Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 57 Thyroid Neoplasms PPT-Powerpoint Presentations and lecture notes
Thyroid Neoplasms
Dept. of Surgery
Introduction
? Six deaths per 1 million people occur annually.
? Occurs in about 40 per 1 million people per year
? The most common endocrine malignancy
? Accounts for 95% of all endocrine cancers
? Female to Male Ratio 2.5:1
Thyroid Neoplasms
Primary Tumours
? Epithelial
? Malignant Lymphomas
? Mesenchymal tumours
Metastatic Tumours
Epithelial Thyroid Neoplasms
? Tumours of follicular cells
? Benign (adenomas)
? Follicular adenoma
? Malignant (carcinomas)
? Follicular carcinoma (10-20%)
? Papillary carcinoma (75-85%)
? Undifferentiated (anaplastic) carcinoma (<5%)
? Tumours of C-cells
? Medullary thyroid carcinoma (MTC - 5%)
Risk Factors for Thyroid Cancer
The only wel -established risk factor for differentiated thyroid
cancer is head and neck Radiation,especial y during infancy
Papil ary thyroid carcinoma may occur in several rare inherited
syndromes, including familial adenomatous polyposis,
Gardner's syndrome, and Cowden's disease
Patient's Age and Gender
? Malignancy more common in children and adults >60
? Men
Follicular Carcinoma
? Second most common form, 10-20%
? Females > Males, average age = 45 - 55 yr
? Rare in children
? Solitary nodule, painless, cold on isotopic scan
? 50% 10 yr survival Vs 90%10 yr survival
? Haematogenous route is preferred mode of spread
Follicular Carcinoma
? Solitary round or oval
nodule
? Thick capsule
? Composed of follicles
? Capsular invasion or
vascular invasion
within or outside
capsular wall
Papillary Carcinoma
? Commonest thyroid malignancy, 75-85%
? Female:Male = 2.5:1
? Mean age at onset = 20 - 40 yr
? May affect children
? Prior head & neck radiation exposure
? Indolent, slow-growing painless mass cold on isotopic scan
? Cervical lymphadenopathy may be presenting feature
Papillary Carcinoma
? Variable size
(microscopic to
several cm)
? Solid or cystic
? Infiltrative or
encapsulated
? Solitary or multicentric
(20%)
Papillary Carcinoma
Nuclear Features
? Optically clear (ground
glass, Orphan Annie)
nuclei
? Nuclear
pseudoinclusions or
nuclear grooves
Papil ary Carcinoma Prognosis
Excellent but following factors play important role:
? Age and sex
? Size
? Multicentricity
? Extra-thyroid extension
? Distant metastasis
? Total encapsulation, pushing margin of growth & cystic
change
Anaplastic Carcinoma
? Rare; < 5% of thyroid carcinomas
? Highly malignant and general y fatal < 1yr.
? Elderly 65 yrs; females slightly > males
? Rapidly enlarging bulky neck mass
? Dysphagia, dyspnoea, hoarseness
Anaplastic Carcinoma
? Large, firm, necrotic mass
? Frequently replaces entire thyroid gland
? Extends into adjacent soft tissue, trachea and oesophagus
? Highly anaplastic cell on histology with:
? Giant, spindle,small or mix cell population
? Foci of papillary or follicular differentiation
Anaplastic Carcinoma
? Cellular pleomorphism
? +/- multinucleated
giant cells
? High mitotic activity
? Necrosis
Medullary Thyroid Carcinoma (MTC)
? Malignant tumour of thyroid C cel s producing Calcitonin
? 5 % of al thyroid malignancies
? Sporadic (80%)
? Rest in the setting of MEN I A or B or as familial without
associated MEN syndrome
Medullary Thyroid Carcinoma (MTC)
Sporadic MTC
? Middle-aged adults
? Female:male = 1.3:1
? Unilateral involvement of gland
? +/- cervical lymph node metastases
? Indolent course with 60-70% 5-yr survival after
thyroidectomy
Multiple Endocrine Neoplasia Types IIA & IIB
? Germ-line mutation in Ret protooncogene on
chromosome 10q11.2
? MEN IIA: MTC, phaeochromocytoma, parathyroid
adenoma or hyperplasia
? MEN IIB: MTC, phaeochromocytoma, mucosal
ganglioneuromas, Marfanoid habitus, other skeletal
abnormalities
Medullary Thyroid Carcinoma (MTC)
? Histology same for
sporadic & familial
? Solid, lobular or
insular growth
patterns
? Tumour cells round,
polygonal or spindle-
shaped
? Amyloid deposits in
many cases
Medullary Thyroid Carcinoma (MTC)
? Amyloid deposits stain
orange-red with
Congo Red stain
Clinical Manifestation
? Most patients are euthyroid and present with a
thyroid nodule
? Symptoms such as dysphagia, dyspnea and
hoarseness usually indicate advanced disease
? Ipsilateral Cervical lymph glands may also be present.
