Endocrine associated stuff Flashcards
According to the article “Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7. - Does the presence of vascular invasion in adrenal tumors affect the morbidity/mortality?
No. Currently ruling in/out vascular invasion may change the surgical approach but at this time no significant difference has been seen in morbidity/mortality of those with or with out direct vascular invasion.
Which type of adrenal tumor is more likely to be associated with vascular invasion?
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Pheochromocytomas.
Adrenal tumors have been shown in multiple studies to have a predilection for left vs right sided, which side is the most commonly affected?
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Left-sided is more common. In this particular study 65% were left sided.
Which adrenal tumor has been reported to invade the hypaxial and epaxial musculature?
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Pheochromocytomas.
Is the presence of a peripheral contrast-enhancing rim in late phase CT images associated with a more benign or aggressive process when classifying adrenal tumors?
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Benign. Presence of a peripheral contrast enhancing rim is associated with a fibrous capsule or pseudo capsule which is recognized more frequently in well-differentiated and low-grade tumors.
Malignant pheochromocytoma are considered the most aggressive in terms of vascular invasion. What percentage have direct invasion into the adjacent vasculature and what percentage have distant metastasis?
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Pheochromoctyomas are reported to have up to 85% direct invasion and up to 40% have distant metastasis.
Is there a difference in mean attenuation when comparing a pheochromocytoma and adrenal adenocarcinoma? If so which is associated with a higher HU
“Comparison of computed tomographic and pathologic findings in 17 dogs with primary adrenal neoplasia” Vet Rad/US Vol. 00, No.0 2014 pp 1-7.
Pheochromocytomas have a higher mean attenuation than adrenal adenocarcinomas. Pheo- 44.5 HU AAC- 28.2 HU
In the article: US measurements of adrenal glands in cats with hyperthyroidism. VRU 53.2 (2012).
What were their findings in control vs treated/untreated hyperthyroid cats?
No difference in adrenal gland shape - bean/ovoid/elongated shape with hyperechoic halo between healthy/hyperthyroid cats
Adrenal gland size was larger in dorsoventral and craniocaudal directions for hyperthyroid cats (up to 20% larger). No signficant difference between treated/untreated cats.
Hyperthyroid cats were more likely to have hyperechoic foci
In the article: US measurements of adrenal glands in cats with hyperthyroidism. VRU 53.2 (2012).
What are measurements for healthy cat adrenal glands versus hyperthyroid (treated/untreated) cats?
Up to 20% increase in adrenal gland size when hyperthyroid.
healthy cat: CrCa: 10mm DV: 3.5-4mm
Hyperthyroid cat: CrCa: 11.1-12.2 DV: 4.5-4.9
(up to increase in 1.6-1.6mm in length, 0.8-0.9 height)
What were causes of hyperechoic foci in adrenal glands in cats?
In the article: US measurements of adrenal glands in cats with hyperthyroidism. VRU 53.2 (2012).
fat deposition, small hemorrhage, microscopic calcifications
What is theory behind increased adrenal gland size in cats with hyperthyroidism?
US measurements of adrenal glands in cats with hyperthyroidism. VRU 53.2 (2012).
Increased episodes of cortisol secretion, as well as increased amount of cortisol secreted per secretory episode.
High levels of thyroxine –> increased clearance of cortisol –> increased ACTH –> increased work on adrenal gland.
Hyperthyroid cats are more stressed out –> increased activation of hypothalamic pituitary adrenocortical axis
Differentials for adrenomegaly in cats? What imaging characteristics help distinguish between conditions (if any)?
US measurements of adrenal glands in cats with hyperthyroidism. VRU 53.2 (2012).
Hyperthyroidism, adrenal hyperplasia, hyperadrenocorticism, hyperaldosternosim, acromegaly, tumors
Bilateral enlargement: hyperadrenocorticism, hyperaldosternism, acromegaly, hyperthyroidism
Unilateral enlargement: tumors - most frequently will be >1cm larger than normal (normal is 10mm - usually will be >2cm)
In this study: Prevalence of incidental thyroid nodules in US studies of dogs with hypercalcemia. VRU 56.1
14/91 dogs had thyroid nodules, which had a variable histologic findings (adenoma, cyst, hyperplasia, carcinoma) What were there main US characteristics?
well-defined
Most were hypoechoic (some were mixed)
intact/distorted (50/50) capsular margins
Lots of overlap between the histologic findings
What were results of histopath of some of these incidental thyroid nodules?
Prevalence of incidental thyroid nodules in US studies of dogs with hypercalcemia. VRU 56.1
cyst, adenomas, adenocarcinoma, nodular hyperplasia
What are defining US characteristics of thyroid adenoma and adenocarcinomas?
Prevalence of incidental thyroid nodules in US studies of dogs with hypercalcemia. VRU 56.1
Lots of overlap between the two in early stages - small, well defined, hypoechoic nodules
Later stages - carcinomas: hypoechoic, inhomogeneous, mvariable margination, invasion or regional tissues, high vascularization and mineralization
In humans, what percentage of patients with hyperparathyroidism have co-existing thyroid disease?
40% -not sure if there is a link bewteen hyperparathryoidism and thyroid cancer
What percentages represent each pattern of thyroid uptake in cats?
Unilateral
Bilateral-asymmetric
Bilateral-symmetric
Multifocal
Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.
Unilateral - 30%
Bilateral asymmetric - 50%
Bilateral symmetric - 10%
Multifocal -
What was prevalence of ectopic thyroid tissue and thyroid carcinoma in Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.?
Ectopic thyroid - 4%
Carcinoma - 2%
What was considered a normal thyroid:salivary and thyroid:background in Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.
Thyroid:salivary
What was sensitivity for thyroid:salivary ratio and thyroid:background in
Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.
Thyroid:salivary >1.5 was 0.987
Thyroid:background >6.4 was 0.961
How does the sensitivity of thyroid:salivary and thyroid:background ratio compare to endocrine testing (T4)?
Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.
Thyroid:salivary sensitivity: 98%
Thyroid:background: 96%
Total T4: 91%
What does effect of methimazole have on thyroid uptake?
In the different studies - how does TSH levels between normal/hyperthyroid cats and methimazole differ?
Thyroid scintigraphy findings in 2096 cats with hyperthyroidism. VRU 56.1.
Nieckarz suggested that methimazole can lead to increased uptake (increased T/S) for up to 3weeks after discontinuation in normal cats. After methimazole is discontinued the cats became hypothyroid - and TSH is secreted in high levels to increase T4 levels.
Fischetti et al - reported that methimazole did not increase T/S ratio in hyperthyroid cats. Cats with hyperthryoidism will have low TSH levels, so even after discontinuation of methimazole - TSH does not increase