Adrenal Glands Flashcards
Which adrenal gland tends to be bigger in dogs?
The left adrenal gland tends to be bigger
What is the difference in shape between the right and left adrenal gland?
The left adrenal gland - is usually bilobed
The right adrenal gland - can be comma shaped
How do the cat adrenals differ from the dog adrenal glands?
In cats the adrenal glands tend to be more oval to cylindrical than in dogs and are more uniform in both size and shape.
Does the phrenicoabdominal artery and vein pass dorsal or ventral to the adrenal gland?
Phrenicoabdominal artery - dorsal
Phrenicoabdominal vein - ventral
What does mineralization of the adrenal glands in cats mean?
Nothing, it is an incidental age related change.
What does mineralization of the adrenal glands in dogs mean?
In dogs this finding has more significance, than in cats. Mineralization associated with adrenal gland enlargement suggest adrenocortical tumor.
How do the adrenal glands look like with PDH?
They can be:
- normal
- bilaterally enlarged
- unilaterally enlarged
- adrenal nodules/masses with PDH have been reported
PDH accounts for ~80% of Cushing’s disease.
Adrenal tumors account ~ 20% of Cushing’s disease.
What are common adrenal tumors?
Primary adrenal neoplasia:
- Adrenocortical adenoma
- Adrenocrotical carcinoma
- Pheochromocytoma
Metastatic disease
What are some sonographic findings with adrenal tumors?
-HAC is functional
A nodule or mass causing unilateral enlargement of the adrenal gland is usually identified.
If the tumor is hormonally active, the contralateral adrenal gland may be difficult to identified because of atrophy.
One study suggests that adrenal dependent hyperadrenocorticims (HAC) is more likely if the adrenal glands are asymmetric and the maximal thickness of the smaller glands is < 5mm. However, other studies report that the contralateral adrenal gland can also be normal.
Adrenal tumors are sometimes non-functional, cortisol secreting or destructive, leading to hypoadrenocorticims, which contributes to the difficulty in diagnosing them.
Studies indicate that adrenal tumor is more likely if the adrenal size is > 2cm in diameter. If unilateral adrenal gland enlargement between 1-2 cm exists, then there could be either adrenal tumor or PDH.
What is the biological behavior of adrenal tumors?
All adrenal tumors have been found to be locally invasive to the kidney, renal artery, renal vein and are known to metastasize to distant sites.
Why are biopsies of pheochromocytoma not recommended?
Because hemorrhage, hypertensive crisis or arrhythmic episodes can occur.
What measurement is suggestive of small adrenal gland?
< 3.2 mm thick was strongly suggestive of hypoadrenocorticism when compared to healthy dogs.
What can adrenal tumors secrete?
Cortisol
Aldosterone - a polymyopathy due to hypokalemia and systemic hypertension has been observed with this disorder
Sex hormones
- progesterone result in similar signs as PDH and can also result in DM
- androgen secreting tumors can result in behavioral changes
What are some non-neoplastic masses of the adrenal glands?
Hematomas, granulomas, cysts and abscess are described in human literature.
Infectious - toxoplasmosis, crypto coccus, coccidiocomycosis, and histoplasmosis are known to involve the adrenal glands in small animals
Acute intoxication and systemic bacterial infections are also known to produce inflammatory edema , necrosis and hemorrhage of the adrenal glands. However, there are no described ultrasound findings in these disorders.
What is negative side effect of mitotane?
It can cause adrenal necrosis, which appears ad hypo echoic areas within the adrenal gland. These can disappear within several weeks.
Additionally the size of the adrenal gland has been reported to decreased after mitotane administration.
