Endocrine Pathology

Front 1

How do pituitiary cysts form?

Back 1

Develop from either:
Remnants of craniopharyngeal duct OR cystic dilation of the pituitary cleft.

Front 2

What is the pathogenesis of Pituitary Juvenile (panhypopituitarism) Dwarfism?

Back 2

Failure differentation cell of oropharyngeal ectoderm of Rathke's pouch to hormone-secreting cells of pars distalis --> cyst formation --> compression of other portions of pituitary --> panhypopituitarism

Front 3

What breed does this most commonly affect? What are the gross lesions?

Back 3

German Shepard Dog

Small in size, coyote appearnce to head --> long ears

Front 4

What is the cause of suppurative inflammation in the pituitary gland.

Back 4

Hematogenous spread of ruputred hepatic abscesses in cattle.

Front 5

Describe the lesion associated with non-suppurative (lymphocytic) inflammation of the pituitary gland.

Back 5

Extension of encephalitis into the neurohypophysis. Infiltration of lymphocytes and plasma cells.

Front 6

What is the common neoplastic disease of the pituitary gland?

Back 6

Corticotroph adenoma that may involve the pars intermedia or pars distalis in horses and dogs AND adenoma of the pars intermedia

Front 7

What lesions are associated with corticotroph adenomas?

Back 7

Pituitary mass and bilateral adrenal cortical hyperplasia.

Front 8

What lesions are associated with adenoma of the pars intermedia in horses?

Back 8

Usually large lesion that produces clinical syndrome of hirsutism, polyuria, polydypisa

Front 9

What lesions are associated with adenoma of the pars intermedia in dogs?

Back 9

Usually small and may be functionally inactive or produce Cushing's disease, diabetes insipidus or hypopituitarism.

Front 10

What is diabetes inspidius?

Back 10

Syndrome of polyuria and polydypsia from either lack of adequate ADH (hypophyseal form) or lack of renal response to hormone (nephrogenic form)

Front 11

What lesions are assoicated with diabetes insipidus?

Back 11

Pituitary neoplasms
Pituitary cysts
Post-traumatic hemorrhage

Front 12

List two congential anomalies of the adrenal gland.

Back 12

Accessory cortical nodules: extracapsular masses of cortical tissue that may become prominent with hyperplasia and mistaken for neoplasia.

Hypoplasia: seen with congenital pituitary aplasia.

Front 13

What are 3 causes of adrenal cortical atrophy?

Back 13

Hypopituitarism (lack of ACTH)
Exogenous corticosteroids (feed-back suppression)
Idiopathic in dogs (possibly immune-mediated)

Front 14

What are the lesions of adrenal cortical atrophy?

Back 14

Thin shell of cortex
Decreased size and weight

Front 15

What are the causes of adrenal cortical hyperplasia?

Back 15

ACTH-producing pitutiary chromophobe adenoma

Idiopathic hyperplasia (esp. poodles)

Front 16

Describe the lesions of adrenal cortical hyperplasia.

Back 16

Thick, yellow cortex
May be nodular
Increased size and weight
Proliferation of zona fasciculata

Front 17

What are causes of adrenal cortical necrosis in dogs?

Back 17

Idiopathic

Adrenocorticolytic drugs --> selectively toxic for zona fasiculata and reticularis

Front 18

What are the lesions of adrenal cortical necrosis in the dog?

Back 18

Cortical necrosis, fibrosis and atrophy if chronic.

May produce Addison's Disease

Front 19

List the causes of congestion and hemorrhage in the adrenal gland.

Back 19

Septicemia/Endotoxins
Shock
Stress

Front 20

What can cause infarction of the adrenal glands?

Back 20

Endothelial damage --> thrombosis caused by septicemia (Salmonellosis in horses) and toxemia (volvulus in horses)

Front 21

Where are lesions of infarction localized in the adrenal gland?

Back 21

Red wedge shaped lesion located in the cortex.

Front 22

List and describe the three neoplasms found in the adrenal gland.

Back 22

Cortical Adenoma: dogs and ferrets, encapsulated, expansive growth

Cortical Adenocarcinoma: Dog, ferret, cattle, occassionally functional (Cushings-like), invasive (Posterior VC, Aorta), metastasizes to liver and lung

Pheochromocytoma: Dog and bulls with C-cell tumors, slow growing, invasive and usually non-functional. Can metastisize to lung and liver

Front 23

List two congenital anomolies of the thyroid gland.

Back 23

Cysts (colloid filled)

Accessory glands (found anywhere between tongue and heart)

Front 24

What are the 3 causes of thyroid atrophy?

Back 24

Hypopituitarism

Idiopathic

Aging

Front 25

Describe the lesion of thyroid atrophy?

Back 25

Decreased size and weight, small amount of pale eosinophilic colloid, thin acinar epithilum, replacement by adipose tissue

Front 26

List the three causes of thyroid hyperplasia.

