Parathyroid
Hyperplasia
Epidemiology and Etiology:
- Primary:
- Adenoma (75-80%)
- Diffuse or nodular
hyperplasia (10-15%)
- Parathyroid
carcinoma (<5%)
- F:M = 3:1
- secondary:
- chronic renal
insufficiency
- inadequate dietary
intake of calcium
- vitamin D
deficiency
- steatorrhea
- tertiary:
- chronic renal
insufficiency
Common sites:
- metastatic
calcification may be seen in primary or secondary hyperparathyroidism
- lungs
- heart
- stomach
- blood vessels
Gross features:
- frequently
assymetry in glandular involvement
- but usually all
are enlarged to some degree (in contrast to adenoma)
- combined weight of
all glands usually less than 1g
Histologic features:
- chief cell
hyperplasia
- poorly-developed,
delicate fibrous strands may envelop nodules
- inconspicuous fat
within gland (in contrast to normal parathyroid)
- water-clear
hyperplasia:
- constituent cells
with clear cytoplasm
Immunophenotype:
Marker:
|
Sensitivity:
|
Specificity:
|
|
|
|
Molecular features:
- familial:
- MEN-1
- MEN-2A
- Familial
Hypocalciuric Hypercalcemia (FHH)
- CASR mutations
mostly
- mutations
in parathyroid calcium-sensing receptor gene (CASR) on 3q
- homozygous
mutations present neonatally
- Sporadic:
- MEN1 mutations
- Monoclonal often
Other features:
References:
- Robbins &
Cotran Pathologic Basis of Disease (2005)