Oatho2 Flashcards
75% to 80% of cases, one of the parathyroid glands harbors a
solitary adenoma
typical parathyroid adenoma
well-circumscribed, soft, tan nodule, invested by a delicate capsule confined to a single gland
The other glands are normal in size or somewhat shrunken, as a result of
feedback inhibition by elevated serum calcium.
Most parathyroid adenomas weigh between
0.5 and 5 g.
LM of parathyroid adenoma
composed predominantly of chief cells
A rim of compressed, non-neoplastic parathyroid tissue, generally separated by a fibrous capsule, often is visible at the edge of the adenoma
The chief cells of the adenoma
larger, show greater nuclear size
variability
Cells with bizarre and
pleomorphic nuclei are often seen
within adenomas = “
endocrine atypia”
…are rare in adenomas
Mitotic figures
contrast with the normal
parathyroid parenchyma, adipose
tissue is
inconspicuous within
adenomas
PARATHYROID HYPERPLASIA typically a
multiglandular process
some cases, however, enlargement may be grossly apparent in only one or
two glands, complicating the distinction between
hyperplasia and adenoma
LM PARATHYROID HYPERPLASIA
the most common pattern → chief cell hyperplasia→ involve the glands in
a diffuse or multinodular pattern
constituent cells in parathyroid hyperplasia contain
abundant clear cytoplasm as a consequence
of the accumulation of glycogen =
water-clear cell hyperplasia
.. inconspicuous within foci of
hyperplasia
stromal fat
PARATHYROID CARCINOMAS enlarge… and • consist of … that sometimes exceed .. in weight
one parathyroid gland
gray-white, irregular masses
10 g
LM of carcinoma
cells usually are
They are arrayed in … patterns
The tumor mass is usually
enclosed by a …
uniform and resemble normal parathyroid cells
nodular or trabecular
dense, fibrous capsule
diagnosis of carcinoma based on …l is unreliable
cytologic detai
only definitive criteria of carcinoma
invasion of surrounding tissues and metastasis
Local recurrence of carcinoma occurs in .. of cases,
more distant dissemination occurs in
one third
another one-third
Morphologic changes in other organs caused by primary hyperthyroidism : • Skeletal changes
increased osteoclastic activity → erosion of bone matrix and mobilization of calcium salts, particularly in the long tubular bones
Bone resorption is accompanied by increased osteoblastic activity →
the formation of new bone trabeculae
more severe cases cortex is ..
Bone marrow..
grossly thinned
contains increased amounts of fibrous tissue
foci of hemorrhage and cysts =osteitis fibrosa cystica
masses
that may be mistaken for neoplasms
brown tumors of hyperparathyroidism
brown tumors of hyperparathyroidism
Aggregates of osteoclasts,
reactive giant cells, and
hemorrhagic debris occasionally form masses
