Hyperadrenocorticism Flashcards
(46 cards)
1
Q
OBJ: Understand adrenal gland functional anatomy and regulation
A
2
Q
OBJ: Know the common clinical signs of hyperadrenocorticism (HAC)
A
- PU/PD
- normal to increased appetite
- panting, restless, anxiety
- Cushingoid body type
- pendulous distended abdomen
- muscle wasting
- thin coat
- multiple dermatologic lesions
- thin skin
- comedones
3
Q
OBJ: Understand the two most common types of HAC (PDH and ADH)
A
- Pituitary Dependent Hyperadrenocorticism
- Pituitary
- Adenoma
- 85% of cases
- bilateral enlargement of adrenal size due to hyperplasia
- Adrenal Dependent Hyperadrenocorticism
- adrenal gland
- adenoma or adenocarcinoma
- 15% of cases
- Unilateral enlargement
- contralateral atrophy
4
Q
OBJ: Understand common screening and differentiating test for HAC
A
- Screening
- UCCR
- LDDST
- ACTH
- Differentiating
- Adrenal US
- Endogenous ACTH measurement
- HDDST
5
Q
OBJ: Know treatment options for PDH and ADH
A
- PDH
- hypophysectomy
- Medical management
- anti-adrenal therapy
- pituitary therapy
- Radiation
- ADH
*
6
Q
OBJ: Review/Understand Pertinent aspects of feline HAC
A
- PDH
- hypophysectomy
- Medical management
- anti-adrenal therapy
- pituitary therapy
- Radiation
- ADH
- Adrenalectomy
- Anti-adrenal therapy
- Trilostane
- Lysodren
- Ketoconazole
- Anipryl
7
Q
How is cortisol secretion regulated?
A
- Regulated through the Hypothalamic Pituitary Adrenal Axis (HPAA)
- See Image
- ACTH secretion is pulsatile
- Influenced by:
- Feeding
- Physiologic / environmental stress
- Pain
- Trauma
- Hypoxia
- Pyrogens
- Cold exposure
- Surgery
- Influenced by:
8
Q
What is the difference between PDH and ADH?
A
9
Q
What is the common signalment of hyperadrenocorticism in dogs?
A
- Any breed
- Median age of diagnosis is 10-11yr
10
Q
What are the clinical signs of Hyperadrenocorticism?
A
- Dogs with HAC generally feel and act well
- PU/PD - almost all dogs with HAC
- Appetite normal to increased
- Panting, restlessness, anxiety
- ‘Cushingoid’ body type
- pendulous and distended abdomen
- muscle wasting
- thin coat
- multiple dermatologic lesions
- thin skin
- comedones
11
Q
What neurologic signs are common in hyperadrenocorticism dogs?
A
- signs caused by macroadenoma (10-15% PDH cases)
- Anorexia
- behavioral changes
- disorientation
- blindness
12
Q
What Cardiovascular effects are common in hyperadrenocorticism dogs?
A
- Hypertension
- Thromboembolism (hypercoagulable)
13
Q
What musculoskeletal problems are common in hyperadrenocorticism dogs?
A
- Poor body condition
- muscle loss
- cruciate rupture
- myopathy
14
Q
What reproductive signs are common in hyperadrenocorticism dogs?
A
- decrease in testicular androgen production in males
- Anestrus in females
15
Q
What findings are common on diagnostic imaging in dogs with hyperadrenocorticism
A
- Hepatomegaly
- Adrenal tumor
- Focal calcification
- Lung mineralization
16
Q
What CBC findings are common in hyperadrenocorticism dogs?
A
- Anemia is uncommon
- Stress leukogram - neutrophilia, lymphopenia
- Thrombocytosis
17
Q
What Serum Chemistry findings are common in hyperadrenocorticism dogs?
A
- Elevated liver enzymes (ALP > ALT)
- ALP - GC induced isoenzyme
- ALT - vacuolar hepatopathy
- Hypercholesterolemia
- Hyperglycemia (mild)
18
Q
What urinalysis findings are common in hyperadrenocorticism dogs?
A
- Low urine specific gravity <1.020
- Proteinuria
19
Q
How is hyperadrenocorticism diagnosted?
A
- 2 step approach
- Screening tests - confirm adrenal hypersecretion
- Urine cortisol:creatinine ratio (UCCR)
- Low does dexamethasone suppression test (LDDST)
- ACTH stimulation test
- Differentiating tests - distinguish PDH and ADH
- Adrenal US (or other dx imaging)
- endogenous ACTH measurement
- High dose dexamethasone suppression test (HDDST)
- Screening tests - confirm adrenal hypersecretion
20
Q
What do the results of a Urine Cortisol : Creatinine Ratio (UCCR) test mean?
A
- Dogs with HAC have elevated urine cortisol:creatinine ratio
- normal results rule out HAC - high specificity
- Abnormal result require confirmation with another screening test
21
Q
What do the results of a Low Dose Dexamethasone Suppression Test (LDDS) mean?
A
- Effective screening test
- can be a differentiating test
- dogs with HAC have elevated 8-hr cortisol
- Stress / Nonadrenal illness = False +
22
Q
What do the results of a ACTH stimulation Test mean?
A
- Generally considered more Specific than LDDS
- Dogs with HAC have elevated post-ACTH cortisol
- Cannot distinguish between PDH and AT
23
Q
What Hyperadrenocorticism screening test is a good choice if non-adrenal illness is suspected?
A
ACTH Stimulation test
24
Q
What do the results of a High Dose Dexamethasone Suppression Test (HDDST) mean?
