Literally just Austins Quizlet in a different browser

Which lesion is more likely to be bilateral, adenoma or carcinoma?

Carcinoma

Hyperplasia of the whole organ due to increased workload is described as what?

Physiologic hyperplasia

Which lesion is more likely to be well demarcated and encapsulated, adenoma or carcinoma?

Adenoma

What does it mean if a tumor is functional?

It secretes excess hormones

Where are pituitary cysts derived from?

Craniopharyngeal duct

The failure of oropharyngeal ectoderm to develop into hormone secreting cells is called what?

Cystic Rathke's pouch

What are the major signs of cystic Rathke's pouch

Stunted growth and retained puppy coat (esp. in Germans)

Cystic Rathke's pouch is from a DNA mutation in what gene?

LHX3

What tumor can cause central blindness, muscle atrophy, intra-abdominal fat deposits, and, if functional, secretes ACTH in the dog?

Adenoma of pars distalis

An adenoma of pars distalis will cause hypertrophy of what organ?

Adrenal cortex

What integument signs occur with adenoma of pars distalis in dogs?

Flank alopecia and calcinosis cutis (mineralization)

Adenoma of pars intermedia is more common in what species?

Horses

Adenoma of pars intermedia secretes what hormone?

POMC

Adenoma of pars distalis produces what hormone in cats?

Growth hormone

What two disorders result from excess growth hormone?

Acromegaly (gangster jaw) and diabetes mellitus

What behavior in deer and sheep can predispose to pituitary abscesses?

Head-butting

A normal adrenal gland will have what ratio of the width of cortex to medulla?

1:1:1

What are the three layers of the adrenal gland's cortex from superficial to deep, and the things they produce?

Glomerulosa: mineralocorticoids, Fasciculata: glucocorticoids, Reticularis: sex hormones

T/F: Nodular cortical hyperplasia is a common cause of adrenal disease due to increased hormones

False, often incidental finding and non-functional

A cortical adenoma of the adrenal gland will secrete what if functional?

Cortisol

Disease of the adrenal cortex will lead to what electrolyte imbalance in cats?

Hypokalemia

What are some key signs of hypokalemia in cats?

Plantigrade stance, difficulty jumping, and cervical ventroflexion

What disease of the adrenal gland is pink, fleshy, and secretes catecholamines (epinephrine) if functional?

Pheochromocytoma

What major organ will be secondarily affected by pheochromocytoma?

Heart (hypertrophy, hypertension)

What is the most frequently observed lesion in dogs with hypoadrenocorticism?

Bilateral idiopathic adrenal cortical atrophy

What adrenal lesion is seen secondary to septicemia?

Adrenal hemorrhage

Where does the assembly of hormone take place in the thyroid?

In the follicular lumen

Nodular hyperplasia of the thyroid is usually non

functional except in what species?-Cats

What lesion of the thyroid is large, hemorrhagic, and necrotic?

Follicular carcinoma

What pathology is associated with follicular cell carcinomas?

Cannonball pulmonary metastases

What thyroid lesion is common among older bulls on high calcium diets?

C-cell tumors

Lymphocytic thyroiditis is an autoimmune disease with antibodies against what cells?

Thyroglobulin, T3, and T4

Myxedema, tragic facial expressions, and atherosclerosis are all pathology of what disease?

Hypothyroidism

The gross enlargement of the thyroid glands, often from iodine imbalance, is called what?

Goiter

What hormone is released in response to low calcium in order to increase calcium levels?

PTH (Calcium too low? PTH says go!)

What hormone is released in response to high calcium in order to decrease calcium levels?

Calcitonin (Calcium too high? Calcitonin says bye!

How will chronic low levels of calcium affect the parathyroid?

It will cause overstimulation and hyperplasia

What is the primary associated pathology with hyperparathyroidism?

Fibrous osteodystrophy (PTH raises blood calcium by taking from bones)

What disease in dogs can cause pseudohyperparathyroidism by increasing levels of PTHrP?

AGASACA

What cell of origin is most common for pancreatic tumors?

Beta cells (insulinoma)

T/F: Pancreatic islet cell tumors metastasize once they grow larger than 1 cm

False, metastasize when smaller than 1 cm

What pancreatic islet cell tumor leads to GI ulcers and vomiting?

Gastrinomas

What pancreatic islet cell tumor is associated with superficial necrolytic dermatitis due to hypoaminoacidemia?

Glucagonoma

What histologic pattern is present for glucagonoma?

French flag

In type two diabetic cats, pancreatic islets can be replaced by what eosinophilic material?

Amyloid

What histologic characteristic is developed due to long term overstimulation of the pancreas?

Vacuoles

Neuroendocrine system tumors secrete what?

Vasoactive amines and gastrin

Thyroid review: The hypothalamus produces what hormone?

TRH

Thyroid review: TRH acts on what organ?

Pituitary

Thyroid review: The pituitary produces what hormone?

