157 Thyroid histo/path Flashcards
Thyroid
-embryological origin?
1st pharyngeal arch
endodermal origin
what connects thyroid to the base of the tongue?
thryoglossal duct - should obliterate during gestation –> if not, pathology as adult
do thyroid nodules move with deglutition?
yes
Thyroid - histo
capsule penetrates and divides into lobules
20-40 follicles per lobules
what surrounds colloid?
simple follicular epithleium
what do C-cells secrete? what cancer do they cause?
calcitonin
medullary carcinoma
how are thyroid nodules evaluated?
FNA
what causes a midline mass superior to the isthmus? histo? treatment?
thyroglossal duct cyst - failure of atrophy
cyst w/ squamous epi filled with proteinaceous fluid
surgery requires removal of hyoid bone (cosmetic surgery)
Chronic lymphocytic (Hashimoto) thyroiditis -cause?
autoimmune abs –> TG and TPO
Chronic lymphocytic (Hashimoto) thyroiditis -macro appearance?
diffusely enlarged gland
Chronic lymphocytic (Hashimoto) thyroiditis -micro appearance?
inflammatory cells with germinal cells
follicles atrophy with Hurthle cells (follicular epi cell regenerate with metaplasia) –> big pink cells with lots of mitochondria
Chronic lymphocytic (Hashimoto) thyroiditis -risk?
other autoimmune disease
b-cell non-hodgkin lymphomas
Graves’ Disease - cause
autoimmune Abs against TSH receptor –> activating (hyperthyroidism)
Graves’ Disease - presentation
hyperplasia of gland - diffuse enlargement
ophthalmopathy - eyes are large
dermatopathy - skin changes
Graves’ Disease - treamtent
1st - radioactive
if fail - surgery
Graves disease - micro histo
papillary hyperplasia with tall follicular cells
lack nuclear features of papillary carcinoma
Adenomatous/Colloid/ Hyperplastic Nodule
benign hyperplastic nodule/goiter
Adenomatous/Colloid/ Hyperplastic Nodule - single or multiple
usually multiple
Adenomatous/Colloid/ Hyperplastic Nodule - histo
hyperplastic –> outgrow vasculature –> necrosis and hemorrhage –> dystrophic calcification –> involution
repeat cycles of hyperplasia and involtion –> nodules
Thyroid Neoplasms
adenomas = benign carcinoma = malignant
Follicular/Hurthle Cell Adenoma - mutiple or single nodules?
usually single from follicular epithelium
can’t distinguish from follicular carcinomas until excised
Follicular/Hurthle Cell Adenoma
intact capsule surrounding small follicles (rosettes) - carcinomas break through capsule and vasculature
(other nodules don’t have a capsule)
monoclonial (nodules are often polyclonial)
Follicular/Hurthle Cell Carcinoma
capsular invasion
vascular invasion
RAS and PAX8 mutations are common
most common thyroid carcinoma? cause? mutations? spread?
papillary carcinoma
radiation
MAP kinase pathway
RET
BRAF activating point mutation
lymph - can be mulitfocal so must take out entire gland with surgey
