5/18/2013 Most thyroid nodules are benign Incidence Etiology Risk - - PowerPoint PPT Presentation

5/18/2013 1 Thyroid nodules: new techniques in evaluation

Postgraduate Course in General Surgery

Jessica E. Gosnell MD

May 18, 2013 2

Most thyroid nodules are benign

• Incidence
• Etiology
• Risk factors
• Diagnosis

– Gene classification system

• Treatment

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(Tuttle and Lehoeuf, Endo Metab N Am) (ATA revised guidelines for Thyroid Nodules , Thyroid 2009)

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Most thyroid nodules are benign

• thyroid nodules occur in 77%
• f the world’s population
• palpable thyroid nodules
• ccur in about 5% of women

and 1% of men in the US

• more common in women,

advancing age, iodine deficiency, family history and radiation exposure

• high resolution ultrasound can

detect nodules in 19-67%, with increasing rates in women and the elderly

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(Tuttle and Lehoeuf, Endo Metab N Am) (ATA revised guidelines for Thyroid Nodules , Thyroid 2009)

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Thyroid cancer is now the most rapidly increasing cancer in women

• Approximately 37,200 new

cases of thyroid cancer were diagnosed in 2009

• Yearly incidence 3.6 per

100,000 in 1973 --> 8.7 per 100,000 in 2002

• Most of the change is

attributed to increases in papillary thyroid cancer, which comprises 90% of all thyroid cancers

• Almost have of the rising

incidence consisted of tumors <1cm

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Thyroid nodules: differential diagnosis

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(Gosnell and Clark, Management of thyroid nodules, in Cameron’s Current Surgical Therapy, 10th ed, 2010)

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Thyroid nodules: History

• Symptoms of hypo,

hyperthryoidism

• Local symptoms in the

neck

– dysphagia, dyspnea, dysphonia – neck pain

• family history of thyroid or
• ther cancers
• exposure to ionizing

radiation to the head and neck

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Physical exam

• vitals
• eye signs

– stare, lid lag, exophthalmos

• visible, palpable nodules

– fixed mass, tenderness

• deviation of midline

structures

• cervical lymphadenopathy
• cardiac
• extremities

– pretibial myxedema –

• tremor
• skin

– rash, cutaneous lichen amyloidosis

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Pemberton’s sign

• bstruction of vena cava

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Most thyroid cancers are biochemically “silent”

• TSH is the signal best test to assess for thyroid

dysfunction

• T3, T4 as indicated
• thyroglobulin

– Suh et al., Serum thyroglobulin is a poor diagnostic biomarker of malignancy in follicular and Hurthle-cell neoplasms of the thyroid.

• 366 pts with follicular/Hurthle cell lesions
• Tg levels>500mug/L had positive predictive value of

0.75

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(Suh et al., Am J Surg 2010Jul;200:41)

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Thyroid nodules: imaging

• Ultrasound

– better than palpation and scintigraphy for thyroid nodules and cervical lymph nodes – inexpensive, non-invasive – provides valuable characteristics of the nodule (calcifications, vascularity, borders) – cannot distinguish between benign and malignant lesions

Thyroid nodules

Ultrasound for the Endocrine Surgeon, Surgery 2005, 138(6):1193

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Value of preoperative ultrasound

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Unsuspected disease was found by ultrasonography in 52 patients (34%) and altered the operative approach to include dissection

• f the central lymph nodes in 32 patients, ipsilateral nodes in 21

patients and contralateral nodes in 9 patients (Kouvaraki et al, Surgery 134:946, 2003)

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Thyroid nodules: ultrasound guided FNA

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(J Mechanick, Endocrine Surgery, 2004)

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Thyroid scintigraphy= Limited role!

