Carcinoma of thyroid

Carcinoma of thyroid

Carcinoma of thyroid

CARCINOMA THYROID


INCIDENCE
0.6 & 1.6% of cancers among men and women

PRESENTATION 

  • As Carcinoma
  • Solitary nodule
  • As Nodular Goitre

RISK FACTORS

  •     Radiation and Cellular oncogenes (kras, ret)
  •     TSH hypersecretion may stimulate its growth
  •     Thyroid nodule in a child
  •     Pre-existing Thyroid disease
  •     Familial – Gardners, Men II, Cowdens
  •     Iodine
  •     Hormonal factors

HIGH AND LOW RISK GROUPS
A    Age
G    Histologic Grade
E    Extent of Tumour
S    Size
R    Uptake of Radioactive Iodine
A    Increased Adenyl cyclase response to TSH
P    Ploidy Or DNA content of tumour
E    EGF receptors and extent of Treatment

PROGNOSTIC CRITERIA
AGES ( Mayo  Clinic)
AMES (Lahey Clinic)
DAMES
MACIS ( Metasasis,Age, Completeness,Invasion Size )

     CARCINOMA THYROID
 

CLINICAL STAGING

  • Localised to Thyroid Gland
  • Localised to Thyroid Gland + Mobile Nodes
  • Direct Local invasion or fixed cervical nodes
  • Metasatses

CLASSIFICATION
1. Well Differentiated
A. Pure Papillary Carcinoma , Mixed Papillary and Follicular
B. Follicular Carcinoma minimally invasive encapsulated widely invasive, Angionvasive Carcinoma
C. Hurthile Cell Carcinoma
2. Undifferentiated
Spindle Cell, Giant Cell, Small Cell etc.
3. Arising from Parafollicular cells
Medullary Carcinoma Thyroid
4. Lymphoma
5. Squamous Cell Carcinoma,Teratoma,Sarcoma
6. Metastatic Carcinoma
TNM CLASSIFICATION
T1    –    Single Tumour less than 1 cm
T2    –    Single or Multiple Tumours – Producing deformity < 4 cm
T3    –    > 4 cm
T4    –    Beyond the Thyroid Gland
N1    –    Movable Homolateral nodes
N2    –    Movable contralateral nodes
N3    –    Fixed nodes
M1    –   Metastases

PAPILLARY TUMOUR  CLASSIFICATION
Occult  (< 1.5 cm)
Intra Thyroidal
Extra Thyroidal

Note : Multifocal 20% on inspection 85% histology
Lymph node metastases do not appear affect prognosis

 
OPERATIVE STRATEGY ( PAPILLARY CARCINOMA )
Clinically unsuspected Micro Carcinoma    –   No Further Resection
Occult primary Carcinoma of Thyroid         –   Conservative surgical treatment
Intra Thyroidal and invasive extra Thyroidal –   Total with +/- Modified neck dissection
Solitary nodule  – Always use Frozen section biopsy
FOLLICULAR CARCINOMA – FEATURES
Solitary
Encapsulated
Solid
Pinkish red cut surface
Microfollicules with varying proportions of solid masses cells
Capsular and vascular invasion may be present
OPERATIVE STRATEGY (FOLLICULAR CARCINOMA )
Total Thyroidectomy with I -131 ablation of Thyroid tissue
HURTHLE CELL CANCERS
Follicular cell origin
Oxyphilic cell tumour
Oncocytoma
Aakanaszy cell tumour
Bilateral  – Spread to regional nodes
Do not take up radioactive iodine
Total  Thyroidectomy treament of choice
EFFECTS OF TOTAL THYROIDECTOMY
Decreases possibility of tumour differentiation
Decreases possibility of recurrent cancer in central neck
Allows for follow up with thyroglobulin
Removes all intra thyroidal tumour
 HISTOLOGICAL SURPRISE
Sub-total thyroidectomy  – Biopsy result – malignant :

  • If total Lobectomy side Malignant – I –131 Ablation of the remnant side
  • If subtotal side Malignant  – Completion thyroidectomy

RADIO IODINE TREATMENT INDICATIONS
Need to treat remnant normal thyroid
Treatment of residual thyroid cancer
For Nodal disease
For pulmonary metastasis
For skeletal metastasis

Patient is allowed to become hypothyroid 4 – 6 weeks post op.
I -131 Scan done
30 -100 Mill Curies can be given to ablate residual or metastatic disease
Scans are repeated at six monthly intervals till 2 consecutive scans are negative.

