Pituitary Disease and Insulinoma

Question 1

1/3 of middle to old age, uncontrolled diabetic cats have a tumor on the pars distalis that causes an excess of growth hormone. What disease does this cause?

Answer 1

Acromegaly

Question 2

How does an increase in growth hormone affect diabetics?

Answer 2

Further decreases tissue insulin sensitivity

Further decreases glucose transport

Question 3

A 14 year old MN diabetic cat named Georgey presents for recent onset of seizures. You can feel the liver on abdominal palpation and you detect stridor on auscultation of the trachea. Oral exam is as pictured. What diagnostics would you like to do?

Answer 3

CT/MRI of the brain

Insulin-like growth factor-1 level

Ultrasound changes

Question 4

You perform an ultrasound on Georgey and find the adrenals, kidneys, and pancreas to be enlarged. Based on the clinical presentation and ultrasound findings in the abdomen, what do you expect to see when you ultrasound the heart?

Answer 4

Cardiac hypertrophy

Question 5

What 2 clinical findings in acromegaly cats significantly reduce survival time?

Answer 5

Arrhythmias

Hypertension

Question 6

What are the treatment options for Georgey?

Answer 6

Radiotherapy

Surgery

Medical (most common)

Question 7

Medical management of cats with acromegaly involves what drugs?

Answer 7

Insulin - no more than 5U BID

ACE inhibitors - proteinuria (kidney dz)

Diuretics - heart failure

B Blockers - dysrrhythmias

Question 8

Georgey didn’t have hypertension or arrhythmia on exam. What is his MST?

Answer 8

2-3 years

Question 9

You are examining a 5 year old F Labrdor who is being treated with progestagens. Based on her clinical signs you suspect acromegaly, which IGF-1 level confirms. What is the treatment for this dog?

Answer 9

Discontinue progestagens

Spay

Question 10

The anterior pituitary is responsible for synthesizing which 6 hormones?

Answer 10

GH

TSH

PRL

FSH & LH

ACTH

Question 11

A client brings in a German Shepherd puppy they just adopted from a shelter. The paper from the shelter states that the animal is 5 months old, but you estimare him to be at least 2 years old. Deciduous teeth are retained, along with the adult teeth that have grown in. The coat is sparse and consists of only guard hairs, and the skin is dark. Tesicles are not palpable. There is no response to pituitary stimulation test (TRH stimulation) and the T4 is low. What is the diagnosis in this patient?

Answer 11

Pituitary Dwarfism

*Low TSH, GH, FSH, LH

*German Shepherds retain normal ACTH levels

Question 12

You tell the client that with treatment, these animals can live longer than 5 years, and she agrees to try medicating the dog. What medications will you send her home with?

Answer 12

Levothyroxine

Porcine GH

Question 13

A 6 year old dog presents with a history of collapse. BP is 120mmHg [120-150]. You do a spot glucose and the level is extremely low at 15mg/dL. You also measure an insulin level, and the insulin:glucose ratio is 4.5. What is this diagnostic for in this patient?

Answer 13

Insulinoma

*Insulin levels should be low when the BG is that low. Normal or high insulin levels, or an insulin:glucose ratio greater than 4.2 is diagnostic.

Question 14

You perform a CT on the dog with suspected insulinoma. What are you looking for?

Answer 14

Pancreatic mass

*most are located in the left lobe

Question 15

In patients with insulinomas, what is the first line of treatment?

Answer 15

Surgery!

Question 16

What disease can patients develop after surgical resection of an insulinoma?

Answer 16

Diabetes mellitus

Question 17

For insulinoma patients who won’t be having the mass surgically removed, what is the medical treatment?

Answer 17

Prednisone (inhibits insulin, stimulates glycogenolysis)

Diazoxide (inhibits insulin secretion)

OR
Octreotide (inhibits insulin synthesis)

Can try dietary control but it doesn’t go very well