• Historically, used to characterize thyroid

nodules by their ability to take up isotope, as a way to distinguishing benign from malignant

– up to 80% of thyroid nodules are “cold”, only 20% of these are malignant

• Now, useful in patients with biochemical

hyperthyroidism

– distinguish between Graves’ disease, toxic adenoma and Plummer’s disease (toxic MNG)

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toxic adenoma in the left superior pole toxic MNG

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Other imaging modalities

• Useful to evaluate for retrosternal extension,

tracheal deviation/compression

– CT scan

• avoid iodinated contrast in patients that may need RAI

treatment

– MRI

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FNA biopsy for thyroid nodules: when is it indicated??

• Most do not advocate biopsy of all thyroid

nodules

– >1cm, worrisome ultrasound findings, rapid enlargement, family history or radiation exposure

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(Gharib and Burguera, Thyroid incidentalomas. Prevalence, diagnosis, significance and

• management. Endocrin Metab Clin North Am 20002 Mar;29(1):187)

(Cooper et al. Revised ATA guidelines 2009)

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FNA biopsy for thyroid nodule

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10 – 50% risk

• f cancer

Need for more accurate diagnostic tests than FNA cytology! Benign (70%) Malignant (<10%)

Indeterminate/suspicious (5-50%) Nondiagnostic (<10%)

FNA biopsy

Total thyroidectomy (lobectomy) "Diagnostic" thyroidectomy 10 – 50% risk

• f cancer

> 90% accurate

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FNA: typical papillary thyroid cancer

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“Orphan Annie eyes”

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Indeterminate FNA cytology

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follicular cell lesion Hurthle cell lesion

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Gene Expression Classifier

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• Measures the expression of 142

genes on a microarray chip

• Expression levels then used to

classify nodules as benign or malignant

• Useful for:
• “follicular lesion of

undetermined significance” (FLUS)

• “atypia of undetermined

significance” (AUS)

• “suspicious for Hurthle/follicular

neoplasm”

• FNA done. Cytology done

first, if still non-diagnostic, goes for gene expression

• If insurance does not cover, out of

pocket cost $300 or less

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Gene Expression Classifier

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Indeterminate FNA* Surgical consult Gene expression classifier Ultrasound surveillance suspicious Benign >95% NPV

“follicular lesion of undetermined significance” (FLUS), “atypia of undetermined significance” (AUS), “suspicious for Hurthle/follicular neoplasm”

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Preoperative diagnosis of benign thyroid nodules with indeterminate cytology

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• New England Journal of Medicine

2012 August 23;367(8):705-15 Alexander EK et al

• 19 month, prospective multicenter validation study
• 4812 fine-needle aspirates
• 265 cytologically indeterminate aspirates
• Gene-expression classifier correctly identified 78 of the 85

nodules as suspicious

• Negative predictive values for “atypia (or follicular lesion of

undetermined significance”, “follicular neoplasm or suspicious for follicular neoplasm” or “suspicious findings” were 95%, 94% and 85%, respectively

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Indications for thyroidectomy in patients with thyroid nodules

• FNA/gene-classifier suspicious/ malignant

findings

• worrisome nodules despite benign FNA/gene-

classifier findings

– >4cm, growing

• local compression
• retrosternal extension
• family history of thyroid cancer and exposure to

ionizing radiation

• selected cases of hyperthyroidism (toxic MNG,

Graves’ disease)

• cosmesis

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The role of diagnostic surgery

• Indicated for follicular or Hurthle cell

neoplasms, possibly if suspicious on gene- classifier

• Indicated for patients with worrisome clinical

findings

– growing nodules, risk factors for thyroid cancer

• Should be considered for nodules > 4cm

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The role of intraoperative frozen section

• useful for nodules suspicious for papillary

thyroid cancer but not follicular or Hurthle cell nodules

• useful for cervical lymph nodes, parathyroid

glands

(Livolsi, Surgical Pathology of the Thyroid, 2nd ed, 2007)

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Gosnell and Clark. Management of Thyroid Nodules. In Cameron, Current Surgical Therapy, 10th ed, 2011

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Thank you