EXTERNAL RADIOTHERAPY INDICATIONS
Gross residual tumour following incomplete resection
Concentration at site of macroscopic/microscopic disease
Large tumour with extra thyroidal disease 
Poor histological variety
Age > 50 Years

LYMPHOMA  THYROID
Associated with Hashimoto’s thyroidtis 
B Cell origin
Intracytoplasmic monoclonal, immunoglobulin and lymphocytic antigens help in differntiating from small cell carcinoma
Chemotherapy + Radiotherapy is a good treatment option

ANAPLASTIC CARCINOMA
10% spreads early into adjacent structures by direct invasion & blood spread
Common in sixth to seventh decade
Patient usually succumbs within 36 months
Surgery or debulking if possible
Operate normal side first
Radiotherapy & Chaemotherapy used

MEDULLARY CARCINOMA OF THYROID
May be :

1.SPORADIC (Usually Unlateral)
2. HERIDATARY (Multifocal   or Bilateral – Autosomal Dominant)

  • Familial MCT
  • Associated with MEN
    • MEN II A  (Pheochromocytoma + Parathyroid Hyperplasia)
    • MEN II B (Pheochromocytoma +  Mucosal Neuromas)

MEDULLARY CARCINOMA OF THYROID
Thyroid swelling (74 – 85%)
Cervical Lymphadenopathy( 25 – 63%)
Pressure Symptoms
Disseminated disease
Diarrhoea
MANAGEMENT OF PERSISTENT AND RECURRENT HYPERCALCITONINEMIA
Plasma Calcitonin levels are  a sensitive mareker for Medullary carcinoma thyroid
Persistant hypcaltoninema after surgery for medullary carcinoma thyroid is not uncommon and does not necessarily indicate recurrent disease.

MEN IIA
Medullary Carcinoma Thyroid
Pheochromocytoma
Hyperparathyroidism

MEN IIB
Medullary Carcinoma Thyroid
Pheochromocytoma
Mucosal Neuromas, Marfanoid Habitus, Ganglio neuromatosis

MEDULLARY CARCINOMA OF THYROID – TUMOUR MARKERS
Serum Calcitonin
Normal (<300 pg/ml)
Abnormal (> 1000 pg/ml)
Role:
Pre OP  –  ?
Screening
Post OP – Follow up
CEA
MEDULLARY CARCINOMA OF THYROID – SURGICAL MANAGEMENT
(I) Prophylactic Central Neck Dissection
Reasons : High incidence of Lymph node involvement (50%)
Extent:
Above       Hyoid bone
Below       Braciocephalic vein
Lateral      Carotid sheaths

(II) Total Thyroidectomy
Reasons: > 90% Of Familial & > 20% Of Sporadic are Multicentric or Bilateral
MEDULLARY CARCINOMA OF THYROID LYMPH NODE DISSECTION
Modified Neck Dissection
Indications :
> 2cm Size jugular paratraclea node
Histology consistant with nodal metastasis after CND
NON SURGICAL APPROACHES
Non surgical approaches to MTC Treatment have generally met with limited success
MIBG
External Radiotherapy
Dacabazine, Cyclophophamide vincristine
STAGING, RATING, SCHEMES, DEFINING RISK FACTORS EORTC – Age, Sex, Cell Type, Extension, Metastases AMES  – Age, Sex, Size, Extension,Metastases AGES  – Age, Size, Grade, Extension MACIS – Metastases, Age, Completeness of resection invasion, Size
CONCLUSIONS

 

  • Large group of well differntiated neoplasms slow growth and high curability
  • Small group of highly anaplastic tumours with fatal outlook
  • Five broad classified groups
  • FNAC and  TSH are very useful
  • Total thyroidectomy the operation of choice

 

 


Prof.: Aravindan Nair M.S.MNAMS
HOD General Surgery, CMC, Vellore,
E.Mail : [email protected]

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