Parathyroid and Adrenal Pathology- Hunt Flashcards
What are some potential developmental abnormalities of the parathyroid glands?
- Ectopic glands
- In thymus
- Anterior mediastinum
- Carotid sheath
- 10% of people have only 2-3 glands instead of 4
How does a parathyroid gland appear grossly?
How much does one weigh?
A yellow-brown ovoid nodule
30-45mg
The parathyroid gland parenchyma is made up of what two cell types?
Which cell types secretes PTH?
What other tissue type has a noticeable presence?
- Parenchyma:
- Mostly Chief cells (secrete PTH)
- Some oxyphil cells
- Large amount of stromal fat
- 30-70%
Name three causes of primary hyperparathyroidism (increased PTH secretion) and their relative occurance rates.
- Hyperplasia (10-15%)
- Adenoma (75-80%)
- Carcinoma (<5%)
Name four general causes of parathyroid hypofunction (decreased PTH secretion).
- Congenital (DiGeorge)
- Iatrogenic (surgery)
- Familial (genetic)
- Autoimmune
- How common is primary hyperparathyroidism in general?
- Is there a sex predisposition?
- What age group it is typically seen in?
- 25:100,000 [aka 1:4000?]
- F:M = 3:1
- Middle age to older adults
List three types of bone disease that can occur secondary to hyperparathyroidism.
- Osteitis fibrosa cystica
- Brown tumor
- Osteoporosis
- What is the pathogenesis of osteitis fibrosa cystica?
- How does the bone appear histologically?
- Erosion of bone matrix by osteoclasts secondary to high PTH
- Bone morphology:
- Grossly thinned cortex
-
Fibrosis of marrow
- Hemorrhage
- Cyst formation
- What is the pathogenesis of a Brown tumor?
- Is it benign or malignant?
- How does the bone appear histologically?
- Excessive osteoclast activity
- Benign lesion - cab be mistaken for a bone neoplasm
- Appearance:
- Osteoclasts & reactive giant cells
- Hemorrhage
- Morphologically identical to giant cell tumor of bone
- How many of the parathyroid glands does parathyroid adenoma typically affect?
- How will the other glands appear?
- Typically, how large (mass) is a parathyroid adenoma?
- Just one
- Normal or atrophic (negative feedback)
- 0.5-5.0g
How does a parathyroid adenoma appear histologically?
- Sheets of chief cells
- Decreased stromal fat
- Oxyphils may be present
- May show a rim of normal paraythyroid at the periphery
How many glands are affected in parathyroid hyperplasia?
- Classically, all four
- May be relative sparing of one or two glands
(contrast with adenoma)
How does parathyroid hyperplasia appear histologically?
- Chief cell hyperplasia and fat cell loss just as in adenomas
- Difficult to distinguish from adenoma histologically
- Key difference: Hyperplasia will lack the rim of normal tissue that adenomas typically (but not always) feature
- How common is parathyroid carcinoma?
- How does it appear histologically?
- Very rare
- Appearance:
- Mitotic activity
- (Sometimes thick) Fibrous bands
- Capsular / vascular invasion
- Cellular atypia alone is not a relaible marker
- At what stage is parathyroid cancer typically first diagnosed?
- What implications does this have for treatment?
- Usually not until already invasive / metastatic
- Difficult to remove from surrounding tissue during surgery
- fibrous adhesions
- How is parathyroid carcinoma diagnosed, as opposed to an adenoma?
- What physical exam finding may increase your suspicion of carcinoma over an adenoma?
- By demonstrating invasion into surrounding tissues or metastasis (which an adenoma would not have)
- Carcinomas are typically firm lesions whereas adenomas are soft
What are the three zones of the adrenal cortex?
What is produced in each zone?
Zona Glomerulosa- aldosterone
Zona Fasciculata- glucocorticoids
Zona Reticularis- Sex hormones
“It gets sweeter as you go deeper”
What cells are found in the adrenal medulla?
What is produced in the medulla?
Chromaffin cells
catecholamines (epinephrine)
What three over-producing pathologies can affect the adrenal cortex?
What over-producing pathology can affect the adrenal medulla?
Cortex
- Adrenocortical hyperplasia
- Adrenocortical adenoma
- Adrenocortical carcinoma
Medulla
- Pheochromocytoma
What area of the adrenal gland typically enlarges in adrenocortical hyperplasia?
What cells are mostly affected?
Zona fasciculata
Clear cells
What area of the adrenal glands does adrenocortical adenoma affect?
What does the adenoma look like grossly?
Zona Fasciculata
Yellow, encapsulated
THESE ARE TYPICALLY NON-FUNCTIONAL
Adrenocortical carcinoma or adenoma?
Large?
Well-differentiated?
Necrosis?
Pleimorphic?
Common?
Large- carcinoma
Well-differentiated- either
Necrosis-carcinoma
Pleimorphic-carcinoma
Common-adenoma
Patient present with hypercortisolism. What is the cause if the adrenals show:
atrophy?
bilateral enlargement?
a unilateral mass?
atrophy- exogenous glucocorticoids
bilateral enlargement- increased ACTH (pituitary adenoma)
unilateral mass- adrenocortical adenoma/carcinoma
Patient presents with hyperaldosteronism. What are they mostly to have?
What is the name for this disease?
adrenal cortical adenoma
Conn Syndrome
What is congenital adrenal hyperplasia?
What adrenal pathologies are seen?
Any recessive mutation that blocks steroidogenesis from the adrenal glands
bilateral hyperplasia
What does a pheochromocytoma look like histologically?
What markers could identify this as a pheochromocytoma?
Zellballen (cells nests)
granular, basophilic cytoplasm
stain for chromogranin or synaptophysin (neuroendocrine markers)
What is a paraganglioma?
Where are they most likely to be found?
Extra-adrenal pheochromocytoma
jugulotympanic, carotid body, vagal, aorticopulmonary
What is the rule of tens for pheochromocytomas?
- 10% are malignant
- 10% are bilateral
- 10% are extra-adrenal
- 10% are pediatric
