Thyroid Pathology (Handorf)--non-neoplastic Flashcards
defn of gland
collection of cells specialized to secrete materials NOT related to their ordinary/intrinsic metabolic needs
secrete substances that act on nearby cells
paracrine
made in cell then secreted into blood where they travel to site of action
endocrine
secrete substances that act on itself
autocrine
pathway that thyroid gland descends during organogenesis
thyroglossal duct
site or origin of thryglosal duct between the floor of bronchial arches 1 and 2
foramen caecum
retrosternal thyroid
developing thyroid moves too far down the mediastinum during organogenesis
Where do lingual thyroids form?
foramen cecum of tongue
problems assc with lingual thyroid?
treatment of lingual thyroid?
difficulty swallowing and breathing (if large enough)
if you remove it, pt no loner has thyroid gland –> hypothyroid and must receive TH replacement therapy
midline nodule vs lateral nodule around the region of the thyroid
midline = thryglossal duct cyst
**in kids usually
lateral = aberrant thyroid (in adults, this is metastatic follicular thyroid carcinoma)
why does a thyroglossal duct cyst need to be removed?
recurrent infections!! also if big enough can obstruct the airway (and for cosmetic reasons)
is a thyroglossal duct cyst considered an ectopic thyroid?
yes, but it usually is NOT hormonally active
term for ectopic thyroid in anterior mediastinum seen with cervical goiter
substernal goiter
*handorf says these develop post-goiter removal/thyroid surgery when some of the thyroid is left behind –> it grows to function as thyroid that was removed?
are substernal goiters symptomatic?
sometimes (trouble swallowing, breathing if be enough) hyper or hypo-thyroid
lateral aberrant thyroid in adult is most likely…
metastatic follicular thyroid carcinoma
Similar location to thyroglossal duct cyst
Often hypothyroid (absent cervical thyroid)
-may be the only thyroid tissue a person has (like lingual thyroid)
suprohyoid/infrahyoid thyroid
Ectopic thyroid tissue in heart
- if this usually function?
- what part of the heart is it usually found?
struma cordis
functional
right ventricle
monodermal teratoma of ovary
struma ovarii
stuma ovarii are composed of mainly ____ tissue
thyroid
presentation of stuma ovarii
woman with over thyrotoxicosis with a whole/absent thyroid (the normal thyroid goes dormant bc the ectopic one is going cray cray)
5 pathologies causing hyperthyroidism. Which one is most common?
- diffuse hyperplasia assc with Graves dz *** 85% of hyperhthyroidism
- early stages thyroiditis
- exogenous thyroid hormone admin
- hyperfunctional mulinodular goiter
- hyperfunctional thyroid adenoma
very thin, non-pitting edema, exopthalmos
Graves dz
pathogenesis of exopthalmos in graves dz
overstim of levator palpebrae superioris + accumulation of loose CT/GAGs behind eyes –> eyes bulge out
pathophys of graves dz
Abs against TSH receptor bind to it and causes thyroid stimulation WITHOUT negative feedback
-these Abs also bind to other tissue sites and inc CT production of GAGs –> exopthalmos and non-pitting edema
histopath buzzwords for graves dz
scalloped colloid and heaped up folds of papillary or hyperplastic epithelium
6 pathologies causing hypothyroidism
impaired TH synthesis: iodine def or lithium
failed thyroid development (cretinism)
surgical removal or thyroid
radiation
suprathyroid lesions (aka in pit or hypothalamus)
thyroiditis
commonest cause of hypothyroidism in N america (aka where we don’t have iodine def)
hashimoto thyroiditis
etiology/pathogenesis of hashimoto thyroiditis
insult –> thyroid Ags recognized by T cells (+ lack of tolerance) –> activate T and B cells –>
Ab mediated damage to thyrocytes –> apoptosis
cytokines and radicals damage thyrocytes –> apoptosis
T cell cytotoxicity kill thyrocytes
=AUTOIMMUNE
(therefore Female > male)
histo progression of hashimoto thyroiditis
lymphocytic infiltrate –> tissue destruction –> fibrosis
diff between early and late hashimoto thyroidits
early = hyperthyroidism (inc follicles)
late = hypothyroidism (destruction and fibrosis)
self limited, post-viral inflammatory process involving thyroid
subacute (granulomatous) thyroiditis
T or F: subacute (granulomatous) thyroiditis is an autoimmune process
F, bc it is self-limiting
but has female predominance
fibrosis of thyroid and other neck structures (might even have fibrosis in retroperitoneum)
Riedel Thyroiditis
why is the thyroid susceptible to infection?
highly vascularized
infection of thyroid + granulomas
milliary TB
infection of thyroid + intralcellular inculsions
CMV
mixed infalmmatory reaction with prominent multi nucleated giant cells
subacute (granulomatous) thyroiditis
chronic enlargement of thyroid gland, not due to a neoplasm
goiter
in what regions are goiters common
where glaciation has occurred (mountainous areas)
=low iodine in soil
endemic goiters start as ______ but progress too ______
diffuse enlargement –> multinodular state (with episodes or regression and enlargement)
Why do goiters get so big???
Hypertrophy is the compensation for the thyroid not being able to make enough T3/4, outgrows their blood supply –> necrosis and fibrosis –> grow more bc T3/4 is still low –> cycle repeats
internal regression and cyst formation + bands of fibrosis separating these lesions
“colloid nodules”
-describing histopath, seen in diffuse and multinodular goiters
