Non Neoplastic Thyroid disease Flashcards
Ectopic or pathologic thyroid may seen anywhere along what pathway in adult life?
thyroglossal duct
Where does the thyroglossal duct begin?
Foramen cecum
Where is lingual thyroid?
Mass in foramen cecum of tongue
How may lingual thyroid present?
dysphagia, dyspnea, dysphonia
Is lingual thyroid rare or common?
Rare, but the most common location of functioning ectopic thyroid
Does lingual thyroid present in the presence or absence of cervical thyroid?
70% associated with abscence of thyroid
Where does thyroglossal duct cyst usually present?
midline between isthmus and hyoid
When does thyroglossal duct cyst usually present?
At birth or childhood
What risks are present with thyroglossal duct cyst usually present?
repeated infection. Big ones can cause obstruction
Are thyroglossal duct cysts hormonally active?
No
Describe substernal goiter. What is it? How does it present?
thyroid tissue that has “dropped” into anterior mediastinum; seen with cervical goiter.
May be symptomatic (dyspnea, dysphagia, hyperthyroid, hypothyroid) or not
A lateral aberrant thyroid is more likely to be what?
metastatic follicular thyroid carcinoma
Describe suprahyoid/infrahyoid thyroid?
Similar location to thyroglossal duct cyst. Often hypothyroid with absent cervical thyroid.
Describe struma cordis
Ectopic thyroid tissue in heart, usually right ventricle. Usually functions and is usually found by accident.
What is struma ovarii?
Monodermal teratoma of ovary, composed mainly (>50%) of adult thyroid tissue
Struma ovarii may functionally cause ____.
thyrotoxicosis
How might struma ovarii presents?
woman with labs showing thyrotoxicosis but normal thyroid on exam, may be small
Is struma ovarii malignant?
Adenomas are common, only 5% are malignant
What hormonal changes are associated with early/late Hashimoto’s?
Early: hyperthyroid
Late: hypothyroid
T or F. 85% of hyperthyroidism is associated with diffuse hyperplasia with Grave’s.
T
How may someone with Grave’s present?
exopthalmos, non-pitting edema, fatigue, weight loss, increased appetite, tachycardia, muscular weakness
Pathophys of Grave’s disease
Immune mediated production of TSH receptor antibodies that cause thyroid stimulation without negative feedback. Binding of Ab to other tissues causes increased GAGs with resultant tissue effects (exopthalmos, myxedema)
How does Grave’s look on histo?
Hyperplastic, too many cells, heaped up epi looking like papillary, scalloped colloid due to vacuoles from increased colloid turn over
_____ is the most common cause of hypothyroidism in north america. _____ is most common world wide.
Hashimotos; iodine insufficiency
What is the automimmune etiology of Hashimotos?
T cell defect
Epidemiology of Hashimoto’s
F:M 10:1-20:1
Hashimoto thyroiditis on histo
There is intense lymphocytic infiltration with tissue destruction and early fibrosis
What is subacute thyroiditis? Epidemiology, pathophys, etc…
Also known as DeQuervain thyroiditis
F:M is 3:1 to 5:1; season peak in summer
Probably a postviral inflammatory process
Not autoimmune, therefore self limited
Mixed inflammatory reaction with prominent giant cell formation.
Describe subacute lymphocytic (painless) thyroiditis
More common in females, without granulomas or giant cells, can be postpartum, may have HLA susceptiblity genes, could be a sub-acute hashimotos
Describe Riedel thryoiditis
Unusual disorder of unknown cause
Characterized by fibrosis of thyroid and other neck structures
Fibrosis in distant sites (retroperitoneum) may be seen. Can be confused with cancer.
Define goiter
A chronic enlargement of the thyroid gland, not due to a neoplasm, occurring endemically in certain locations, especially regions where glaciation occurred and the soil is low in iodine, and sporadically elsewhere.
What is an endemic goiter?
Occurs in areas where the enviorment is low in naturally occurring iodine. Other causative factors lead to incomplete expression. Starts as diffuse enlargement but generally progress to multinodular state
What may a big mutlinodular goiter look like grossly?
encase trachea, focally fibrotic and hemorrhagic suggesting multiple episodes of proliferation, hemorrhage, regression, and fibrosis
What may a colloid nodule look like histologically?
internal regression with cyst formation. Band of fibrosis separates nodules.
