?

• A. Salivary duct carcinoma

• B. Adenoid cystic carcinoma

• C. Basal cell adenocarcinoma

• D. Polymorphous adenocarcinoma (PAC)

Sieve-like pattern

of small malignant basaloid cells

2 cell types: luminal and abluminal

3 growth patterns

Adenoid cystic carcinoma

1. Cribriform ( glandular)

-Numerous pseudocyst (punched out)-Some true cysts

2. Tubular ADCC

Inner epithelialOuter myoepithelial

3.Solid ADCC

Cellular atypia

Perineural and intraneuralinvasion

Centered around a vessel

Infiltrative borders

Pseudopapillarygrowth pattern

PAC?

-Ki67>10%

-GFAP+

Differential diagnosisfor ADCC

ADCC

A high grade malignancy and

histological grading is of less importance!

Clinical staging

Case 3- video 3 attached

A 55 yrs. old woman with a parotid mass

https://www.dropbox.com/s/73puz6564xbcrqw/3.mp4?dl=0

To see video #3, please find the attached video or, click

the below link to open it in the browser:

What is your diagnosis?

• A. Mucoepidermoid carcinoma

• B. Acinic cell carcinoma

• C. Secretory carcinoma

• D. Metastatic thyroid carcinoma

Acinic cell carcinoma

• 4 cell types

• 4 patterns: Solid, Microcystic, Papillary-cystic, Follicular

1. Acinar cells (PASD+)

2. Vacuolated cells (PAS -)( papillary cystic- microcystic variant)

3. Clear cells (PAS -) Rare!

4. Non-specific glandular cells

Prominent lymphocytic infiltrationGerminal center formation

1. Solid pattern

-Uniform basophilic acinar cells

-Necrosis !?-Mitotic figures: unusual

2. Microcystic patternMucinous, proteinaceous material

3. Papillary-cystic patternACC or metastatic PTC ?

4. Follicular patternMetastatic follicular thyroid carcinoma ?

• Well-differentiated ACC associated with lymphoid stromaMicrocystic growth pattern + dense lymphoid stroma

Low Ki-67 labelling index

Thin pseudocapsule

• High grade transformation (dedifferentiation) Conventional low-grade ACC + high grade ACC

High Ki-67 labelling

ACC diagnosis and treatmentDOG1 staining for ACC diagnosis (acinar differentiation) MUC3 positive in ACC ( not in MEC, ADCC)Always negative for P63 ( MEC is always +)

• Histological grade is stronger predictor of survival than TNM stage.• Surgical resection -> excellent results• Best survival rate of all salivary gland carcinomas

MASC 2010

SC 2017

PAS stain in ACC and MASC

S100 – in ACC S100 + in MASC

DOG1 + in ACC(apical and membranous)

Mammaglobin + in MASC

In SC ( no other salivary gland tumor!)

ETV6-RET ETV6-MET

Positive ETV6-NTRK3 gene fusion

100 % specific90.7% sensitive

Immunohistochemistry

Plays a limited, even though important rolein diagnosing salivary gland tumors

Assist the final diagnosis! CK7+/CK20-

Strongly recommended!

Thank you and have a lovely day