2. Endocrine gland – lower
part of neck
Extend – oblique line of
thyroid to 5th or 6th
tracheal rings
Consists – right & left lobes
joined by isthmus
Capsules – true & false
ANATOMY
4. PHYSIOLOGY-
The primary physiologic role is the production of thyroid hormone,which plays an important role in metabolic homeostasis.
A secondary role is the production of calcitonin, a hormone involved in calcium homeostasis.
The follicular cells of the thyroid gland synthesize and secrete thyroglobulin(Tg) and thyroid hormone in two biologically active forms,
thyroxine (3,5,3′,5′ iodothyronine or T4) and
triiodothyronine (3,5,3′ iodothyronine or T3).
T4 is considered the storage and transport form of the hormone and T3 is considered the metabolically active form.
11. Clinical features …..
o Compression features are less common
o Metastasis to cervical lymph node
o Microcarcinoma < 1cm
o Young females (20-40 years)
o soft / hard / firm ,solitary / multifocal
swelling
13. 10% of thyroid carcinoma
Common in women & older age group(40-60yrs)
Distant metastasis through blood into
bones,lungs & liver
Bone secondaries – vascular, warm, pulsatile
commonly in skull, long bones & ribs
Most common presenting feature – solitary thyroid nodule
14. Morphology
Minimally invasive – grossly
encapsulated
Widely invasive – may be
unencapsulated
• Capsular & vascular invasion
15. CLINICAL FEATURES . . .
solitary thyroid nodule - firm/ hard
Stridor – tracheal compression / infiltration
Dyspnoea, hemoptysis, chest pain –
lung secondaries
Hoarseness of voice – recurrent laryngeal nerve
involvement
F : M = 3: 1
16. Hurthle cell Carcinoma
-more aggressive variant of follicular ca.
-contain oxyphil cells
-They secrete thyroglobulin
-metastasize to local lymph nodes
-potentially malignant.
22. TNM Staging
NODES
N0 – No regional node metastasis
N1a – level VI
N1b – any other levels
METASTASIS
M0 – No metastasis
M1 – metastases present
23. Stage Under 45 yrs Over 45 yrs
I Any T, any N, M0 T1 , N0, M0
II Any T, Any N, M1 T2, N0, M0
III T3/T1, T2 & N1a M0
IVA T4/T1,T2,T3T4a& N1b, M0
IVB T4b, Any N, M0
IVC Any T, Any N, M1
25. Total thyroidectomy recommendations-
If the papillary thyroid carcinoma is >1 cm
Follicular adenoma > 4cm
Multifocal disease
Regional or distant metastases are present,
The patient has a personal history of radiation therapy to the
head and neck
The patient has first-degree family history of DTC.
Older age (>45 years) – near-total or total thyroidectomy
- tumors <1–1.5 cm
Surgical Treatment
26. Hemithyroidectomy
small (<1 cm),
low-risk,
unifocal,
absence of
• prior head and neck irradiation
• radiologically or clinically involved cervical nodal
metastases.
27. Lymph Node Dissection
Therapeutic central-compartment (level VI) neck dissection - clinically
involved central or lateral neck lymph nodes
Prophylactic central-compartment neck dissection (ipsilateral or
bilateral) – advanced papillary thyroid carcinoma (T3 or T4).
Not needed small (T1 or T2), noninvasive, clinically node-negative PTCs
and most follicular cancer.
The sodium iodine symporter (NaIS) actively transports sodium and iodine against an electrochemical gradient across the cell membrane in an energy-dependent fashion.
This transmembrane protein is stimulated by thyroid-stimulating hormone (TSH or thyrotropin).Functional NaIS is present on malignant follicular cells seen in multiple variants of differentiated thyroid cancer.
The unique ability to concentrate iodine within these malignant cells makes radioactive iodine (RAI) a potent targeted therapy.
