Pathology Flashcards
C cells
aka: parafollicular cells
secrete CALCITONIN
located in interstitium
IHC STAIN
cretinism
hypothyroidism that develops in infancy or early childhood
Sx: severe mental retardation, short stature, coarse facial features, protruding tongue, umbilical hernia
RARE (iodine is supplemented in food)
hypothyroidism in older children and adults
aka: myxedema
Sx: apathy and mental sluggishness (mimics DEPRESSION), constipation, pericardial effusions, cold intolerant, overweight
mucopolysaccharide rich edematous fluid build up: broad coarse facial features, large tongue, deep voice
Dx: TSH ELEVATED
thyroiditis
give examples
inflammation of the thyroid gland
- Hashimoto thyroiditis
- granulomatous (de Quervain) thyroiditis
- subacute lymphocytic thyroiditis
Hashimoto thyroiditis
women, 45-65 yrs
HYPOTHYROIDISM: MOST COMMON (can be hyperthyroid due to early attack and follicle rupture)
PAINLESS enlargement, followed by ATROPHY yrs later
autoimmune: depletion of thyroid epithelial cells with replacement by inflammation and fibrosis
associations: cytotoxic T cell, HLA-DR3/5
Ab: THYROID PEROXIDASE (TPO), THYROGLOBULIN
risk: B cell lymphoma
subacute granulomatous (de Quervain) thyroiditis
women, 40-60s
uncommon
after FLU-like symptoms: viral induced activation of cytotoxic T cells
PAIN
GRANULOMA (macrophages); giant cells
SELF-LIMITED: most patients fully recover in 6-8 weeks
small number remain hypothyroid permanently
chronic lymphocytic thyroiditis
Hashimotos
subacute lymphocytic thyroiditis
aka: painless or silent thyroiditis middle age women variant of Hashimoto's mild goiter, HYPERTHYROID most don't progress to chronic (hypothyroid) Ab: ANTI-THYROID PEROXIDASE (anti-TPO) NO pain excludes: women within one year after delivery, abortion, miscarriage
Riedel thyroiditis
rare
extensive FIBROSIS (possibly associated with fibrosis elsewhere in body)
WOODY
Graves disease
primary
HYPERTHYROIDISM: MOST COMMON
HLA-DR3
Ab: thyroid stimulating immunoglobulin and thyroid growth stimulating immunoglobulin to TSH RECEPTORS
Sx: diffusely enlarged thyroid, pretibial myxedema, infiltrative opthalmopathy
PAPILLARY infoldings
lab: decrease TSH, free T3/4 increased
infiltrative opthalmopathy
GRAVES
inflammation of soft tissue and muscles around eyes
causes EXOPHTHALMOS (protrusion of eyes)
inflammatory cells, accumulated ECM components, fatty infiltration
pretibial myxedema
GRAVES
aka: infiltrative dermatopathy
thickening skin over shins
due to glycosaminoglycans and lymphocytes
goiter
enlargement of thyroid: MOST COMMON impaired synthesis of thyroid hormone IODINE DEFICIENCY FOLLICULAR hypertrophy and hyperplasia due to increased TSH lab: increase TSH
endemic goiter
geographic
occurs in areas where the environment is low in naturally occurring iodine (greater 10% of populations)
starts diffuse, progresses to multinodular
sporadic goiter
rare
females with increased physiologic demand for T4
goitregens
ingestion of substances that interfere with thyroid hormone synthesis
Brassicaceae (Cruciferae) family: cabbage, cauliflower, brussel sprouts, turnips
What factors increase the chance that a nodule is a neoplasm?
- solitary
- young patient
- male patient
- radiation Hx
NOT hot nodules
hot nodules
take up radioactive iodine
more likely to be BENIGN
thyroid adenoma
aka: FOLLICULAR adenoma MOST COMMON: BENIGN thyroid tumor solitary, encapsulated does NOT breach capsule most non-functional not considered forerunner for carcinoma but has shared genetic alterations
Hurthle cell adenoma
follicular adenoma with lots of Hurthle cells
pathogenesis of toxic adenoma and toxic multi nodular goiter
somatic mutation of TSH receptor signaling pathway: TSHR, GNAS
HYPERTHYROIDISM; functional HOT node
papillary carcinoma
most often: 25-50 years MOST COMMON: MALIGNANT thyroid tumor prognosis: excellent PSAMMOMA bodies, ORPHAN ANNIE metastasis: lymph association: previous ionizing radiation Dx: nuclear features
follicular carcinoma
women, older
more frequent in areas with iodine deficiencies
BREACH CAPSULE, cold imaging
Sx: slow enlarging painless nodule
metastasis: HEMATOGENOUS
prognosis: good, depends on invasion/stage
anaplastic carcinoma
older undifferentiated, follicular epithelium RAPID AGGRESSIVE: mortality near 100% often have Hx of well-differentiated thyroid CA
medullary carcinoma
40-50s yrs for sporadic and familial not associated with MEN2A/2B
C cells/ PARAFOLLICULAR cells
secrete CALCITONIN
most sporadic, rest: MEN2A/2B or FMTC (familial medullary thyroid carcinoma)
activating point mutation in RET proto-oncogenes
AMYLOID
tall cell variant of papillary carcinoma
tall cells with papillary nuclear features
AGGRESSIVE
MEN2B
medullary carcinoma
RET
proto-oncogene
familial and sporadic medullary carcinoma
MEN2A/2B
thyroglossal duct cyst
at birth or in childhood ectopic thyroid MIDLINE: btwn isthmus of thyroid and hyoid bone Sx: repeated infections NOT hormonally active
struma ovarii
mono dermal ovarian teratoma composed mostly of ectopic thyroid
can cause thyrotoxicosis
adenomas are common; 5% malignant
primary hyperparathyroid
more common than hypothyroid
HYPERCALCEMIA
primary: most are adenomas
parathyroid carcinoma is rare
parathyroid adenoma
MOST COMMON: HYPERPARATHYROIDISM HYPERCALCEMIA elevated PTH Sx: depression, muscle weakness, fatigue, renal stones histo: NO fat MOANS, BONES, STONES
hypoparathyroidism
most often caused by accidental removal of parathyroids during surgery
Causes of primary hyperthyroidism
- diffuse hyperplasia (Graves)
- hyper-functioning (toxic) multinodular goiter
- hyper-functioning (toxic) adenoma
- iodine-induced
- neonatal thyrotoxicosis associated with maternal Graves
Cause of secondary hyperthyroidism
TSH secreting pituitary adenoma
RARE
Thyroid diseases not associated with hyperthyroidism
- Granulomatous (de Quervain) thyroiditis
- subacute lymphocytic thyroiditis
- Struma ovarii
- Factitious thyrotoxicosis