Malignant Thyroid Disease

HISTORY OF PRESENT ILLNESS

10 years PTC slowly growing nodular ant. neck mass

2 years PTC rapid increase in the size of mass

6 months PTC hoarseness & difficulty of swallowing

Admission

Review of Systems

• No fever, no weight loss, no tremors

• No chest pain, no easy fatigability

• No abdominal pain

• Past Medical History: unremarkable

• Family History: unremarkable

Physical Exam• PR = 100/min• RR = 20/min• T = 37oC• No exopthalmos• 25x20cm multinodular, firm right

anterolateral neck mass• Palpable cervical adenopathies post. to

the sternocleidomastoid

SALIENT FEATURES

• 39 y/o, female

• Anterior neck mass

• Hoarseness

• Difficulty of swallowing

Malignant Thyroid Disease

1. What is your clinical impression? What are the differential diagnosis?

• Thyroid Cancer

Thyroid nodules

• Hx: time of onset, change in size, and associated symptoms such as pain, dysphagia, dyspnea, or choking

• Pain-raise suspicion of intrathyroidal hemorrhage in a benign nodule, thyroiditis, or malignancy

• Hoarseness- secondary to malignant involvement of the recurrent laryngeal nerve

• Increase risk of malignancy: Hx of ionizing radiation and family hx of thyroid cancer

PE:

• Thyroid masses- move with swallowing

• Hard, gritty, fixed nodules- more likely to be malignant

• Lymph node involvement- increases the risk of malignancy

39 y/0, female from Bicol PR=100/min RR=20/min T=37C

Growing nodular anterior neck mass (-) exophthalmos

Hoarseness and difficulty in swallowing

25x20 multinodular, frim, right anterolat neck mass which moves with deglutition, with a hard nodule (5x3) within the big mass

(-) Fever, weight loss, tremors Palpable cervical adenopathies

(-) chest pain, easy fatigability

(-)abdominal pain

Unremarkable PMH, FH

Specific Tumor Types:

Papillary Carcinoma• 80 % of all thyroid malignancies in iodine

deficient areas and in individuals exposed to external radiation.

• 2:1 female to male ratio• Mean age: 30-40• Euthyroid• Slow growing mass with calcification,

necrosis, or cystic change apparent grossly• Dysphagia, dyspnea, and dysphonia• Lymph node metastases

Specific Tumor Types:

Follicular Carcinoma

• More common in iodine deficient areas

• 3:1 female to male ratio

• Mean age: 50 years

• Solitary thyroid nodule

• Cervical lymphadenopathy is uncommon

• Distant metastasis may be present

Hurthle Cell Carcinoma

• Similar to follicular carcinoma

• Multifocal

• Bilateral

• More likely to metastasize to local nodes and distant sites

Medullary Carcinoma

• Neck mass with palpable cervical lymphadenopathy

• Dysphagia, dyspnea, dysphonia

• 1.5:1 female to male ratio

• Mean age: 50-60, patients with familial disease present at a younger age

• Unilateral, multicentric

Anaplastic Carcinoma

• Most aggressive

• Presents in the 7th or 8th decade of life

• Long standing neck mass which rapidly enlarges, may be painful

• Associated with dysphonia, dysphagia, and dyspnea

• Palpable lymphnodes

1. What is your clinical impression? What are the differential diagnosis?

Goiter-may result from iodine deficiency and/or TSH stimulation secondary to inadequate thyroid hormone synthesis

- may be diffuse, uninodular, or multinodular

-compression due to very large goiters may produce dyspnea and dysphagia

Differential Diagnosis:

• Benign Thyroid Nodule

• Thyroiditis

• Lymphadenopathy

• Metastasis from head and neck cancer

3. What work ups are needed, if any?• Laboratory Studies

• Thyroid function– Perform a complete assessment of

thyroid function in any patient with thyroid lumps.

– Higher-than-normal levels of thyroxine , triiodothyronine and thyroid-stimulating hormone (TSH) may indicate thyroid cancer.

