020415 thyroid pathology Flashcards
types of thyroid inflam
infectious thyroidits (TB) subacute granulomatous (de Quervain) thyroiditis chronic lymphocytic (Hashimotos) thyroiditis fibrosing Riedel thyroiditis
what do you see for Hashimoto thyroiditis
diffuse ENLARGEMENT
microscopic:
lymphocytic inflam
germinal centers
Hurthle cell change (epithelial cells with more cytoplasm and more pink due to mitochondria)
subacute thyroiditis (de Quervain)-features?
granulomatous (giant cells)
suppurative (neutrophils)
pain, tenderness
fibrous (Riedel) thyroiditis
due to chronic inflam
painless
microscopic:
dense fibrosis (collagen fibers)
fibrosis can extend outside of thyroid
types of thyroid hyperplasia
Graves’ disease
goiter (diffuse or nodular hyperplasia)–clinical diagnosis
Graves’ disease
autoimmune (diffuse involvement)
microscopic:
irregular follicles (inward folds)
scalloped colloid
histology of goiter
follicles lined by crowded columnar cells
variably sized follicles
abundant colloid
initial–symmetrical, diffuse enlargement
recurrent episodes lead to multinodular gland/goiter
FNA cannot differentiate between
follicular adenoma and follicular carcinoma and hyperplastic nodules
follicular adenoma
benign neoplasm
most are nonfunctional
do not progress to carcinoma
microscopic:
LESS colloid
MORE cells
macroscopic of follicular adenoma
completely surrounded by fibrous capsule (NO capsular or vascular invasion)
prognosis for thyroid carcinoma
mortality is low
risk factor for thyroid carcinoma
ionizing radiation
types of thyroid cancers
papillary CA (most COMMON) follicular CA (like follicular adenomas) medullary CA anaplastic CA lymphomas sarcomas
RET mutation is associated with
medullary carcinoma of thyroid
diagnosis of papillary carcinoma
NUCLEAR FEATURES ARE THE KEY:
clear nuclei-“Orphan Annie eyes”
intranuclear cytoplasmic inclusions
intranuclear grooves
papillary carcinomas look like
papillary architecture (finger like projections)
dense colloid
psamomma bodies (lamellar calcifications)
multinucleated giant cells
vascular spread to bone, lungs, liver
follicular thyroid carcinoma
criteria for diagnosing follicular carcinoma
capsular invasion
vascular invasion
b/c follicular A has no cytologic features of malignancy. most tumors are well-differentiated. cannot differentiate from follicular adenoma unless you see invasion through capsule
medullary carcinoma-what is it
neuroendocrine tumor derived from parafollicular C cells of the thyroid
20% occur within families with MEN 2 syndrome
medullary carcinoma-micro appearance
nests of neuroendocrine cells amyloid stroma (apple green birefringence)
immunohisto for medullary carcinoma
calcitonin, chromogranin, synaptophysin positive
chromogranin and synpatophysin are positive b/c it’s a neuroendocrine tumor
thyroglobulin NEGATIVE
anaplastic carcinoma
undifferentiated tumors of follicular epithelium
most have EXTRATHYROIDAL SPREAD OR DISTANT METASTASIS at presentation (hoarseness due to wiping out laryngeal nerves, neck pain)