Back 26

Iodine deficiency
Idiopathic
Deficient synthesis of hormone (consumption of goitrogens/genetic enzyme deficiency/Excess iodine)

Front 27

Describe the pathogenesis of diffuse hyperplastic goiter.

Back 27

Blocked or decreaed thryoxine --> excess TTH (TSH) production --> increased number of follicle cell pseudopodia and cells --> hyperplasia of follicle cells

Front 28

Describe the gross and histologic lesions of diffuse hyperplastic goiter.

Back 28

Gross: bilaterally enlarged, dark red, firm

Histo: tall follicle cells, little colloid, "resorption vacuoles" in colloid

Front 29

Describe the pathogenesis of colloid "involutionary" goiter.

Back 29

Deficiency of thryroid hormone --> increased TTH (TSH) --> follicle cell hyperplasia --> increased colloid and thyroid hormone --> decreased pitutiary TTH (TSH) --> decreased endocytosis of colloid by follicular cells with continued colloid synthesis and excess colloid accumulation --> BIG follicles

Front 30

What are the gross and histologic lesions of colloid goiter?

Back 30

Gross: bilaterally enlarged, translucent on section, light color

Histo: flattened follicular cells, abundant colloid, BIG follicles

Front 31

What is the cause of lymphocytic thyroiditis in dogs?

Back 31

Immune-mediated --> important cause of hypothyroidism

Front 32

What are the lesions associated with lymphocytic thyroiditis in dogs?

Back 32

Gross: pale, enlarged or atrophic

Histo: Extensive infiltrates of lymphocytes, plasma cells and macrophages --> replacement fibrosis eventually

Front 33

List and describe the two most common neoplastic diseases of the thyroid gland.

Back 33

Thyroid Adenoma: (1/3 of thryoid tumors) in dogs and horses --> well circumscribed mass, may cause hyperthyroidism in aged cats along with carcinoma or multinodular hyperplasia

Adenocarcinoma: (2/3 of cases) in dogs and horse --> extensive vascular invasion, only rarely functional

Front 34

What clinical expressions of disease are assoicated with hyperparathyroidism?

Back 34

Fibrous osteodystrophy

Hypercalcemia

Front 35

What are the clinical expression of disease with hypoparathyroidism?

Back 35

Hypocalcemic tetany

Front 36

What are the causes of parathyroid hyperplasia?

Back 36

Primary idiopathic: functional parathyroid adenoma

Secondary to chronic renal disease (deficiency of renal 1-alpha-hydroxalase --> deficiency of Vitamin D3) OR (phosphate retention --> hyperphosphotemia --> decreased blood calcium levels)

Secondary to feeding high-phosphorus:low-calcium diets

Secondary to vitamin D deficiency

Tertiary to anal sac carcinoma or lymphosarcoma

Front 37

What lesions are associated with hyperparathyroidsim?

Back 37

Increased size and weight of glands, fibrous osteodystrophy in skeleton and soft tissue mineralization (metastatic)

Front 38

What is the sequelae of hyperparathyroidism?

Back 38

Fractures

Metastatic mineralization

Front 39

What is the common neoplastic disease of the parathyroid gland?

Back 39

Parathyroid adenoma --> encapsulated mass that may be functional (hyperparathyroidism)

Front 40

What are the causes of diabetes mellitus?

Back 40

Idiopathic (dog, vacoulated islet cell)

Chemical Toxin (Alloxan, STH)

Chronic pancreatitis/pancreatic necrosis (dog)

Front 41

What are the pancreatic lesions assoicated with diabetes mellitus?

Back 41

Islet cell necrosis, amyloid deposits in islets, hyaline change in islets, chronic inflammation, atrophy and fibrosis of pancreas, ductal epithelium vacuolation from glygogen accumulation

Front 42

What are extrapancreatic lesions assoicated with diabetes mellitus?

Back 42

Fatty change in the liver and kidneys, glycogen accumulation in the liver and kidneys, cataracts, microangiopathy (kidney and retina)

Front 43

What is the pathogenesis of diabetes mellitus?

Back 43

Decreased insulin production --> glucose unable to enter some tissue --> hyperglycemia --> mobilization of fats for energy --> ketosis, acidosis --> coma

Front 44

What is the pathogeneisis for diatebetes cataract formation?

Back 44

Lens uses glucose via Kreb's cycle --> excess glucose --> shunts to sorbitol synthesis --> excess sorbitol increases lens osmotic pressure --> increased uptake of water --> hydropic degeneration and rupture of lens fibers --> cataract

Front 45

What is the most common neoplastic disease of the endocrine pancreas?

Back 45

Islet cell tumor "insulinoma" --> single or multiple gray firm masses that may be functional and produce hyperinsulinism and hypoglycemia (insulin shock)