Update in the Management of Thyroid Neoplasms David R. Byrd, MD Department of Surgery University of Washington

Update in the Management of Thyroid Neoplasms

David R. Byrd, MD

Department of Surgery

University of Washington

NCCN - National Comprehensive Cancer Network

• yearly update from the NCI-designated comprehensive cancer centers (FHCRC --> FHCRC + UWMC)

• Consensus guidelines from the NCCN membership institutions

• not focussed on the practice of the community cancer practitioner

NCCN - Management of Thyroid Carcinoma -2001

Thyroid Nodule - History

Local Sxs

Risk factors

Function

Thyroid nodules

• 6-10% adult U.S. population– 5% are malignant

• FNA best initial test - 96% PPV

• U/S good to follow or document MNG

• thyroid scan good if symptoms of hyper- or hypothyroidism or if indeterminate cytology/multinodular goiter

• suppression most successful when TSH high

FNA Results of Thyroid Nodule

Benign --> F/U 6-12 months

cyst --> F/U 6-12 months

indeterminate --> repeat FNA, I123 scan if same results

follicular neoplasm --> I123 scan or surgery

suspicious --> surgery

carcinoma --> surgery

FNA

Results of I123 scan

“hot” --> check TFTs

“euthyroid” --> rarely CA, F/U only

“cold”* (still takes up some iodine, though less than normal gland)

*NOTE: 1. Nearly all cancers are “cold” 2. However, only about 10-15%

of “cold” nodules are cancer

I123 scan

Thyroid Carcinoma - Nodule Evaluation

©National Comprehensive Cancer Network

Thyroid Carcinoma - Nodule Evaluation


Pathology of Thyroid Cancer• differentiated thyroid cancer (DTC):

– papillary - commonly spreads to nodes (40-50%), excellent prognosis

– mixed - papillary and follicular - acts like papillary, excellent prognosis

– follicular - slightly worse than papillary, can spread to bone, less to nodes (15%); Hurthle cell Ca is variant

• medullary - sporadic vs. familial (MEN 2A), total thyroidectomy is treatment

• anaplastic - aggressive and fatal, surgical role is biopsy only

Thyroid Carcinoma - Papillary Carcinoma


Rationale for Total Thyroidectomy for DTC

• improved effectiveness for I131 ablation• lowers dose needed forI131 ablation• allows f/u w/ thyroglobulin levels• decreased recurrence• improved survival in high risk pts.

• decreased risk of pulmonary mets and dedifferentiated CA

Rationale Against Total Thyroidectomy for DTC

• increased RLN injury and hypoparathyroidism• contralateral disease not clinically relevant• survival nearly equivalent for low risk patients• I131 ablation not necessary for most patients• thyroglobulin levels not necessary for most

patients

Thyroidectomy for DTC - Technique

• know the anatomy

• protect RLN

• preserve all parathyroids

• know when to reassess or quit



Lymphadenectomy for Papillary or Mixed Thyroid CA

RLN

parathyroid









Thyroid Carcinoma - Follicular Carcinoma










? Residual Thyroid Cancer• 25 y/o woman with papillary thyroid cancer

– Capsular penetration– Lymph nodes not sampled

• Dx and Post-Rx (200 mCi) I-131 scans show thyroid remnant only– TG off TSH = 110 ng/dL

• Dx I-131 scan 1 year later negative– TG off TSH is still 100 ng/dL

Thyroid CancerPost therapy (10/98)

2055870

Tc-99m markers

I-131window

Thyroid CancerDiagnostic Scan (7/99)

2055870

Tc-99m markers

I-131window

? Residual Thyroid Cancer:FDG PET Scan 8/99

2055870

L Cervical Lymph Nodes

? Central Lymph Nodes

Case 1

• 60F undergoes L thyroid lobectomy for a solitary nodule w/ follicular cells on FNAC.

• Final path shows 2cm follicular adenoma and incidental 5mm papillary thyroid CA

• ?further management

Case 1 - issues

• ? Completion thyroidectomy --> NO

• ? Radioactive iodine therapy --> NO

• ? Thyroid suppression --> +/-

• ? F/u -6 month intervals with H & P

Result: the 2 cm nodule is benign and the 0.5cm nodule is an incidental carcinoma of minimal significance

Case 2

• 40M w/ solitary 1.5cm L thyroid nodule on exam

• h/o neck irradiation for enlarged thymus as child

• ?further management

Case 2 - Issues

This is a setting of higher risk of cancer - male, solitary lesion, and equivocal hx of neck irradiation:

minimal operation is thyroid lobectomy + isthmusectomy, proceed to total or subtotal thyroidectomy if bilateral nodules and/or if carcinoma found

frozen section is notoriously unable to definitively call carcinoma - therefore permanent pathology usually necessary to confirm carcinoma

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Update in the Management of Thyroid Neoplasms David R. Byrd, MD Department of Surgery University of Washington