Pathology of pituitary, parathyroid, adrenal glands Flashcards
pituitary adenomas
10-15% of all intracranial neoplasms, F>M, 3rd to 6th decades,
hormonal secretion: Prolactin is most common (approximately 30%)- lactotrophs, acidophil, Non secreting (null cell) is next (approx 25%), GH ACTH next most common, rarely secrete more than one hormone
Pituitary adenoma is just one color no acidophils
very little reticulin (no lobuleS)
Sheehan syndrome, post partum hypopituitarism
Postpartum ischemic necrosis of pituitary gland, pituitary gland enlarges in pregnancy (increased lactotrophs), more susceptible to ischemia, obstetrical hemorrhage or shock, results in hypopituitarism (anterior Not posterior)
Stalk effect
slight elevation in prolactin level, result of lack of inhibitory hypothalamic influence on prolactin, caused by a mass/destructive lesion pressing on stalk or hypothalamus- not a prolactin secreting adenoma
Rathke cleft cyst
Sella or suprasella location. May produce symptoms or may be asymptomatic found at autopsy
Columnar to cuboidal cells with cilia and occasionally mucin , lining a thin walled cyst, developmental origin (remnant of rathkes cleft pouch)
Cranipharyngioma
Benign tumors, usually suprasellar, may be within sella, third ventricle or pineal region
2 age peaks (kids, and old adults)
Presenting symptoms Visualt abnormalities (chiasm), hypopituitarism
Histogenesis is uncertain, misplaced odontogenic epithelium, vestigal remnants of rathkes pouch
Parathyroid development
Arise from the pharyngeal pouches, (inferior and thymus- 3rd pharyngeal pouch, superior - fourth pharyngeal pouch), Are normally located in proximity of upper and lower poles of the thyroid gland
May be ectopically located in thymus, anterior mediastinum, carotid sheath
10% of people have only 2 or 3 glands instead of the normal 4
yellow brown, composed primarily of chief cells and some oxyphil cells
In adults there is a large amount of interveneing stromal fat (30-70%), chief cells secrete parathyroid hormones
Chief cells are white with blue nucleus
Parathyroid abnormalities
Hyper secretion: Parathyroid hyperplasia, parathyroid adenoma, parathyroid carcinoma
Hypofunction (decreased secretion ofPTH)- Congenital (digeorge syndrome), iatrogenic (surgical), familial, autoimmune
Primary hyperparathyroidism
F>M, middle age, adenoma, Primary hyperplasia and parathyroid carcinoma
Bone disease in hyperparathyroidism
Osteitis fibrosa cystica (erosion of bone matrix by osteoclasts), grossly thinned cortex, fibrosis of marrow with hemorrhage and cyst formation
Brown tumor- osteoclasts, reactive giant cells, hemorrhage, morphologically identicle to giant cell tumor of bone
Parathyroid adenoma
solitary nodule arising in a single parathyroid gland
.5-5 gms
other glands are either normal or atrophic
composed of sheets of chief cells with decrease in stromal fat, oxyphil cells may also be present, may show a rim of normal parathyroid at the periphery
Parathyroid hyperplasia
Classically all four glands are involved, might be sparing of 1 or 2
Morphologically there is chief cell hyperplasia just as in adenomas
May be difficult to distinguish histologically from adenoma
diffuse not normal even on edge
Parathyroid carcinm
Rare, difficult to distinguish from adenomas, usually not dignosed until they become clearly invasive and/or metastatic
Cellular atypia is not a reliable feature of malignancy, mitotic activity, fibrous bands, and capsular/vascular invasion
difficult to remove from surrounding structures at the time of surgery due to fibrous adhesions
Adrenal gland histology
Cortex: zonal glomerulosa (G): mineralocorticoids (aldosterone)- salt. Zona fasciculata (F) glucocorticoids (cortisol- sugar). Zona reticularis (R) sex steroids (estrogens and androgens)- Sex)
MEdulla (M)- Chromaffin cells–> catecholamines (epinephrine)
Adrenocortical hyperplasia
Bilateral thickening of the adrenal cortex (Diffuse, nodular)
Predominantly fasciculata cells- clear cells, microscopically resembles adrenocortical adenoma
Largeer zone of clear cells
adrenocortical adenoma
yellow, encapsulated, 1-2 cm, <30gm, functional or non- functional (Cannot be determined by histology, most are non functional), Predominantly zona fasciculata cells, like hyperplasia, solitary encapsulated lesion
lots of clear cells