Salivary Gland FNA: New Markers and New Opportunities for Improved Diagnosis

W.C. Faquin, M.D., Ph.D. Director, Head and Neck Pathology Massachusetts General Hospital Massachusetts Eye and Ear Infirmary Harvard Medical School Boston, MA Welcome to Boston….First day of Spring! The view from my window at home …. In Boston, SNOW is a 4-letter word! Disclosure of Relevant Financial Relationships

The USCAP requires that anyone in a position to influence or control the content of all CME activities disclose any relevant relationship(s) which they or their spouse/partner have, or have had within the past 12 months with a commercial interest(s) [or the products or services of a commercial interest] that relate to the content of this educational activity and create a conflict of interest. Complete disclosure information is maintained in the USCAP office and has been reviewed by the CME Advisory Committee.

Dr. Faquin declares he has no conflict(s) of interest to disclose. Salivary gland tumors are one of the most heterogeneous groups of neoplasms – So what role is there for FNA? SALIVARY GLAND FNA

Rationale for FNA: –Guide the clinical management/pre-op strategy: » Non-neoplastic Clinical follow-up » Benign tumor/low-grade carcinoma Limited resection » Metastatic disease to parotid LNs LN resection » Lymphoma Heme-Onc referral » High-grade primary carcinoma Radical resection CAUTION!

While most salivary gland tumors can be readily diagnosed in resection specimens, caution is warranted when interpreting small biopsies and FNAs! SALIVARY GLAND FNA: How Far Can We Go Using Cytomorphology Alone?

Usually Specific Diagnosis Sometimes Specific Diagnosis Usually Descriptive Diagnosis

Pleomorphic adenoma Adenoid cystic carcinoma Basal cell adenoma, tubulotrabecular and solid types

Warthin tumor LG mucoepidermoid carcinoma HG mucoepidermoid carcinoma

Basal cell adenoma, Acinic cell carcinoma Polymorphous low grade adenocarcinoma Membranous type

Acute and chronic sialadenitis Carcinoma ex PA Salivary duct carcinoma

Reactive lymph node Small cell carcinoma Basal cell adenocarcinoma

Lymphoma Mucocele Epithelial-myoepithelial carcinoma

Metastatic carcinoma to LN Oncocytoma

LESA SALIVARY GLAND FNA

Effectiveness of Cytomorphology alone: » Sensitivity: 86-100% Part of the reason for the high accuracy: A majority» Accuracy: of SG neoplasms are pleomorphic adenomas, » Benign/lowWarthin tumor, grade or metastatic vs HG malignant: cancer 81-98% » Specific lesion: 48-94% Salivary Gland FNA

With an expanded array of IHC and new molecular advances, FNA and small biopsies are becoming more effective. Increasing Availability of Molecular Markers For Salivary Gland Tumors

 Mammary analogue secretory carcinoma:

 ETV6-NKRT; t(12:15)

 Pleomorphic adenoma & Ca ex PA:

 PLAG1; t(3;8)

 HMGA2 rearrangement

 Clear cell carcinoma:

 EWSR1-ATF1; t(12:22)

 Mucoepidermoid carcinoma:

 MECT1/MAML2; t(11:19)

 Cribriform Cystadenocarcinoma:

 PRKD rearrangement

 Adenoid cystic carcinoma:

 MYB-NFIB; t(6:9) Ancillary Studies to Improve the FNA Diagnosis of Salivary Gland Tumors

 Immunocytochemistry

 LBP

 Smears

 Cell block

 FISH

 RT-PCR

 Next Generation Sequencing NORMAL SALIVARY GLAND Immunohistochemical Markers

SOX10

Ker 7, CAM 5.2 Ker 7, 19, CAM 5.2, EMA

Ker 5/6, S-100, p63, calponin, SM actin Ker 5/6, p63 Molecular Analysis at MGH NGS‐SNaPshot Panel

• Anchored Multiplex PCR (AMP)

• ~190 target amplicons across 39 genes

• High‐quality sequence: ‐ Staggered start sites ‐ >100X target coverage ‐ Molecular indexing ‐ Bi‐template coverage ‐ ~2% analytical sensitivity

• Fast turn‐around (~2 weeks)

• Cost‐effective (<$500)

• Small tissue amounts (5‐10 ng) Molecular Analysis at MGH NGS‐Translocation Panel

Master fusion panel (research)

