Cancer of thyroid gland

Dr. Zahoor AhmadPGR, SU-I

SZMC/H. RYK, Pakisatan

Lymph vessels:

drain to Prelaryngeal (Delphian), pretracheal paratracheal nodes.

Parasympathetic vagus

Sympathetic superior, middle, inferior sympathetic ganglia

Superior thyroid v (to IJV) middle thyroid v. (to IJV) Inferior thyroid v. (to

brachiocephalic trunk)

Sim’s triangle1. lateral common Carotid artery2. medially Trachea3. superiorly Inferior pole of

thyroid

Lobule: 20-30 follicles Follicle: functional unit Follicular cells Contains colloid Parafollicular cell or C-cell

1% of total 3/million cases Women 3 times more than men. Peak incidence 40s. Papillary 60%, follicular 20%,

anaplastic 10%, medullary 5%, malignant lymphoma 5%.

RADIATION (most important) Family history of Goiter (MEN-II. ret

oncogene) Personal history of Autoimmune

thyroiditis Inheritance of oncogenes (ret/PTC1,

ret/PTC3) Male sex Age > 45 years

Chief complaints Rapidly growing, Painless, palpable,

irregular, solitary nodule. Cervical lymph node enlargement Associated symptomsNeck pain, hoarseness, dysphagia,

dyspnea, stridor, hemoptysis

Thyroid gland Soft tissues of neck Solid, soft, mobile, or fixed? Tenderness? Laryngoscopy if hoarse preop!

Baseline labs Tumor markers (S. thyroglobulin,

S. calcitonin, CEA, ) CXR TSH, TFTs IDL

FNAC Trucut biopsy Incisional biopsy USG neck CT scan neck & thorax MRI Thyroid scan

Tumors of Follicular Cell OriginDifferentiated„ „ Papillary 60%„ „ Follicular 20%Undifferentiated „ „ Anaplastic 10%

Tumors of Parafollicular„ „ Medullary 5%„Other„ „ Lymphoma 5%

Primary

1. Follicular cells (papillary, follicular, and anaplastic)

2. Para-follicular cells (medullary)3. Lymphocytes (lymphoma)

Secondary1. Metastases2. Local infiltration

„TNM system

T1 2cm T2 2-4cm T3 >4cm, limited to thyroid T4a Any size, invasion of SQ,

trachea, esophagus, RLN, paravertebral fascia, carotid artery

N0 no nodes N1a Level VI N1b All other levels

M0 no metastases M1 distant mets

Stage I T1, N0, M0Stage II T2, N0, M0 T3, N0, M0Stage III T4, N0, M0

any T, N1, M0Stage IV any T, any N,M1

AMES system AGES System GAMES system MACIS system University of Chicago system

Age Metastasis Extent/ extrathyroid Size

Age Grade Extent Size

Metastasis Age Completeness of excision Invasion Size

staging system for papillary carcinoma Class I— disease limited to the thyroid glandClass II— lymph node involvementClass III— extrathyroidal invasionClass IV — distant metastases

Most common (60%) Women 3 times more common 30-40 years of age Radiation exposure as a child Multifocality Slow growing microscopically BRANCHING PAPILLAE are

characteristic Orphan-Annie nuclei

Local invasion invading trachea, RLN. Propensity to spread to the cervical

lymph nodes. Distant spread to bone, lungs.

Second most common (20%) Iodine deficient areas 3 times more in women Presents more advanced in stage than

papillary Late 40’s

Pathology: round, encapsulated, cystic changes, fibrosis, hemorrhages.

Microscopically, neoplastic follicular cells.

Differentiated from follicular adenomas by the presence of capsule invasion, vascular invasion.

Cannot reliably diagnose based on FNA.

Local invasion is similar to papillary cancer with the same presentation.

Cervical metastases are uncommon. Distant metastases is significantly

higher (75%), with lung and bone most common sites.

A variant of follicular, also known as oncocytic carcinoma. More common in women than men, presents in 5th decade of life. Cannot diagnose on FNA Does not take up iodine, so treat

aggressively. Thyroid suppression and radioiodine don’t

work.

5%, female preponderance 75% sporadically, 25% familial. Familial

cases are usually all over the gland, sporadic usually not multifocal.

MEN 2A, MEN2B and FMTC syndromes. Arises from parafollicular cells

Highly lethal form of thyroid cancer Median survival <8 months 10% of all thyroid cancers Affects the elderly 30% of thyroid cancers in patients >70

years 53% have previous benign thyroid

disease

Pathology Classified as large cell or small cell Large cell is more common and has a worse

prognosis Histology - sheets of very poorly

differentiated cells little cytoplasm numerous mitoses

necrosis extrathyroidal invasion

MEN 2a is Sipple syndrome MTC, pheochromocytoma, hyperparathyroidism.

MEN 2b is MTC, pheo, ganglionomas. FMTC is just MTC Medullary cancer in these are most

aggressive, younger age, rapid growth and metastases.

Sporadic painless nodule, symptoms of invasion.

Controversy regarding extent of therapy continues.

Surgical excision whenever possible. Total thyroidectomy has been

mainstay (all apparent thyroid tissue removed).

After surgery, perform radioiodine scan, ablation if residual disease or recurrence.

Radioiodine targets residual thyroid tissue and tumor after thyroidectomy.

Given in diagnostic doses and therapeutic doses to ablate tissue.

Maintained on thyroxine after surgery and ablation. Low TSH levels reduce tumor growth rates and reduce recurrence rates.

Most recommend TSH levels of 0.1 mU/l. Follow-up q 6 months with thyroglobulin

levels and repeat scans. Thyroglobulin is good because well

differentiated tumors produce it.

Suspicion for malignancy Compressive symptoms Cosmetic issues Patient wishes Well-differentiated thyroid carcinoma in

low risk patient (controversial)

Thank You !