Diagnosis
? Serum TSH
? Fine Needle Aspiration Cytology (FNA)
? High Resolution Thyroid US- helpful in detecting
non palpable nodule and solid versus cystic lesion
? Thyroid Isotope Scanning- to assess functional activity
of a nodule
Fine Needle Aspiration
? Procedure of Choice ? Fast, minimal y invasive and few
risk
? Incidence of False positive: 1%
? Incidence of False negative: 5%
? FNA is not a tissue diagnosis
? Limitation of FNA: cannot distinguish a benign fol icular
from a malignant lesion.
FNA Results of Thyroid Nodule
Staging For Differentiated Thyroid Cancer
In differentiated thyroid carcinoma, several classification
and staging systems have been introduced. However, no
clear consensus has emerged favoring any one method
over another
? AMES system/AGES System/GAMES system
? TNM system
? MACIS system
? National Thyroid Cancer Treatment Cooperative Study
(NTCTCS)
Prognosis
? GAMES scoring (Papil ary & Fol icular Cancer)
? G Grade
? A Age of patient when tumor discovered
? M Metastases of the tumor (other than Neck LN)
? E Extent of primary tumor
? S Size of tumor (>5 cm)
The patient is then placed into a high or low risk
Category
Age for poor prognosis has been raised from 45 to 55 years (AJCC 8th
Edition)
(GAMES)
Prognosis of Thyroid Carcinomas
Papillary
Best prognosis
Follicular
Medullary
Anaplastic
Worst prognosis
H?rthle Cell Neoplasms
? More aggressive than other differentiated thyroid carcinomas
(higher mets/lower survival rates)
? Decreased affinity for I131
? Need to differentiate from benign/malignant
? 65% of tumors > 4cm are malignant
? If malignant, needs total thyroidectomy and I131 with thyroglobulin
assays
? Mets may be more sensitive to I131 than primary
Secondary Tumours
Direct extensions from: larynx, pharynx, oesophagus
Metastasis from: renal cell carcinoma, large bowel carcinoma,
malignant melanoma, lung carcinoma, breast carcinoma
Treatment
The main treatment of papillary carcinoma of the thyroid is
surgical resection.
For lesions <1 cm, there is general agreement in the literature
that lobectomy plus isthmectomy is the appropriate treatment.
For adults with lesions larger than 2 cm, a total thyroidectomy is
favored by most surgeons.
Patients with history of exposure to ionizing radiation of the
head and neck should have total thyroidectomy
Controversies in Treatment
Total Vs Lobectomy
? Controversy exists about the use of total thyroidectomy
versus lobectomy and isthmectomy in adults with a 1-
to 2-cm lesions
? Role of Lymph node dissection also debated
Central Lymph Node Dissection
Central compartment =the region bounded by the
jugular veins, the hyoid bone, and the sternal notch
All central nodes removed at time or procedure
Removal of Central Nodes important in medullary and
Hurthle Cell Ca
? Microscopic spread is high
? Do not take up I131 and cannot be ablated
Lateral Lymph Node Dissection
Diseased nodes lateral to the jugular vein =modified
radical neck dissection
Removal of LN's anterior and posterolateral to the IJV from
the mastoid to the subclavian vessels inferiorly and lateral y
to spinal accessory nerve (Level 2-5)
Sparing the internal jugular vein, spinal accessory nerve,
and sternocleidomastoid muscle
Treatment
Complications of Surgery
Hypocalcemia -devascularization of parathyroid
about 5%, which resolves in 80% of these cases in about 12
months
Recurrent Laryngeal Nerve Injury-either traction
induced or division.
less than 3%
Bleeding
wound hematomas
Postoperative management for
thyroid cancer
Two principles:
? Radioiodine remnant ablation
? Adminstration of Thyroid Hormone
? To suppress TSH and growth of any residual thyroid
? To maintain patient euthyroid
? Maintain TSH level 0.1uU/ml in low risk pts
? Maintain TSH Level < 0.1uU/ml in high risk pts
Postoperative RAI
Recommendations:
? Postoperative remnant ablation for al patients with
differentiated thyroid carcinoma 45 years of age or older
? Those with primary tumor 1.5 cm in diameter or more
? Extrathyroidal disease, whether manifested by direct
invasion through the capsule of the gland or local or
regional metastases.
Radioiodine therapy
The nonsurgical treatment for papillary thyroid
carcinoma is radioiodine (131-I).
Radioiodine has three uses in the postoperative
treatment of patients with thyroid cancer:
? ablation of residual thyroid tissue
? imaging for possible recurrent disease
? treatment of residual or recurrent thyroid cancer
External Beam Radiotherapy and
Chemotherapy
External Radiation required to control unresectable cancer.
Chemotherapy may occasionally be beneficial in patients with
progressive symptomatic thyroid carcinoma that is unresponsive
or not amenable to surgery, radioiodine therapy, or external
radiotherapy
This post was last modified on 08 April 2022