Cancer 4 Flashcards
What is Thyroid cancer ?
Cancer in the Thyroid gland
4 TYPES
0 Medullary - 3rd less common -
arise from C cells - can seen in upper 1/3rd of medulla - mutation - usually unilateral
(can be inherited - familial medullary TC ) - can be multiple tumors across both lobes.
- causes C cells to produce excessive Calcitonin
o can also release serotonin & Vasoactive intestinal peptide (increase gastrointestinal motility)
0 Anaplastic - rarest, most aggressive - cells are very abnormal - very mutated
DIFFERENTIATED THYROID CELLS
0 Follicular - 2nd most - associated with low dietary iodine - invade nearby blood vessels spread around body - not really invade lymph nodes.
- Hurthle cell carcinoma - variant of Follicular - follicular cells increase mitochondria in response to inflammation - granular appearance - cells also seen in Hashimotos.
0 Papillary - most common form of TC - associated with radioactive exposure during childhood & mutations.
(name - cells have papillae that grow slowly towards lymph nodes and invade them)
(differentiated cancer - arises from follicular cells - cancer cells act & look like normal thyroid cells
RISK FACTORS
- ## Female
Signs & symptoms of TC ?
- RISK FACTORS
SIGNS & SYMPTOMS
- front neck lump - painless(hard and immovable )
- cervical lymphadenopathy - metastasis.
- Sore throat - not improving
- unexplained hoarseness (not improving after weeks. )
- unexplained dysphagia
(due to esophagus compression) - Unexplained dyspnoea - tracheal compression.
- tracheal deviation - can by cancer or benign goitre.
Medullary thyroid Carcinoma
0 Diarrhea - (due to Vasoactive intestinal peptide secretion)
0 Flushing of skin - Serotonin secretion
- TC usually non - functional - dont cause hypo or
hyperthyroidism.
(cold nodule / tumour - means non functioning )
RISK FACTORS
- Female
- Neck irridation
- age - most common btw 30 -40 -early adulthood.
extremes of age - more likely ( <14 or >70)
o Anaplastic - most common over 65 yrs.
-Family history of TC (especially medullary)
What is Multiple Endocrine negationsoplasia ?
Presence of multiple Tumors in endrocrine glands - (at least 2)
- can be malignant or cancerous
TYPES
Type 1 - most common - tumours in : - Parathyroid - Pituitary - Pancreas (Glands) - overproduction of hormones ) e.g Hyperparathyroidism - Calcium excess - kidney stones, thin bones, N & V , hypertension etc.
Type 2 - medullary Thyroid Cancer
o Type 2A - plus Phaecochromocytoma (P) (adrenal gland tumour) + Hyperparathyroidism (HPT - only occurs in type 2A)
o Type 2B - plus (P) , +Neurofibromas / neuromas (beingn growths on nerves ) = marfanoid features (-Found in marfan habitus -(not marfan syndrome -just look like you do- long arms , etc. )
o FMTC - Familial medullary TC
Type 3 - TYPE 2B
Type 4 - similar Type 1 - just mutation caused by different gene.
Investigations of Thyroid Cancer ?
TSH - normal in TC
(rule out Hyperthyroidism - as TSH will be low in primary - High T3 & T4 - negative feedback loop
Hyperthyroidism suggest HOT/HYPERFUNCTIONING NODULE -LOW CHANCE )
Ultrasond - neck
(look out for :
o irregular shape ( taller than normal / borders)
o micro- calcifications
Fine needle Biopsy - done if TSH not suppressed - tell which type it is .
Laryngoscopy
- may show paralysed vocal cord
To consider
0 Free T3 & T4 - normal
0 Thyroid scan & Uptake (if increased - hot nodule - hyper functioning )
0 Core biopsy - if Thyroid Lymphoma suggested - can confirm this.
0 CT - neck - cervical lymphadenopathy
0 Genetic testing for familal syndormes.
0 Serum Calcitonin - high in medullary cancer - C cells.
Treatment of TC ?
Dependent on type
Differeniated TC - all types
0 1st line
- Surgery - Total or Hemithyroidectomy (hemi - if low risk)+ Radioactive iodine Ablation (RIA) + TSH supression
RIA - radioactive iodine given to destroy remaining cancer cells ew weeks after surgery.
(as used for recurrent disease )
TSH suppression with T4 (levothyroxine) - TSH - growth factor for TC - with
recurrent / metastatic - RIA + TSH supression +/- (surgery if surgically resectable )
2nd line
- Sorafenib
- Lenvatinib
(Kinase inhibitors - block abnormal protein cause cancer cells to grow)
- used if cancer refractory to radioactive iodine.
MEDULLARY
0 1st line
Surgery - Total Thyroidectomy +/- central neck lymph node dissection / radical neck dissection.
ADJUNCT - Thyroid placement (rather than TSH supression as medullary cancer is not TSH sensitive - Levothyroxine - T4 - negative feedback loop - lowers TSH)
2nd line
Vandetanib (tyrosine kinase inhibitor )
CONTRAINDICATED - Long QT syndrome.
ANAPLASTIC -
1st line
- Pallative surgery (total T ) + Chemoradiation.
(adriamycin- or platinum-based chemotherapy plus radiation)
ADJUNCT - Thyroid replacement
LYMPHOMA
1st line
- Chemotherapy + external radiation.
Thyroid lymphoma
Type of TC
Lymphoma that arises from Thyroid glands.
-
Are Non - Hodgkin Lymphomas - almost always
Linked with autoimmune conditions i.e Hashimotos
(immune component - results chronic proliferation of lymphoid tissue —-> then undergoes mutation —–> lymphoma).
Lymphoma - cancer in Lymphocytes.
SIGNS -
rapidly enlarging painless neck mass
- compressive symptoms
- Hx of chronic Lymphocytic thyroidits
investigation
- TSH - normal
- Ultasound
- Fine needle aspiration - abdunant lymphocytes - have to distingiush btw chronic thyroiditis.
Differential diagnosis of TC?
Colliod nodule / Colliod nodule Goitre - enlargement of thyroid tissue
0 Thyroid adenoma / hyperplastic nodule - cold nodule
or Toxic Adenoma - hot - produce hormone - cause hyperthyroidism
0 non - toxic multinodular goitre - enlargement caused by nodules (lumps on thyroid )
or Toxic multinodular goitre
0 Diffuse goiter - enlargement of whole gland.
0 Thyroid cyst
(commonly formed from degenerating adenomas)
0 Thyroiditis
0 Graves disease
0 Benign enlarged parathyroid gland
0 Parathyroid cancer
0 Metastasis
