Histopathology Endocrine Pathology Flashcards
thyroid Cellular structure
Colloid – filled acini lined by follicular epithelial cells.
Thyroid Secretes
- Hormone thyroxine which is secreted into the blood. The organ is highly vascular for this reason
Thyroid Function
- Regulates basal metabolic rate
Hypothyroidism: Commonest Cause is
Hasimoto’s thyroiditis – chronic lymphocytic thyroiditis
Hypothyroidism: Hasimoto’s thyroiditis is
An autoimmune: anti-thryoid antibodies: lymphocytic destruction of thyroid – leads to a fibrotic scarred atrophic gland.
Hypothyroidism:Epi
F:M = 10:1
Hypothyroidism: Less often caused by
Removal of thyroid
Radioiodine treatment
Hypothyroidism: Symptoms
Myxoedema slowing of the mind and body • Weight gain, constipation • Cold intolerance • Tiredness, depression • Big tongue, deep voice (deposition of matrix substances in viscera and skin) • Thin Hair • Weak Heartbeat + low BP • Slow reflexes
Hypothyroidism: Histologically
Lymphocytes destroying follicular cells
Reduced colloid in accini
Active inflammation infiltrate
Hyperthyroidism Common causes
85% of cases is Grave’s disease Hyperfunctional multinodular goitre (MNG is usually euthyroid) Hyperfunctional adenoma (benign follicular tumour) - rarely
Hyperthyroidism Description
Increased basal metabolic rate
Hyperthyroidism Symptoms
- Sweating, heat intolerance
- Weight loss despite incd appetite, diarrhoea
- Tachycardia, arrhythmias (often AF)
- Tremor, anxiety, hyperactivity, brisk reflexes
- Staring gaze, lid lag, exophthalmos
Graves’ disease (diffuse toxic goitre) Epi
F:M = 10:1
Graves’ disease (diffuse toxic goitre) Description
Autoimmune
Graves’ disease (diffuse toxic goitre) Caused by
Thyroid-stimulating autoantibodies (overdrive increased thyroxine production)
Graves’ disease (diffuse toxic goitre) Presentation
Symmetrical enlargement of thyroid – often a bruit can be heard as there is a vast increased in blood flow
Graves’ disease (diffuse toxic goitre) Exopthalamos due to
Deposition of connective tissue behind the eyeball = pushed forward
Multinodular goitre: Description
Usually euthyroid
Large goitre may cause tracheal compression or dysphagia/stridor
Cosmetic effects
Multinodular goitre:
Causes
Due to iodine deficiency and other reasons.
Endemic in some developing countries w/ chronic iodine deficiency.
Adenoma (follicular): Description
Benign tumour Usually euthyroid (not overactive) Rarely hyperfunctional (toxic nodule)
Adenoma (follicular): Treatment
Thyroid lobectomy (can survive with on elobe4)
Carcinoma of the thyroid: Types and incidence
- Papillary – 80%
- Follicular – 15%
- Anaplastic – 2%
- Medullary – 3%
Carcinoma of the thyroid: Epi
Female predominance of most types
20-30 yrs old
Papillary carcinoma
Spread via lympatics
Indolent, often cystic, may be multifocal.
Good prognosis
Papillary carcinoma description
Papillae covered by epithelial cells with pale, empty nuclei; psammona bodies
Vesicular appearance.. Cystic (fluid filled)
Well defined lesion
Papillary carcinoma Classical presentation
35 yr old woman presents with enlarged cervical lymph nodes: metastatic carcinoma]ultrasound showed a thyroid tumour
Resected thyroid gland: papillary carcinoma.
Papillary carcinoma Risk association
Radiation is associated with papillary carcinoma - chernobyl
Papillary carcinoma Follicular carcinoma description
Widely invasive. Spreads via bloodstream with metastases to lungs/liver/bones/brain
Papillary carcinoma Follicular carcinoma epi
30-50 yrs
Poorer prognosis due to spread via blood stream
Papillary carcinoma Clinical presentation example
45 yr old
Pathological fractures
Metastatic
Anaplastic carcinoma
Elderly patients
Aggressive – local invasion, metastases
No response to treatment
Fatal in a few months
Adenoma carcinoma histology
Spindly shaped tumour cells
Osteoclast like multinucleated → not cancer just reacting to process
Medullary Carcinoma arises from
C cells of thyroid,, which secrete calcitonin (calcium metabolism)
Medullary Carcinoma tumour type
Neuroendocrine tumour
Medullary Carcinoma histo
- Amyloid carcinoma – combination of epithelial proliferation and stromal changes in medulla.
- Calcitonin present in tumour (brown stain = positive cells)
Medullary Carcinoma Epi/associated with
Sporadic: 70%
MEN 2A,2B or FMTC: 30%
Medullary Carcinoma Diagnostic test
Ret oncogene = overativity of the MEN 2A, 2B