04/13/2017

1

Salivary Gland Cytopathology –

Diagnostic Clues & Pitfalls

24th Annual Seminar In Pathology

Pittsburgh, April 2017

P.E. Wakely, Jr., M.D.

The Ohio State University

Wexner Medical Center

Columbus, Ohio

U.S.A.

Role of Salivary Gland (SG) FNA

• to distinguish

– a SG lesion from other H&N lesions/tissue

– benign/l-g neoplasms from high-grade ones

Role of Salivary Gland (SG) FNA

• to distinguish

– a SG lesion from other H/N lesions/tissue

– benign/l-g neoplasms from high-grade ones

• guide patient management

– identify lesions where surgery is not indicated

– identify lesions where surgery may be indicated,

but not necessary & patient followed clinically

04/13/2017

2

Role of Salivary Gland (SG) FNA

• to distinguish

– a SG lesion from other H/N lesions/tissue

– benign/l-g neoplasms from high-grade ones

• guide surgical management

– identify lesions where surgery is not indicated

– identify lesions where surgery may be indicated,

but not necessary & patient followed clinically

• potential complications

– bleeding/ infection/ facial nerve pain/ tumor seeding (rare)

• 709 cases (2 institutions), had both FNA + surgical excision

• benign v. malignant

– sensitivity: 67.4% (not counting ‘atypical’ as ‘malignant’)

– specificity: 98.9%

– NPV: 91.8%

– PPV: 94.1%

– accuracy: 92.2%

• no statistical difference between LBC & conventional smears

• no cell blocks

Cancer 2016;124:388.

Salivary Gland (SG) FNA

• SG tumors among the most heterogenous

encountered in FNA practice

• pitfalls:

– overlapping morphologic features

– cystic change

– metaplasia

• clear cell/ squamous/ oncocytic/ and mucinous

04/13/2017

3

Role of Salivary Gland (SG) FNA

• to distinguish

– a SG lesion from other H/N lesions/tissue

– benign/l-g neoplasms from high-grade ones

• guide patient management

– identify lesions where surgery is not indicated

– identify lesions where surgery may be indicated,

but not necessary & patient followed clinically

• render a specific Dx when possible

• complications

– bleeding/ infection/ facial nerve pain/ tumor seeding (rare)

mediocre - poor performance of

salivary gland FNA to provide

specific diagnoses is well

documented

▪ Colella G, Cannavale R, Flamminio F, et al. Fine-needle aspiration cytology of salivary gland lesions:

a systematic review. J Oral Maxillofac Surg. 2010;68:2146-2153.

▪ Hughes JH, Volk EE, Wilbur DC. Pitfalls in salivary gland fine-needle aspiration cytology: lessons

from the CAP Interlaboratory Comparison Program in Nongynecologic Cytology. Arch Pathol Lab

Med. 2005;129:26-31.

Risk stratification scheme

category overall

ROM

entities

non-diagnostic cyst contents

benign 2% non-neoplastic, PA, Warthin tumor

NUMP

18%

▪ monomorphic cellular basaloid neoplasm (MCBN)

- with fibrillar stroma

- with hyaline stroma

▪ monomorphic oncocytoid neoplasm (MON)

- with cyst contents bkgd.

- with other bkgd.

suspicious 79% ▪ MCBN with mixed/other stroma

▪ MON with mucinous bkgd.

▪ cellular basaloid neoplasm with coarsely

granular/vacuolated cytoplasm

malignant 100% ▪ pleomorphic basaloid neoplasm

▪ pleomorphic oncocytoid neoplasm

Griffith et al. 2015

04/13/2017

4

SG FNA – proposed Milan system category ROM management

non-diagnostic 10-20% repeat FNA vs. clinical F-U

non-neoplastic TBD clinical F-U/radiologic correlation

AUS TBD TBD

neoplasm

▪ benign

▪ uncertain malignant

potential

5-7%

20-40%

conservative surgery vs. clinical F-U

suspicious 70-80% surgery

malignant

▪ low-grade

▪ high-grade

85-95% surgery

Functional classification - primary lesions

• non-neoplastic conditions

• stromal dominant lesions

• oncocytic dominant lesions

• non-oncocytic cyto-B lesions

• cyto-M dominant lesions

• spindle cell dominant lesions

• basaloid dominant lesions

Functional classification - primary lesions

• non-neoplastic conditions

• stromal dominant lesions

• oncocytic dominant lesions

• non-oncocytic cyto-B lesions

• cyto-M dominant lesions

• spindle cell dominant lesions

• basaloid dominant lesions

U : PA, AdCCA. S: l-g MEC

U : WT. S: oncocytoma

U : inflammatory

S: acinic cell, MASC

Specific Dx:

U = usually; S = sometimes;

D = descriptive

D: BCA/adenoCA, AdCCA solid,

Epi/Myoepi CA, PLGA, clear cell

CA

D: myoepithelioma/CA, NF

S: adenoCA, SDC, h-g MEC

04/13/2017

5

Normal SG

normal parotid – cell block normal parotid – smear

rounded grape-like clusters

04/13/2017

6

normal acinar cells

benign duct cells

Non-Neoplastic Lesions

o sialadenitis

o acute/ chronic/ granulomatous

o cysts

o sialosis

04/13/2017

7

Acute Sialadenitis

acute sialadenitis

acute sialadenitis with crystalloids

04/13/2017

8

SG Non-Tyrosine (amylase) Crystalloids

• 31 cases

• 30-86 yrs; F:M, 1.2:1 93% = parotid

• FNA smears:

– background neutrophils, proteinaceous debris

• histology in 36%:

– cyst, sialolithiasis and sialadenitis, WT, cystadenoma,

cellular PA

• crystalloids were not seen with any malignant lesion

Lopez-Rios F, et al. Diagn Cytopathol 2001; 25:59

Chronic Sialadenitis

Chronic Fibrosing Sialadenitis – Küttner T.

• benign inflammatory process clinically simulating a neoplasm

• almost exclusive to the submandibular gland

• middle aged patients

• smears: low cellularity, scattered ducts with few acini, lymphoplasmacytic cells

Cheuk W et al. Am J Clin Pathol 2002; 117:103.

04/13/2017

9

Küttner ‘tumor’

parotid: granulomatous sialadenitis

04/13/2017

10

granulomatous sialadenitis

Functional classification - primary lesions

• non-neoplastic conditions

• stromal dominant lesions

• oncocytic dominant lesions

• non-oncocytic cyto-B lesions

• cyto-M dominant lesions

• spindle cell dominant lesions

• basaloid dominant lesions

04/13/2017

11

Stromal/Matrix Dominant

Lesions

PA

Adenoid Cystic CA

Polymorphous AdenoCA [PoA]

L-G MEC

Pleomorphic Adenoma • most common SGT

• >70% of all parotid tumors

• cytomorphology

– variable cellularity

– fibrillar chondromyxoid stroma

– cells merge with stroma

– variable cell shape: polygonal, plasmacytoid, spindle, stellate

– nuclei: round, slight anisonucleosis

– cytoplasm

• moderate, fine granular

• t(3;8) [upregulation of PLAG1] in 50-

60% of cases

04/13/2017

12

enormous amount of matrix

fibrillar edges

Myoepithelial Cells – ‘plasticity’

• Spindle

• Plasmacytoid

• Stellate

• Columnar

• Polygonal

• Clear Cell

• Basaloid

04/13/2017

13

spindle/stellate

PA: spindle cells

stellate

04/13/2017

14

stellate & spindled

plasmacytoid/hyaline

“cells have a generally eccentric nucleus, & a homogeneous,

ground glass or hyaline eosinophilic cytoplasm”

04/13/2017

15

plasmacytoid/hyaline

plasmacytoid/hyaline

PA- confusing cytologic variations

• minimal-to-no stroma [cellular PA vs. myoepithelioma]

• nuclear atypia [nucleomegaly]

• non-fibrillar stroma

• metaplastic changes [mucinous, clear cell,

squamous]

• necrosis

04/13/2017

16

PA: nuclear atypia

72 y/o ♂; PA, non-fibrillar stroma

non-fibrillar stroma; PA or AdCCA??

04/13/2017

17

PA ???

both PAs ???

PA Adenoid Cystic CA

04/13/2017

18

both PAs ???

Pleomorphic Adenoma Adenoid Cystic CA

cellular PA. 47 y/o ♀. pre-auricular – Dx was AdCCA

cribriform

04/13/2017

19

Pleomorphic Adenoma forms of metaplasia

• squamous

• sebaceous

• oncocytic

• mucinous bkgd.

• clear cell

mucinous PA

• epithelial stromal

interdigitation and

transition from

epithelial to spindle cells

mucinous PA

04/13/2017

20

mucinous PA, CB

infarcted PA – squamous CA?