A
- Suppression = PDH
- 70% of PDH cases suppress - can differentiate from AT
- 30% of PDH cases do not suppress
- No Suppression = AT
25
What doe the results of an Endogenous ACTH Test (eACTH) mean?
* Low = AT
* High = PDH
* Diagnostic in \>80% of dogs (\>95% when re-tested)
26
Compare and contrast Hyperadrenocorticism tests
27
What imaging techniques are useful for diagnosing PDH?
* CT, MRI, and US
* Pituitary tumor (macroadenoma or smaller)
* only 50% of PDH have detectable ass
* Bilateral adrenal hypertrophy (uniform / nodular)
* normal and abnormal glands overlap in size
28
What imaging techniques are useful for diagnosing ADH?
* US, CT
* Unilateral adrenal enlargement (usually nodular change)
* Atrophy of contra-lateral gland
* Not every adrenal mass is functional - possible misdiagnosis if functional testing is not done
29
What are the treatment options for PDH?
* Hypophysectomy
* Surgical
* removal/destruction of adenoma
* Difficult
* Medical Management
* Anti-adrenal therapy
* Pituitary Therapy
* Radiation
* Reserved for macroadenoma
* Slows tumor growth
* less effect on abnormal hormone production
30
What is an Adrenalectomy?
* Preferred treatment for ADH
* Pre-op imaging - asses metastasis and local invasion
* May require pre-surgical stabilization
* Peri- and post-operative complications
* Hemorrhage
* Thromboembolism
* Adrenal insufficiency
* Prognosis
* good is tumor is benign and easily removed
* malignant tumors = less favorable prognosis
31
What medications are available to treat hyperadrenocorticism?
* Trilostane
* Lysodren
* Ketoconazole
* Anipryl
32
How does Trilostane work to treat HAC?
* Inhibits synthesis for adrenal cortical steroids
* Reversible inhibitor of 3B-hydroxysteroid dehydrogenase
33
What is the dose of Trilostane? Adverse effects?
* 2 - 4 mg/kg/day (divided BID)
* Incremental increase as needed
* Minimal Adverse Effects:
* Transient vomiting, diarrhea and lethargy
* Rarely, hypoadrenocorticism may develop
* Acute adrenal necrosis (rare
34
How can trilostane therapy be monitored for effectiveness?
* **ACTH stimulation test**
* 10 - 14 days after starting
* 2 weeks after dose increase
* q3 months for the long term
* Target post-ACTH of 1.45 - 5.4 ug/dl
* up to 9.1 ug/dl is acceptable if clinical signs are controlled
* **Post-dose cortisol concentration**
* sample 4 - 6 hr post-dose.
* Cortisol ≥ 1.3 ug/dl excludes excessive suppression
* ≤ 2.9 excludes grossly inadequate control
* **Pre-dose Cortisol**
* pre-trilostane cortisol of 1.4 - 5 ug/dl correlates with effective control of clinical signs but not with post-ACTH stim cortisol concentrations
35
How does Lysodren work to control HAC?
* “mitotane”
* **Adrenocorticolytic** that acts by destruction of functional adrenal tissue
* Occasionally used as alternative to trilostane
36
How does Ketoconazole work to control HAC?
* Reversible inhibition of adrenal steroidogenesis (primarily glucocorticoids)
37
How does Anipryl control HAC?
* “selegiline' ‘L-deprenyl’
* Monoamine oxidase inhibitor (MAO) - reduces ACTH production
38
What is the Prognosis of HAC?
* PDH
* goal - improved quality of life
* CNS signs carry guarded prognosis
* ADH
* Benign adrenal tumors - good/excellent prognosis if removed
* Malignant tumors - guarded to poor prognosis due to local tissue invasion
39
Do cats suffer from hyperadrenocorticism?
* Considered uncommon to rare
* \>80% have PDH
* ~50% have microscopic pituitary tumors
* Iatrogenic - less common than dogs
* Differentials include DM and acromegaly
40
What is the common signalment of cats with HAC?
* Middle age or older (average - 10 yr)
* Higher incidence in females (70%)
* 80% of cats have insulin resistance and diabetes
41
What are the common clinical signs of Feline HAC?
* PU/PD
* polyphagia
* Diabetes that is “difficult to regulate”
* weight loss / failure to gain weight
* Lethargy; look ill
* Skin fragility
* alopecia
* failure to groom
* pendulous abdomen
42
What laboratory findings are common with Feline HAC?
* Limited Database
* CBC - no consistent abnormalities
* Serum chemistry
* hyperglycemia
* ALP not increased
* cats lack GC - induced ALP isoform
* Urinalysis
* Spec Gravity usually \<1.020
* Glucosuria
43
How is Feline HAC diagnosed?
* Screening test - same as Canine HAC
* ACTH stimulation test
* LDDS Test
* use 0.1 mg/kg (vs 0.01 mg/kg in dog)
* UCCR
* Differential testing - same as Canine HAC
* HDDS test
* Use 1.0mg/kg (0.1mg/kg in the dogs)
* Abdominal ultrasound
* Endogenous ACTH levels
44
What is the treatment for Feline ADH?
* Surgery best option if metastatic disease/invasion absent
45
What is the treatment for Feline PDH?
* Treatment of choice is controversial
* Surgery - Bilaeteral adrenalectomy
* Hypophysectomy
* Radiation Therapy
* Medical Therapy
* mitotane - cats more resistant
* Trilostane - limited information
* Ketoconazole - cats more resistant
46
What is the prognosis for Feline HAC?
guarded to poor