ADCK4 FGR PDGFB AKT3 INSR PDGFRA ALK INSRR PIK3CA AR JAK1 PKN1 ARHGAP26 JAK2 PLAG1 ARHGAP6 MAML2 PPARG AXL MAST1 PRKACA BRAF MAST2 PRKCA BRD4 MET PRKCB CCDC6 MUSK RAF1 CD74 NFIB RET CHTOP NOTCH1 RHOA EGFR NOTCH2 ROS1 ERBB2 NRG1 TMPRSS2 ERBB4 NTRK1 EWSR1 NTRK2 FGFR1 NTRK3 quality controls: B2M FGFR2 NUMBL CTBP1 FGFR3 NUTM1 GAPDH IHC and Molecular Analysis Applied to Selected Salivary Gland Tumors Pleomorphic Adenoma Pleomorphic Adenoma (aka Benign Mixed Tumor)

• Most common salivary gland tumor in both children and adults

• 75-80% of parotid tumors & 50% of all salivary tumors

• 5-10% risk of malignant transformation

• FNA is highly accurate (>90%)

• DDX includes other matrix-producing tumors Most Pleomorphic Adenomas Are Accurately Diagnosed by FNA METACHROMATIC MATRIX ON DIFF-QUIK Pleomorphic Adenoma Immunohistochemistry:

• Markers of both ductal and myoepithelial cells:

• Positive for keratin 7, CEA, EMA, SOX10

– Positive for myoepithelial markers:

• Smooth muscle actin

• Calponin

• S-100

• Keratin 5/6

• P63

• GFAP Pleomorphic Adenoma

Cytogenetics: • PLAG1 rearrangements (50-60%) – Present in PAs in different tissues – Nuclear localization – Functions to activate transcription (Zn finger) • HMGA2 rearrangements (10%)

http://www.uniprot.org/uniprot/Q6DJT9 PLAG-1 Immunoreactivity: Overexpressed in 94% of PA

Does not distinguish benign from malignant

Contributed by Dr. J. Krane, BWH Carcinoma Ex Pleomorphic Adenoma: Most cases have PLAG1 or HMGA2 Rearrangements

Salivary duct carcinoma ex PA PLAG-1 Immunoreactivity and FISH in Ca Ex PA:

Bahrami et al, HN Pathology, 2012;6:328 Diagnostic Problems Arise from Variants of PA

• Cellular PA with sparse matrix

• Focal adenoid cystic–like areas

• Cytologic atypia

• Metaplasia

– Squamous

– Mucinous

– Sebaceous

– Oncocytic Pleomorphic Adenoma with Mucinous Metaplasia: Can be difficult to distinguish from MEC

Distinguished from MEC by: *Presence of myoepithelial cells *PLAG1 positive *p63 not useful Cellular Pleomorphic Adenoma: Can be difficult to distinguish from AdCC

Distinguished from AdCC by: *PLAG1 positive *CD117 & MYB +/- Adenoid Cystic Carcinoma Adenoid Cystic Carcinoma

• 4-10% of all salivary gland neoplasms

• 30-50 year-old women

• Indolent behavior but very poor long-term survival (<30-40% survival at 10 years)

• 3 histologic subtypes: Cribriform, tubular, solid

• FNA is most accurate for the cribriform type Adenoid Cystic Carcinoma: Classic Cribriform Pattern Adenoid Cystic Carcinoma Immunohistochemistry:

• Positive for keratin 7, CEA, EMA

• Positive for myoepithelial markers:

– Smooth muscle actin

– Calponin

– S-100

– Keratin 5/6

– P63

• SOX10+

• CD117 (KIT) +

• MYB + Adenoid Cystic Carcinoma

CD117 Immunohistochemistry:

• Over 90% are strongly positive for CD117 (KIT)

• Protein overexpression but no mutation identified

• Useful for all variants including solid forms

• Unusual IHC pattern Immunoreactivity for CD117 (KIT) in AdCC: Unusual Staining Pattern

Luminal Cells + Adenoid Cystic Carcinoma: Recent Advance – MYB Translocation Cytogenetics: • t(6:9) MYB oncogene-NFIB transcription factor • 64% MYB-NFIB fusion transcripts • Detectable by FISH or NGS The combination of CD117+ and MYB+ has high specificity for AdCC • MYB Immunohistochemistry: – 82-89% AdCC (+) – 14% non-AdCC tumors tested (+) – Nuclear stain Pusztaszeri et al, Cancer Cytopathol (2014) – Very effective in ETOH smears Persson et al PNAS (2009) and Mitani et al. Clin Cancer Res (2010) Salivary Gland Carcinoma With High Grade Transformation

• First described in 1988 for acinic cell carcinoma

• “Undifferentiated” appearance

• Very aggressive clinical course

• Can occur in different types of salivary gland carcinoma

• Often express elevated p53 and Ki-67 Adenoid Cystic Carcinoma With High Grade Transformation

Loses characteristic baseline IHC profile but will retain Molecular features of the primary tumor such as MYB rearrangement Mammary Analogue Secretory Carcinoma Mammary Analogue Secretory Carcinoma