PA - infarcted

04/13/2017

21

Case

• 16 year old girl

• painless 2.2 cm. R parotid mass, unknown

duration

• otherwise well; no relevant medical history

• FNA biopsy performed

16 y/o ♀, parotid

48 y/o ♂, PA – sq met

04/13/2017

22

PA – squamous metaplasia

PA – take home messages

• most cases have fibrillar stroma/matrix

• BUT, don’t just look at the matrix

– it may have a smooth sharp contour/ globules

– always look at the cells

• plasmacytoid – typically with more cytoplasm than seen

in AdCCA

• spindle

• infarction & metaplasia happen

04/13/2017

23

Cytologic Features ≠ Dx of PA

• cells in tubular/acinar formation, or

finger-like branching

• absence of chondromyxoid stroma

• mucus-secreting cells

– especially if readily identifiable/numerous

• large numbers of bare nuclei

• marked pleomorphism

Adenoid Cystic CA • 4-10% SGT

• 4th – 6th decade

• cytomorphology

- basaloid cells with rounded oval

nuclei without visible nucleoli

- matrix: generally spherical or

elongated with a glassy character

- matrix: sharp smooth border

surrounded by cells with little

merging of cells into stroma

• t(6;9) MYB overexpression, 60%

• CD117, MYB, SOX-10 +

Adenoid Cystic CA

04/13/2017

24

Adenoid Cystic CA

Adenoid Cystic CA

04/13/2017

25

Adenoid Cystic CA

AdCCA – somewhat tubular stroma

AdCCA – very tubular stroma

04/13/2017

26

AdCCA – pseudopapillary

AdCCA – misshapen stroma

SGT With Cribriform Pattern

• Adenoid Cystic Carcinoma

• Focally Present

– PA

– basal cell adenoma

– polymorphous adenoCA [PGA]

– epithelial / myoepithelial CA

– salivary duct carcinoma

04/13/2017

27

Polymorphous AdenoCA (aka PLGA)

• almost exclusive to minor SG

– 60% palate

• histopathology

– cytologic uniformity with

architectural diversity

• cytomorphology

– tubules, cords, linear groups

– bland isomorphic oval nuclei

– variable matrix

– clean background

Polymorphous AdenoCA (PoA)

• IHC positive

– p63, pan-CK, S-100,

vimentin

• IHC negative

– p40

• IHC usually negative

– calponin, SMA, GFAP

• IHC variable

– CD117

Head Neck Pathol 2015;9:79-84

43 y/o. met. to l.n. from palate

43 y/o ♀. R neck – metastatic PoA

04/13/2017

28

PoA. 38 y/o ♀, palate – morphologic diversity

PoA – cytologic uniformity/architectural diversity

Case

• 79-year old man

• 0.7 cm. R pre-auricular nodule x 2 weeks.

• history of lymphoma diagnosed >20 years ago

04/13/2017

29

04/13/2017

30

Diagnosis?

How would you classify?

Benign

- macrophages & mucin

Mucinous Lesion

Malignant Mucinous Neoplasm

Unsatisfactory:

- cyst contents: macrophages & mucin

Which one?

Benign

- macrophages & mucin

Mucinous Lesion

Malignant Mucinous Neoplasm

Unsatisfactory:

- cyst contents: macrophages & mucin

Which one?

04/13/2017

31

L-G MEC: abundant mucin

Low-Grade MucoEp CA

• most common mal. SGT • 30% of all major/minor SGT

• 40% outside major SG:

– palate, buccal mucosa, lip

– upper/lower resp. tract

• 80% low-grade

• wide age range

• CRTC1–MAML2 fusion

– t(11;19) (q14–21;p12–13), 1st

described in 2003

– 40-70% of MECs

04/13/2017

32

Low-Grade MucoEp CA

• CAP study Arch Pathol Lab Med.

2005;129:26-31.

– FN rate = 43%

• cytomorphology

– variable bkgd. mucin

– cell clusters/sheets

– monotonous rounded/oval

nuclei

– vacuolated cells

– ± oncocytic change

– keratinized cells

Low-Grade MucoEp CA

• CAP study Arch Pathol Lab Med.

2005;129:26-31.

– FN rate = 43%

• cytomorphology

– variable bkgd. mucin

– cell clusters/sheets

– monotonous rounded/oval

nuclei

– vacuolated cells

– ± oncocytic change

– keratinized cells

• D Dx when only

extracellular mucin

– mucus retention cyst

– mucinous metaplasia

• chronic sialadenitis

• sialolithiasis

• Warthin tumor

• pleomorphic adenoma

– metastatic mucinous

neoplasm

intermediate cells

04/13/2017

33

bland intermediate cells

L-G MucoEP CA

67 y/o ♀. L parotid

04/13/2017

34

67 y/o ♀. L parotid

L-G MEC: TALP

04/13/2017

35

January 1994

Oncocytic Dominant Lesions

WT

Oncocytoma

Oncocytic SG Neoplasms

Warthin Tumor

• A.S. Warthin 1929 – “adenolymphoma”,

– “papillary cystadenoma lymphomatosum”

• 2nd most common SGT

• parotid

• White > > Asian, Hispanic, African

• one of the few SGT with M > F

• association with cigarette smoking

04/13/2017

36

Warthin Tumor

WT: discrete nucleoli

Warthin Tumor

04/13/2017

37

WT: acutely inflamed

cell-block

04/13/2017

38

WT, cell-block

Sources of diagnostic error in the fine-needle aspiration

diagnosis of Warthin's tumor and clues to a correct

diagnosis.