TSH

Thyroid review: TSH acts on what organ?

Thyroid

Thyroid review: The thyroid produces what hormones?

T3 and T4

Thyroid review: T3 negatively affects what organ?

Pituitary

Thyroid review: T4 negatively affects what organ?

Hypothalamus

What is the major active thyroid hormone intracellularly?

T3

What is the major active hormone extracellulalry?

Free T4

What is the main (known) cause of primary hypothyroidism in dogs?

Lymphocytic thyroiditis

If a dog has hypothyroidism due to thyroiditis, what level should TSH be at?

High (to make more T4)

T/F: You should test healthy patients for hypothyroidism on a whim in case they have it

False, only test if there are clinical signs

What are the three most common signs of hypothyroidism?

Non-pruritic alopecia, obesity with decreased appetite, and lethargy

What is the extreme presentation of hypothyroidism?

Myxedema coma

What other than thyroid related causes can decrease thyroid hormone?

Illness (euthyroid sick)

What test is useful to rule out hypothyroidism?

Total T4

Your patient has a low total T4. Does this patient have hypothyroidism?

Not enough info. Can only rule out disease if total T4 is normal

What is the most reliable test for hypothyroidism?

Free T4

Your patient has a low free T4. Does this patient have hypothyroidism?

Most likely, yes

What test is useful to rule in hypothyroidism?

TSH

Your patient has a normal TSH. Does this patient have hypothyroidism?

Not enough info. Can only rule in disease if TSH is high

Why might a patient showing signs of hypothyroidism have a high total T4?

Autoantibodies increase results

If thyroiditis is falsely increasing T4 measurements, how do you obtain a diagnosis for hypothyroidism?

Measure fT4 by dialysis

What values for total T4, free T4, and TSH are definitively hypothyroidism?

Low total T4, low free T4, and high TSH (assuming not non-thyroidal sick)

Your patient is healthy without signs, but has low total T4. What should you do?

Nothing, don't treat if healthy

Your patient is healthy without signs, but has high total T4. What should you do?

Check for autoantibody levels

Your patient has alopecia and hypercholesterolemia, with low total T4, low free T4, and normal TSH. What should you do?

Treat for hypothyroidism! Free T4 is a good indicator of disease.

Your patient has alopecia and mild anemia, with borderline total T4, borderline free T4, and normal TSH. What should you do?

Recheck in 3 months, could be from other diseases and not severe enough to rule in hypothyroidism

What is the goal for test results after a month of treatment of hypothyroidism?

To be in the upper half or slightly higher of the reference range for total T4

What is the main signs associated with congenital hypothyroidism?

Disproportionate dwarfism and goiter

What are the most common signs of hyperthyroidism in cats?

Weight loss, polyphagia, and vomiting

T/F: Palpable goiter is present in most hyperthyroid cats

True (90%)

What test is good at ruling in hyperthyroidism?

Total T4

Does a cat with high total T4 have hyperthyroidism?

Yes!

What test is good at ruling out hyperthyroidism?

Free T4 and TSH

If a cat has a high free T4, does it have hyperthyroidism?

Not enough info. Can only rule out disease if free T4 is normal

A cat has a high total T4. Does he have hyperthyroidism?

Yes

A cat has a lower RR total T4. Does he have hyperthyroidism?

No

A cat has an upper RR total T4. Does he have hyperthyroidism?

Depends on free T4. If free T4 is high, then yes. If free T4 is low, then no.

A cat has a high total TSH. Does he have hyperthyroidism?

Probably not (since should only have a high TSH if T4 is relatively low)

What is the MOA for methimazole?

Inhibits hormone synthesis

What are the most common side effects of methimazole?

Gastrointestinal (anorexia, vomiting, lethargy)

What should you do if your cat gets GI side effects on methimazole?

Stop and lower dose

What should you do if your cat gets excoriation and bleeding side effects on methimazole?

Stop forever!

What is the gold standard therapy of hyperthyroidism?

Radioactive iodine to kill functional cells

What is the max amount of time it takes for radioactive iodine to work?

3 months

T/F: Hyperthyroidism causes kidney disease

False, hyperthyroid cats are older and thus get CKD

T/F: Hyperthyroidism can mask kidney disease

True, increases GFR and decrease azotemia

What is a major clinical marker that helps determine prognosis?

Azotemia (worsens prognosis)

You give a hyperthyroid, azotemic cat methimazole for 30 days, and the azotemia is mildly worse. Can you pursue curative treatment?

Yes, since the azotemia is only mildly worse, you can treat with surgery or radioactive iodine

What is the best way to diagnose hypothyroidism in cats after treatment?

High TSH

If a cat has high TSH, what must next be measured to determine if it is overt or subclinical hypothyroidism?

T4 levels (low = overt, low-normal = subclinical)

How do we determine if a subclinical hypothyroid cat should receive treatment now or six months after iodine treatment?

Azotemia (azotemic = now, not azotemic = wait)