Endo-thryoid pathology Flashcards
features of anaplastic carcinoma of thyroid
- rare, undifferentiated malignant tumor of the thyroid
- population: elderly
- highly aggressive -poor prognosis (die within year of local invasion)
- local invasion presents with mass effect (dysphagia , SOB)
- gene mutation: TP53
- microscopy shows areas of papillary carcinoma with high -grade tumor (poor differentiation and necrosis)
which population is most likely to get the tall cell variant of PTC and how does it act?
older patients
aggressive
features of medullary thyroid carcinoma
- amyloid (calcitonin deposits within tumor as amyloid)
- high levels of calcitonin (hypocalcemia)
- c-cell hyperplasia (seen with immunostain)
- blue cells with dispersed chromatin
- +congo red stain and apply green biferengence
clinical features of hashimotos
- initial hyperthyroidism (hashitoxicosis)
- progression to hypothyroidism (low T4, high TSH)
- diffuse PAINLESS enlargement of gland (goiter)
histo of the thryroid
- pools of pink colloid
- follicular cells ( produce TH)
- parafollicular C-cells (produce calcitonin)
follicular variant of PTC
- follicular architecture , but have the Orphan annie eye nuclei
- fewer associations with RET-PTC and BRAF
- more associated with RAS and PTEN mutation (like follicular CA and adenoma)
most common malignant tumor of the thyroid gland?
papillary thyroid carcinoma
actions of TH on the body
- essential action: increase in (BMR) basal metabolic rate
- liver: increase gluconeogenesis/fat & cholesterol synthesis/bile acid conversion from cholesterol
- adipose: increase fatty acid mobilization
- heart: increase HR and hypertrophy
- pituatary: decrease TSH, increase GH
- muscle: increase protein breakdown/ fat oxidation/ glucose utilization
- bone: increase growth and resorption
define apathetic hyperthyroidism
older adults with masked symptomatology
- unexplained weight loss
- cardiovascular disease
define cretinism
hypothyroidism in neonates and infants (congenital) usually caused by iodide deficiency during gestation (or result of genetic alteration in normal thryoid metabolic pathway)
-sx: mental retardation, growth retardation, coarse facial features, enlarged tongue, umbilical hernia
is primary or secondary hyperthyroidism more common
primery thyrotoxicosis
example of secondary is pituitary adenoma
define myxedema
hypothyroidism in older children or adults
- clinical features based on decreased BMR and SNS activity
sx: - myxedema ( accumulation of glycosaminoglycans in the skin and soft tissue resulting in deepining of voice and enlarged tongue)
- weight gain
- slowing mental/physical activity (“sluggish)
- muscle weakness
- cold intolerance/decreased sweating
- bradycardia, low Cardiac output –> SOB, fatigue
- oligomenorrhea,
- hypercholesterolemia
- constipation
average age of papillary thyroid carcinoma dx? usual presentation? major risk factor? histo? gene mutation?
age: 25-50yo
- usually no sx (palpable nodule; get US)
- RF: exposure to ionizing radiation in childhood
histo: papillae lined by cells with clear “ORPHAN ANNIE EYE” nuclei and nuclear grooves, often associated with psmammoma bodies
- gene: RET-PTC mutation, BRAF gof mutation
* common to spread to cervical LN but prognosis is excellent
define riedel thyroiditis
chronic inflammation of the thyroid gland with extensive fibrosis of the gland (extends from thyroid into adjacent tissues)
- IgG4-related disease
- presents as hypothyroidism with “hard as wood” nontender thryoid gland , and euthyroid levels
- histo: fibrosis, lymphocytes, PLASMA CELLS
- *clinically mimics anaplastic carcinoma but patients are younger (40s) and malignant cells are absent
hallmark of IgG4 related diseases ? examples?
fibrosis
IgG4+ plasma cell infiltrate
(causes epithelial damage and organ damage)
examples: Riedels thyroiditis, autoimmune pancreatitis, sclerosing mediastinitis, idiopathic retroperitoneal fibrosis
what is hashimotos thyroiditis (most common cause of hypothyroidism in iodine adequate areas)
autoimmune destruction of thyroid gland–> hypothyroidism
- autoantibodies againt thyroglobulin and thyroid peroxidase (TPO)
- HLA-DR5 associated