• TSH suppression test– Cancer is autonomous and does not

require TSH for growth, whereas benign lesions do require TSH.

– Preoperatively, the test is useful for patients with nontoxic solitary benign nodules and for women with repeated nondiagnostic test results.

– Postoperatively, the test is useful for monitoring papillary thyroid cancer cases.

Imaging Studies

• Chest radiography, CT scanning, and MRI– Not usually used in the initial workup of

a thyroid nodule, except in patients with clear metastatic disease at presentation.

Echography

– Performed first in any patient with possible thyroid malignancy.

– Noninvasive and inexpensive, and represents the most sensitive procedure for identifying thyroid lesions and for determining the diameters of a nodule.

– Useful for localizing lesions when a nodule is difficult to palpate or is deeply seated.

– It may be used to help direct a fine-needle aspiration biopsy (FNAB).

FNAB

• FNAB is considered the best first-line diagnostic procedure for a thyroid nodule;

• FNAB is a safe and minimally invasive procedure.– Sensitivity of the procedure is near 80%,

the specificity is near 100%, and errors can be diminished using ultrasonographic guidance.

– False-negative and false-positive results occur less than 6% of the time.

Histologic Findings• Papillary thyroid carcinoma usually appears as a

grossly firm mass that is irregular and not encapsulated.

• Microscopically, it is multifocal, and a net invasion of the lymphatics may be demonstrated. Complete or partial papillary architecture with some follicles is present.

• The thyrocytes are large and show an abnormal nucleus and cytoplasm with several mitoses.

• Thyrocytes may have "orphan Annie eyes," that is, large round cells with a dense nucleus and clear cytoplasm.

• Another typical feature of this cancer is the presence of the psammoma bodies, probably the remnants of dead papillae.

Staging• The staging of well-differentiated thyroid cancers is related to

age for the first and second stages, but it is not related to age for the third and fourth stages. In the staging protocol, T is tumor, N is node, and M is metastasis.

• Younger than 45 years– Stage I - Any T, any N, M0 (cancer in thyroid only)– Stage II - Any T, any N, M1 (cancer spread to distant organs)

• Older than 45 years– Stage I - T1, N0, M0 (cancer only in thyroid, may be found in

one or both lobes)– Stage II - T2, N0, M0 and T3, N0, M0 (cancer only in thyroid

and >1.5 cm)– Stage III - T4, N0, M0 and any T, N1, M0 (cancer spread

outside thyroid but not outside of neck)– Stage IV - Any T, any N, M1 (cancer spread to other parts of

body)

3. What are the treatment options?

A.TOTAL THYROIDECTOMY

B.SUBTOTAL THYROIDECTOMY

C.NECK DISSECTION

TOTAL THYROIDECTOMY

- 30%-87.5% of PTC involve the opposite lobe

- 7%-10% recurrence rate in the contralateral lobe

- Lower recurrence rate

- For earlier detection and treatment of metastatic CA with radioactive iodine therapy

Indications of Total Thyroidectomy:a.) Patients > 40 y/o with papillary or

follicular CA

b.) Patients with thyroid nodule and history of radiation

c.) Patients with bilateral disease

SUBTOTAL THYROIDECTOMY- Lower incidence of complications

A. Hypoparathyroidism

B. Recurrent laryngeal nerve injury

C. Superior laryngeal nerve injury

NECK DISSECTION

- For managing lymphadenopathies

- For clinically palpable cervical nodes (as in the case) verified by MRI or CT scan

Management of Patient with Papillary Thyroid CA

Management - Surgery

1. Total Thyroidectomy (TTx)– PTA may be multifocal/bilobal– ↓ incidence of local recurrence– ↓ risk of anaplasia in any residual tissue– ↓ incidence of distant recurrence (by

facilitating diagnosis of distant metastasis by RAI scan)

– ↑ sensitivity of blood thyroglobulin (Tg) levels to predict recurrence/persistence

