thyroid neoplasms
TRANSCRIPT
Thyroid Neoplasms
Benign1. Adenoma
•Follicular – colloid, embryonal,foetal
•Hurthle cell
2. Teratoma
Thyroid NeoplasmsMalignant Tumours: 1. Well differentiated
Papillary Follicular Hurthle cell 2. Undifferentiated Anaplastic 3. Medullary carcinoma
Thyroid neoplasms
Lymphomas Hodgkin`s lymphoma NonHodgkin`s lymphoma Others Squamous or Mucinous
carcinoma Secondaries
Aetiology of Thyroid carcinoma
Molecular Biology RET – oncogene Papillary ca. & medullary carcinoma ras mutations in follicular ca. P53 mutations in anaplastic
ca.
Aetiology of thyroid ca
Radiation
Iodine excess/ deficiency
Pap Ca 60%
Foll Ca 17%
Anaplastic 13%
Medullary 6%
Lymphoma 4%
Incidence 3.7/100000
Females more affected
3:1
Mortality 2-3%
Papillary carcinoma Most common – 60 to 70%. Least aggressive cancer. Prolonged course. 3rd and 4th decades of life. More common in women. Predominant thyroid cancer in children.
Pathology Grey white poorly defined nodule
varying in size from a few mm. To several cms.
In large lesions, haemorrhage, necrosis and cyst formation with visible papillae may be seen.
Pathology - Microscopy Typical papillary structures Optically clear nuclei called Orphan
Annie nuclei Round laminated calcified bodies –
psammoma bodies. Nuclear grooves,lobulations and
atypia
pathology Multiple foci in same lobe
Sometimes opposite lobe
Intrathyroidal lymphatic spread/
Multicentric growth
Pathology They grow slowly and tend to
metastasize to lymph nodes Better prognosis than other forms
of thyroid cancer Tendency to more malignant
growth with advancing age Local spread to trachea,recurrent
laryngeal nerve and oesophagus
Occult carcinoma Papillary CA less than 1.5 cm
Palpable LN
Jugular chain
Primary may be only few mms size
Clinical Features Solitary Nodule (STN) Dysphagia,dyspnoea,hoarseness
indicate locally invasive disease Lymph node enlargement Occasionally lymph node
enlargement alone
Investigations Thyroid function tests Ultrasound scan Isotope thyroid scan Fine needle aspiration
cytology
Treatment Near total/total thyroidectomy Lobectomy/Hemithyroidectomy Modified neck dissection TSH suppression
Total thyroidectomy
hemithyroidectomy
Thyroid suppression 0.1-0.2 mg daily
Suppress endogenous TSH
Not very much useful in follicular Ca
Thyroglobulin Tumour marker
Obviate the need of serial isotope scanning
Only adjunct to clinical examination
Follicular carcinoma Occurs in the fifth decade More common in females 15% of thyroid malignancies Occurs more frequently in iodine
deficiency areas More aggressive and dangerous Blood stream spread
Pathology Tumour is well encapsulated . Haematologic spread
Microscopy
Follices are crowded with cells with hardly any colloid.
Capsular and vascular invasion are prominent features.
Tumour with large cells with abundant eosinophilic cytoplasm are called Hurthle cell carcinoma
Clinical features Solitary nodule or multiple painless
nodules May arise in a long standing goiter Lymph node involvement rare Haematogenous spread to bones
lungs or liver Bony metastasis may be pulsatile
Investigations FNAC not helpful Radiology - X –ray chest , neck,
bones, CT scan Raio isotope scan
Treatment Total thyroidectomy/Near total
thyroidectomy Radioiodine External beam radiation Chemotherapy TSH suppression
Prognosis of DTC Age
Histological variant
Extra thyroidal spread
size
Low risk Men<40, women<50 Older patients - intrathyroid papillary Ca -foll with minor caps.
Invasion -<5cm -no distant mets
High risk Distant mets
Older patients - extra thyroidal Pap - major caps.invasion - >5 cm
2% mortality in 25 yr survival in low risk group
46% in high risk group
Medullary carcinoma(MTC) Arises from the C – cells ,derived from the neural crest
– APUD system Sporadic or familial form
Familial MTC Familial with MTC only
with MEN IIA – MTC hyperparathyroidism
& phaeochromocytoma
MTC secretes calcitonin CEA, histamine,and serotonin
Pathology Sporadic form – usually unilateral,
familial form – multinodular Sheets of infiltrating malignant
cells with areas amyloid Special staining can be performed
for calcitonin in the cells Lymphatic & haematogenous
spread
Clinical features Age – sporadic form (80%) 40 – 60
yrs. Familial (20%) – younger age group
Single nodule (sporadic) , multinodular (familial)
Lymph node enlargement +(- ) Dysphagia ,dyspnoea hoarseness MEN IIA - symptoms of
hyperthyroidism or phaeochromocytoma
Investigations FNAC OF Thyroid mass Urinary metabolites –
VMA,metanephrine,catecholamine Serum Calcium USG Abdomen Serum calcitonin
Treatment Total thyroidectomy with central
neck dissection External – beam radiotherapy in
unresctable disease
Anaplastic thyroid carcinoma Rapidly growing tumours with
invasion of surrounding structures Lymph node involvement is
frequent & early Foci of both undifferentiated and
differentiated cells are seen in follicular or papillary pattern
Clinical features Presents with rapidly progressive
lump of short duration May be painful or ulcerated Compressive symptoms+ Mass hard and fixed to the
surrounding structures Stridor+ Metastasis lymph nodes,
liver ,lungs. bones
Treatment FNAC – diagnostic Treatment – disappointing Debulking , tracheostomy
radiotherapy
Secondaries Breast
Colon
Kidney
Melanoma
hypothyroidism Commonest endocrine problem
5% of female population affected
Types Primary
Secondary
tertiary
Primary Auto immune
Surgery
Radioactive iodine
Ext.beam RT to neck
drugs
Hashimoto’s thyroiditis Auto immune
Familial
Females 9:1
40-50 yrs
features Compensated hypothyroidism
Hyperthyroidism
hypothyroidism
TSH
ANTIBODIES antimicrosomal antiTG
Treatment
Normalise the TSH
Complications Other autoimmune disorders
lymphoma