Adrenal Gland Pathology Flashcards
where are the adrenal glands located
retroperitoneal space - cranial and medial to the kidneys
what blood vessel are the adrenals closely associated with
phrenicoabdominal vein
what is the normal cortex to medulla ratio
factor of 3
(1:1:, 1:2, 1:3, 2:1, 3:1)
is the zona glomerulosa distinct on histology
yes
is the zona fasiculata and reticularis distinguishable from each other on histology
no
what zone(s) produce cortisol
zona fasiculata
zona reticularis
what zone(s) produce aldosterone
zona glomerulosa
what is the primary regulator of cortisol
ACTH
what is the primary regulator of aldosterone
ANG II
adrenocortical hemorrhage
blood in the interstitium of the adrenal gland
what species does adrenocortical hemorrhage occur and what are the causes
foals
stress, sepsis, toxemia
can you differentiate between hemorrhage and congestion grossly
no - need histology
adrenalitis
inflammation of the adrenal cortex
what species is adrenalitis common in
dogs
what are the causes of adrenalitis
granulomatous: fungal or parasitic
lymphocytic: immune mediated (affects all 3 layers)
idiopathic adrenocortical atrophy (IAA)
atrophy of all three cortical layers
suspected to be caused by lymphocytic adrenalitis
what endocrinopathy occurs secondary to IAA
hypoadrenocorticism (Addison’s disease)
what lesion is associated with IAA
atrophied cortex
(1:6 to 1:10 cortex:medulla ratio)
what species is IAA common in
dogs
adrenal trophic atrophy
atrophy of the zona fasiculata and reticularis caused by low ACTH production from the pituitary
pathogenesis of trophic atrophy
low ACTH –> under stimulation of fasiculata/reticularis –> low cortisol production
is the zona glomerulosa affected in trophic atrophy
NO - because aldosterone secretion is NOT stimulated by ACTH
what are the causes of trophic atrophy
- pituitary masses - can cause over/under/no change in production of ACTH; if causes underproduction - leads to trophic atrophy
- iatrogenic - chronic administration of exogenous glucocorticoids leads to negative feedback on pituitary –> shuts down ACTH production –> trophic atrophy
adrenal disorders of growth
hyperplasia –> adenoma –> carcinoma
is nodular hyperplasia of the adrenal gland associated with an endocrinopathy
NO
can you differentiate medullary vs cortical adenomas grossly
NO
what is a unique feature of adrenal carcinomas
can recruit hematopoietic cells - will see bone marrow cells present in tumor
hyperadrenocorticism (Cushing’s)
overproduction of cortisol from the adrenal cortex
what species is Cushing’s most common in
dogs
clinical signs of Cushing’s
- PU/PD/PP
- truncal alopecia
- pot-belly
what are the types of Cushing’s disease
- pituitary dependent
- adrenal dependent
- iatrogenic
pituitary dependent cushing’s
most common form
caused by a functional pituitary tumor leading to over secretion of ACTH
what lesion is associated with pituitary dependent Cushing’s
bilateral adrenal hypertrophy
adrenal dependent Cushing’s
less common form
adrenal cortical adenoma/carcinoma leading to over secretion of cortisol
what lesion is associated with adrenal dependent Cushing’s
unilateral adrenal atrophy (of the contralateral adrenal gland)
mass in one adrenal, other one atrophies
iatrogenic Cushing’s
caused by exogenous administration of glucocorticoids
what lesion is associated with iatrogenic Cushing’s
trophic atrophy
atrophy of the zona fasiculata and reticularis
hyperaldosteronism (Conn syndrome)
adenoma or carcinoma of the zona glomerulosa
leads to hyper secretion of aldosterone –> excess water and Na retention –> hypertension
treat w/ loop diuretics
RARE in veterinary species
is neoplastic metastasis to the adrenals common
yes - highly vascularized
what is the most common endocrinopathy of ferrets
adrenal associated endocrinopathy (AAE)
adrenal associated endocrinopathy (AAE)
hyperplasia/adenoma/carcinoma of the adrenals
carcinomas more common than benign
pathogenesis of AAE
early gonadectomy –> loss of GnRH suppression –> overstimulation of LH –> overproduction of sex steroids –> excess estrogen in blood
what are clinical signs of AAE
females: enlarged vulva
symmetrical hair loss
PU/PD
high estrogen in blood
bone marrow suppression
pheochromocytoma
tumor of the adrenal medulla (chromaffin cells)
in what species are pheochromocytomas most common in
dogs, horses, ruminants, ferrets
what is the main clinical sign of pheochromocytomas
episodic hypertension
caused by episodic overproduction of epi/NE –> increases BP
what is dangerous about surgical removal of pheochromocytomas
often cause dangerously high spikes in blood pressure due to massive release of epi/NE during manipulation