Management - Surgery

2. Modified Radical Neck Dissection– Removal of cervical lymph nodes– Spares sternocleidomastoid muscle,

internal jugular vein and spinal accessory nerve

– All tissue in the anterior triangle of the neck from the hyoid bone to the clavicle is removed

– Dissection along the spinal accessory nerve is most important because this is a frequent site of metastatic disease

Immediately Post-Op

• Wound care and analgesia

• Analgesia

• Monitor serum thyroglobulin

• Check for any possible complications

• Prep patient for RAI scan and treatment

4-6 Weeks Post-Op

• Serum thyroglobulin determination• Radioactive Iodine Scanning and treatment

(RRA)– Discontinue L-thyroxine 8 weeks prior to scan

• First 6 weeks of this: give synthetic T3

• Remaining 2 weeks prior to scan: discontinue T3 and recommend low iodine diet

– Place patient of L-thyroxine again after procedure– RAI scan looks for persistent/recurrent disease– RAI treatment may destroy microscopic cancer cells– ↑ sensitivity of serum Tg improved during follow-up

4-6 Weeks Post-Op

• TSH Suppression– Via L-thyroxine (which also serves as

replacement therapy for TTx)– ↓ recurrence by ↓ growth stimulus to

any possible residual thyroid cancer cells

– circulating TSH levels • 0.1 mU/L in low-risk patients• < 0.1 mU/mL in high-risk patients

Post-Op

• Thyroglobulin Measurement– If patient taking L-thyroxine: < 2 ng/mL– Otherwise: <3 ng/mL

• If > 3 ng/mL; highly suggestive of metastasis /persistent normal thyroid tissue, especially if TSH also rises (eg. discontinuation of L-thyroxine as prep for AI scan)

Long Term

• PE every 3-6 mo for 2 yrs then annually

• Serum Tg at 6 and 12 mo then annually

• 131I whole body scan (WBS) every year until 2 negative scans

• Periodic ultrasound and Chest X-ray

WBS - Conventional

WBS – recombinant thyrotropin• Safer, effective means of stimulating 131I

uptake and serum thyroglobulin (Tg)

• For patients:– Alternative to traditional LT4 withdrawal

– Inability to generate endogenous TSH

– Unable/unwilling to undergo LT4 withdrawal

– Enhance the sensitivity of Tg in thyroid CA follow-up

• Hypothyroidism is contraindicated

5. What are the possible complications of your

treatment?

Bleeding

• Intraoperative bleeding stains the tissues and obscures important structures.

•An unrecognized or rapidly expanding hematoma can cause airway compromise and asphyxiation.

• increases the risk of other anatomic complications

•Deliberate dissection and fastidious hemostasis are essential to prevent this complication.

Injury to the recurrent laryngeal nerve

•Mechanisms of injury to the RLN include complete or partial transection, traction, contusion, crush, burn, misplaced ligature, and compromised blood supply.

•The consequence of an RLN injury is true vocal-fold paresis or paralysis.

•Occurs in <1% of px undergoing thyroidectomy

Hypoparathyroidism

• Parathyroid glands produce parathyroid hormone (PTH), which is intimately involved in the regulation of serum calcium.

• Direct trauma to the parathyroid glands, devascularization of the glands, or removal of the glands during surgery can cause temporary or permanent shutdown, which results in hypocalcemia.

•Rate of permanent hypoparathyroidism - <2%.•Rate of transient hypoparathyroidism- 50%

Injury to the superior laryngeal nerve

Trauma to the nerve results in an inability to lengthen a vocal fold and, thus, an inability to create a high-pitched sound.

Rate of injury to the external branch of the SLN - 15%

Infection

Infection was the major cause of death from thyroid surgery during the 1800s.

Today, infection occurs in less than 1-2% of all cases.

Hypothyroidism

Hypothyroidism is an expected sequela of total thyroidectomy.

should never be left untreated long enough to elicit signs and symptoms of myxedema (eg, hair loss, large tongue, cardiomegaly).

Expect, diagnose, and promptly treat postoperative hypothyroidism.

Thank you!