LYMPH NODE FNAB & ANCILLARY TESTING

Drs. E. Filter, D. Morrison & M. Weir

INTRODUCTION

Lymphadenopathy in setting of thyroid nodule or post thyroidectomy

- requires imaging, work-up- sometimes diagnosis - FNAB

LN diagnosis & staging important - changes management

Ancillary testing - useful with FNAB

OBJECTIVES

For Lymph Node FNABs:1. State roles of ancillary testing for

- thyroglobulin, flow cytometry

2. List reasons for non-correlation between

FNAB & thyroglobulin

CASE 1

LPP 51 year old female

Hx pap thyroid ca 1995, surgery, RAI Serum Tg undetectable, Stim Tg <1,

WBS - N Suspicious left neck level 3 lymph

node FNAB & Tg testing on sample

Nuclear atypia

Comparison to benign thyroid epithelium

Pap society atlas

CASE 1

Jan 2014- FNAB: positive for papillary

carcinoma

- Tg on FNAB sample: abnormal

QUESTIONS: why do the Tg at all? why not do just Tg (omit

FNAB)

CASE 1

QUESTIONS: 1. Why do the Tg at all?

- literature to support reflex testing

- cost conscious, limited resources

2. Why not do just Tg alone (omit FNAB)?

- it is only for DTC (foll, pap ca)

- + FNAB has high PPV

LITERATURE

Thyroglobulin Wash Testing in the Surveillance of Patients with Thyroid Carcinoma: Proposal for a Reflex Test

Anastasiya Pigal, Rossitza Draganova- Tacheva, Charalambos C. Solomides, Marluce Bibbo.

Bibbo paper

Retrospective study Determine if Tg sample contributed

to management of cases with + FNAB

30 susp/pos LN or thyroid bed FNABs

Hx of or subsequent histologically proven differentiated thyroid ca (DTC – foll or pap ca)

Lit review (DTC only)

Bibbo paper

Susp/Pos FNAB

Tg > 1 ng/mL

Tg < 1 ng/mL

Tg negative DTC on F/U

30 Bibbo23 LN, 7 bed

22 (73%) 8 (27%) 7

577 Lit review

548 LN, 29 bed

557 (97%)

20 (3%) 14

All treated regardless of Tg outcomes

Bibbo paper

Their data & literature review:

- recommend reflex Tg testing of FNAB

ONLY for neg/indeterminate cytology

- + Tg in setting of susp/pos FNAB

- no change management

PRACTICE REFLECTION

Now:- in Plasmalyt: divide for cyto/Tg- all samples sent are tested

Should we change our practice?- medium to store Tg?- hold Tg until FNAB reported?- who initiates Tg testing?

CASE 2

VB R thyroid nodules

- lower 2.6 cm nodule, microcalcifications

- 2.2 cm R cervical LN > 4 cm Lung nodules FNABs x3 (2 nodules, LN)

Case 2 Thyroid NodulesThyroid Nodules:

● Location: Right Mid Lobe● Approximate Size: 1.6 x 2.2 x 2.4 cm● Location: Right Lower Lobe● Approximate Size: 1.7 x 2.6 cm x ?(went

below clavicle)

● Echogenicity: Both Hypoechoic● Taller than Wide (transverse) Ratio: Yes● Vascularity: Yes● Margins: Indistinct

Case 2 Lymph Node Biopsy

Lymph Node:● Location: Right Cervical Level 4.● Approximate Size: 2.8 x 3.4 x >4cm● Echogenicity: Hypoechoic● Appearance: Round with no fatty hilum● Vascularity: Yes● Margins: Regular

+ CALCITONIN

Pap society atlas

CASE 2

FNAB- medullary carcinoma (thyroid,

LN)

Tg on FNAB sample not elevated

Discrepancy between +FNAB & -Tg- not DTC, so Tg expected to be

neg Note: Tg alone would be false neg

CASE 2

Reasons for negative Tg when +FNAB?

CASE 2 Reasons for negative Tg when

+FNAB- not papillary or follicular

carcinoma- sampling (false neg)

- passes different material- low cellularity/unsatisfactory

- test issue (false neg)- collection tube type- circulating antithyr Ab

Roseneide et al Thyroid 2014Thyroglobulin in the Washout Fluid of Lymph Node Biopsy

Summary 1 (Cases 1&2)

Role of Tg testing:- not for susp/pos LN outcomes- use with FNAB, not alone

Reasons for non-correlation LN FNAB & Tg:

- not DTC- sampling, test issue

CASE 3

OH Left thyroid nodule Left level 4 lymph node FNABs x2

THYROID FNAB

Few groups, focal atypia

crowdingpseudoinclusionsgrooves

CASE 3

Thyroid FNAB- Indeterminate for pap ca (AUS)

LN FNAB- Indeterminate

- low cellularity, few epithelial groups Tg on FNAB elevated

CASE 3

Role of Tg

- best use: indeterminate/neg FNAB

- has high sensitivity in this setting

- will impact management

CASE 3

Reasons for positive Tg when neg/ind FNAB?