 First described by Skalova et al in 2010

 Analogous to secretory carcinoma of breast

 Previously classified as acinic cell carcinoma or adenocarcinoma, NOS

 Absence of true serous-type acinar differentiation- lacks zymogen granules

 Most common in the parotid gland

 Low-grade biologic behavior FNA of Mammary Analogue Secretory Carcinoma Mammary Analogue Secretory Carcinoma:

Numerous small cytoplasmic vacuoles MASC Immunohistochemistry:

• Positive for:

– S-100

– Mammaglobin

– Keratin 7, 8, 19

– EMA

– GCDFP-15

– MUC1, MUC4

• Negative for:

– Myoepithelial markers (p63 etc)

– Androgen receptor

– DOG1 +/- MASC: Immunohistochemical Studies

GCDFP-15+ S-100+

Distinguished from MEC by S-100+, Mammoglobin+ Mammaglobin+, but p63 - Mammary Analogue Secretory Carcinoma: For difficult cases, test for rearrangement

 ETV6-NKRT Translocation:

 T(12:15)(p13;q25)

 MASC is only known salivary gland primary

 Detected on histology or cytology using:

 FISH

 RT-PCR

 Next-Gen Sequencing Acinic Cell Carcinoma Acinic Cell Carcinoma

 2-6% of all salivary gland neoplasms

 Low-grade malignancy

 F>M

 >90% parotid

 Serous acinar & intercalated duct differentiation

 PAS/D+ zymogen granules

 No specific molecular changes identified FNA of Acinic Cell Carcinoma Acinic cell carcinoma with low N:C ratio cells, basophilic cytoplasm, and cytoplasmic vacuoles Acinic Cell Carcinoma Immunohistochemistry:

• Positive for:

– Keratin 7

– CAM 5.2

– DOG1

– SOX10

– Keratin 7, 8, 19

– EMA

• Negative for:

– Myoepithelial markers (p63 etc) DOG1 and Acinic Cell Carcinoma

Discovered on GIST

Calcium-activated chloride channel protein

Strong diffuse staining seen in most acinic cell carcinomas SOX-10 and Acinic Cell Carcinoma SRY-related HMG-box 10 (SOX10) protein

Transcription factor: neural crest formation, and maintenance of Schwann cells and melanocytes.

Acinar cells and intercalated ducts

Diffuse strong nuclear staining seen in most acinic cell carcinomas SOX10 and Salivary Gland Tumors

POSITIVE

Acinic cell carcinoma

Adenoid cystic carcinoma

Epithelial-myoepithelial carcinoma

Myoepithelial carcinoma

Pleomorphic adenoma

NEGATIVE

Salivary duct carcinoma

Mucoepidermoid carcinoma

Oncocytoma

Warthin tumor Acinic Cell Carcinoma vs. Oncocytoma

ACC is distinguished by DOG1+, SOX10+, PAS-D+

Oncocytoma Acinic Cell Carcinoma MUCOEPIDERMOID CARCINOMA Mucoepidermoid Carcinoma

• “Mixed epidermoid and mucus-secreting tumor”

• Most common salivary gland malignancy in children and adults

• M=F

• Wide age range; mean age = 45 yrs

• Usually slow growing

• 90% and 40% 5-yr survival for LG vs HG Low Grade Mucoepidermoid Carcinoma: Hypocellular with few groups of bland epidermoid cells; Common cause of FN FNA Low-Grade Mucoepidermoid Carcinoma: Mucus-Containing Epithelial Cells LG MEC: Mucicarmine Stain Mucoepidermoid Carcinoma Immunohistochemistry:

• Positive for:

– Keratin 5,6,7,8,19

– EMA

– CEA

– p63

• Negative for:

– SM actin

– Calponin

– S-100

– SOX10 Mucoepidermoid Carcinoma and Ancillary Molecular Markers Cytogenetics: • t(11:19) translocation • MECT1/MAML2 • More common in low grade • Seethala et al, Am J Surg Pathol (2010) – 60% of MEC – LG 74%, IG 63%, HG 32% SUMMARY: Increasing Availability of Molecular Markers

 Mammary analogue secretory carcinoma:

 ETV6-NKRT; t(12:15)

 Pleomorphic adenoma & Ca ex PA:

 PLAG1; t(3;8)

 HMGA2 rearrangement

 Clear cell carcinoma:

 EWSR1-ATF1; t(12:22)

 Mucoepidermoid carcinoma:

 MECT1/MAML2; t(11:19)

 Cribriform Cystadenocarcinoma:

 PRKD rearrangement

 Adenoid cystic carcinoma:

 MYB-NFIB; t(6:9) SUMMARY

• Salivary gland cytology presents many diagnostic challenges • Evaluation based upon cytomorphology alone is limited • Selective use of IHC, FISH, and NGS for various proteins and genetic markers is helping to improve the effectiveness of salivary gland FNA Thank You!