• 16 cases, WT

• oncocytic epithelium: abundant = 81%

• necrosis/debris: abundant = 56%, scant = 19% [75%]

• squamous cells : abundant = 25%, scant = 38%

Ballo MS et al. Diagn Cytopathol. 1997;17:230-4.

04/13/2017

39

WT, crystalloids

WT, squamous metaplasia

WT, squamous metaplasia

04/13/2017

40

WT– squamous metaplasia

43 y/o ♂. parotid mass

43 y/o ♂. mucinous WT

04/13/2017

41

43 y/o ♂. mucinous WT. mucicarmine

WT: Cause of Error Cancer 2003;99:166.

• paucity or lack of characteristic WT

morphologic features

• overabundance of 1 or more of:

– atypia

– mucoid material /mucinous background

– spindle shaped cells

– cystic / necrotic / inflammatory debris

Oncocytoma

• many mistaken as WT

– 15 cases in our files

• 7 called Oncocytoma

• 4 called WT

• 3 called WT vs. Oncocytoma

• 1 salivary gl neoplasm

• cytomorphology

– sheets/cluster/single forms

– large polygonal cells

– voluminous cytoplasm • fine-coarsely granular

– smooth, rounded nuclei • small single nucleoli

– clean background

04/13/2017

42

Oncocytoma

54 y/o ♂. parotid mass

dx = oncocytic neoplasm

04/13/2017

43

subsequent surgery, 1 mos. later

OMEC. recurrence 1.5 yrs. later

Non-Oncocytic Cytologically

Bland Lesions

Acinic Cell CA

MASC

Epi/Myoepithelial CA

04/13/2017

44

Acinic Cell Carcinoma [AciCC]

• 2-6% SGTs

• age: peak 40-45 yrs.

• sites: parotid – 90%, lip,

palate

• histologic subtypes:

– solid, microcystic, papillary

cystic, follicular

• slow growing; metastases late

• SOX10, DOG-1 +

• no specific molecular marker

• cytomorphology

– monotonous acinar cells

– loose clusters

– lack acinar/’bunch of

grapes’ architecture

– single cells

– cytoplasm vacuolated,

basophilic granules

– ill-defined or sharp cell

borders

– ± oncocytic change

– ± lymphocytic infiltrate

– no matrix

acinic cell CA

04/13/2017

45

linear profile, sharp cell borders

Oncocytic SGTs

routinely & diffusely

oncocytic

• Warthin T

• Oncocytoma

focal/infrequently

oncocytic

• MucoEp CA

• Acinic CC

• Secretory CA [MASC]

• Salivary Duct CA

Oncocytic SGTs

Acinic CC

• SOX-10 +

• DOG-1+

• p63 negative

WT, oncocytoma,

MEC

• SOX-10 negative

• DOG-1 negative

• p63 + – diffuse in MEC

– focal in WT, oncocytoma

Schmitt AC et al. JASC 2014;3:303.

04/13/2017

46

Secretory CA (MASC)

• parotid/extra-parotid sites

• cytomorphology: resembles

AciCC lacking cytoplasmic granules

– cytoplasmic vacuoles

– monotonous rounded nuclei,

small distinct nucleoli

– proteinaceous bkgd.

– ± oncocytic change

• IHC

– S-100, GATA3, mamma +

• specific molecular alteration

– t(12;15)(p13;q25),

ETV6-NTRK3 fusion

lobular configuration

MASC: loose clusters, single cells

secretory proteinaceous bkgd.

vacuoles

04/13/2017

47

MASC

Epithelial-Myoepithelial CA

• <1% of all SGTs

• > 70% parotid; F:M = 2:1

• locally aggressive

• 2 cell types

– luminal epithelial

– abluminal myoepithelial

cells

• clear cell change

• IHC + for myoepithelial

markers

Epi/Myo CA - cytomorphology

• highly cellular

smears

• 3-dimensional

clusters

• single cells

• cellular monotony

• bare nuclei

• acellular basement

membrane-like material

– sometimes concentric

balls/spheres

04/13/2017

48

Epi-Myoepithelial CA

Epi-Myoepithelial CA: potentially mistaken as cellular PA

concentric spheres

Cytologically Malignant

(i.e. large/pleomorphic)