CASE 3 Reasons for positive Tg when

neg/ind FNAB- sampling

- go thru thyroid for central LN- cystic LN, low cellularity/unsat- thyroid bed residual thyroid

tissue

- test issues- saline collection – matrix effect- high serum Tg- thyroid palpation effect (Tg

released)

Roseneide 2014

CASE 4

HK

Hx papillary carcinoma 2006 Thyroid nodule in bed query LN FNAB

CASE 4

?LN FNAB- low cell, negative (lymphocytes)- may not be representative

Tg on FNAB not elevated

CASE 4

Is a neg Tg reassuring when FNAB neg?

- maybe- beware sampling:

- FNAB low cellularity or unsat

- Tg sample may not be representative

Tg TESTING ISSUES

Lack consensus, international standards

for performance & interpretation

Measure Tg FNAB same method as sTg

Tg free serum in Tg assay kit preferable to washing in saline

Use 1 mL fluid, plain serum tubes Cut off for measurement -

controversial

Roseneide 2014 Thyroid

PRACTICE REFLECTION

Now:- in Plasmalyt, not

serum tube- variable volumes

Should we change our practice?

- Tg free serum?- serum tubes- 1 mL

Summary 2 (Cases 3&4)

Role of Tg testing:- use for neg/indeterminate FNABs- will impact management- beware of neg Tg when unsat/lo

cell FNAB

Reasons for non-correlation LN FNAB - Tg:

- sampling, test issues

CASE #5:CERVICAL LYMPHADENOPATHY

Case #5 72 year old female Hx non-diagnostic thyroid nodules

No clinical risk factors, stable sizes, no suspicious sonographic features on left, benign biopsy (low cellularity) on right.

Now presenting with left cervical lymphadenopathy

FNA of lymph nodes (levels 4, 5b) obtained

Thyroid Nodules

Lymph Nodes

Smear (Pap stain)

Cibas, E. Cytology, 3rd, Ed. 2009

Air dried smear (DiffQuik stain)

Case #5

Flow cytometry reported 2 monoclonal B-cell populations

The morphologic findings and flow cytometry results are consistent with a B-cell lymphoproliferative disorder

A non-Hodgkin lymphoma (NHL) is favoured

Ancillary Studies in Lymphoma Dx

Immunocytochemistry panels Molecular studies Flow cytometry

Flow Cytometry

Flow Cytometer

Cibas, E. Cytology, 3rd, Ed. 2009

Flow Cytometry

Markedly improves the diagnostic sensitivity in cases of suspected NHLs

:. recommended ancillary study if clinical DDx includes lymphoma BUT: less useful in cases of Hodgkin

lymphoma and plasma cell dyscrasias

Flow Cytometry

Requires submission of your sample in flow medium (RPMI) Refrigerated Can use Plasmalyte if

RPMI not immediately available

Formalin and alcohol-based solutions (e.g. Cytolyt) not optimal for flow interpretation

www.lifetechnologies.com

Role of FNA in Lymphoma Dx

DISADVANTAGES

Samples may be non-diagnostic Necrosis Fibrosis Poor technique

Samples may not be representative Benign and malignant lymphoid cells can co-exist in same

lymph node Reactive lymphadenopathies and malignancies can

mimic lymphomas Grading of lymphomas poorly reproducible in

cytologyDeMay, R. The Art & Science of Cytopathology,

2nd Ed., 2012

Role of FNA in Lymphoma Dx

ADVANTAGES

Does not interfere with subsequent histologic interpretation

Can help select best node for excision Ideal in certain situations:

Deep or surgically inaccessible nodes Patients of high surgical risk Rapidly progressive and/or extensive disease

Can document transformation to a higher-grade lymphoma (e.g. Richter syndrome)

DeMay, R. The Art & Science of Cytopathology, 2nd Ed., 2012

In Summary…

The diagnosis of lymphoma requires a clinicopathologic approach AND use of ancillary studies

Although there are known pitfalls, FNA cytology can be very useful for proving or excluding a lymphoma

Flow cytometry is key to diagnosis

TAKE HOME MESSAGES

Role of ancillary testing for LN FNABs

- Tg: ind/neg FNABs - flow cytometry: confirm reactive/lymphoma

Reasons for non-correlation FNAB & Tg:

- sampling- nature of lesion- test issues