Neoplasms

Salivary Duct Ca

H-G MEC

Papillary Cystadenocarcinoma

CA ex PA

04/13/2017

49

Salivary Duct Carcinoma

• Kleinsasser et al., 1968

• tumors resembling ductal CA of breast

• 50-70 yrs. of age

• M > > F; 4:1

• sites: parotid (70%), submandibular, sublingual,

minor salivary glands

• aggressive neoplasm

– 50% distant mets

Salivary Duct CA

04/13/2017

50

SDC: apocrine

Salivary Duct Carcinoma - IHC

• Positive

– cytokeratin

– androgen receptor

– EMA

– CEA

– ERBB2 (HER-2/neu)

• Negative

– ER/PR

– myoepithelial markers

– Mucin

androgen receptor

High-Grade MEC

04/13/2017

51

H-G MucoEp CA

H-G MucoEp CA

(Papillary) Cystadenocarcinoma

• rare

• major SG: parotid (70%)

• papillary/cystic

• cells: mucinous, clear,

oncocytic

• slow growing

• cytopathology

– papillary clusters

– variable mucinous bkgd.

– monotonous smooth nuclei

04/13/2017

52

CystadenoCA

CystadenoCA

CystadenoCA

04/13/2017

53

Spindle Cell Lesions

Myoepithelial Neoplasia

Nodular Fasciitis

Schwannoma

Myoepithelial Neoplasia

• ~ ½ occur in parotid

• mimics cellular PA

• cytomorphology

– clusters/single cells

– primarily spindle; also stellate,

plasmacytoid

– isomorphic

– variable amount of cytoplasm

– clean background

– ± collagen

myoepithelioma: plasmacytoid

04/13/2017

54

40 y/o ♀. parotid tail

same case

myoepithelioma: spindle cell

04/13/2017

55

Basaloid Lesions

Basal Cell Adenoma

Basal Cell Adenocarcinoma

Adenoid Cystic CA

Functional classification - primary lesions

• non-neoplastic conditions

• stromal dominant lesions

• oncocytic dominant lesions

• non-oncocytic cyto-B lesions

• cyto-M dominant lesions

• spindle cell dominant lesions

• basaloid dominant lesions

U : PA, AdCCA. S: l-g MEC

U : WT. S: oncocytoma

U : inflammatory

S: acinic cell, MASC

Specific Dx:

U = usually; S = sometimes;

D = descriptive

D: BCA/adenoCA, AdCCA solid,

Epi/Myoepi CA, PLGA, clear cell

CA

D: myoepithelioma/CA, NF

S: adenoCA, SDC, h-g MEC

04/13/2017

56

1o Basal Cell Neoplasia

• 2-3% all SGT

• ♀:♂ = 2:1

• 75% parotid

• histologic patterns – solid, trabecular, tubular,

membranous

• cytopathology – irregular sheets basaloid

cells, variable stroma, ± palisading

• myoepithelial markers +

55 y/o ♀. parotid, basal cell adenoma

ddx: cellular PA, BCA, AdCystic CA

tubulotrabecular pattern

04/13/2017

57

narrow bands collagen stroma

narrow bands of collagen stroma

Functional classification - primary lesions

• non-neoplastic conditions

• stromal dominant lesions

• oncocytic dominant lesions

• non-oncocytic cyto-B lesions

• cyto-M dominant lesions

• spindle cell dominant lesions

• basaloid dominant lesions

04/13/2017

58

References

• Griffith CC, et al. SG tumors FNA cytology: a proposal for a risk

stratification classification. AJCP 2015; 143:839.

• Bishop JA, et al. Cytopathologic features of mammary analogue secretory

carcinoma. Cancer 2013; 121: 228-33.

• Hughes JH, et al. Pitfalls in salivary gland fine-needle aspiration cytology:

lessons from the CAP inter-laboratory comparison program in

nongynecologic cytology. Arch Pathol Lab Med 2005;129:26-31.

• Wakely PE Jr. Oncocytic and oncocyte-like lesions of the head and neck.

Ann Diagn Pathol. 2008;12: 222-30.

• Tyagi et al. Diagn Cytopathol 2015; 43:495.

• Chhieng DC, et al. FNA of spindle cell & mesenchymal lesions of the

salivary glands. Diagn Cytopathol 2000;23:253-59.