Thyroid, Parathyroid, and Adrenal Flashcards
(28 cards)
Which surgeon was awarded the nobel prize in physiology or medicine for his work on the physiology, pathology, and surgery of the thyroid gland?
Emil Kocher
What congenital anomaly arises from the formation of the thyroid gland?
Thyroglossal duct cyst
- The medial thyroid anlage descends from the base of the tongue cia the thyroglossal duct cyst at week 3 or 4 of gestation
- Removal is accomplished with the sistrunk operation
- also removes the central portion of the hyoid bone
The arterial supply of the thyroid arises form _________
Aorta, External carotid, thyrocervical trunk
A thyroid IMA artery arises directly from the aorta or innominate artery in 1 to 4% of cases
In what location, relative to the inferior thyroid artery is the RLN found
- Medial or posterior
- Lateral or anterior
- Passing between branches of ITA
RLN couyrses within the tracheoesophageal groove after emerging from the vagus nerve at the level of the aortic arch
ALthough injury to the RLN results in hoarseness or airway obstruction, injury to the SLN results in a more subtle injury, affecting the ability to ___________
Speak loudly or sing high notes
- The external branch of the SLN lies on the inferior pharyngeal constrictor muscle and descend alongside the Superiot thyroid vessels beofre innervating the Cricothyroid muscle
Roles of T3 and T4
- Maintaining normal hypoxic abd hypercapnic drive in the respiratory center
- Regulate GI motility
- Regulate bone and protein turnover
- speed of muscle contraction and regulation
- Hepatic gluconeogenesis
- Cholesterol sythesis
- antestinal glucose absorption
In North americ, hyperthyroidism is most often caused by _________
Diffuse toxic goiter(Graves disease)
60-80% of cases
Subtotal or total thyroidectomy is preferred for the the treatment of graves disease in___________-
- When radioactive iodine therapy is contraindicated
- When the goiter is large or airway obstruction appears imminent
- In patients with demonstrated poor compliance with anti-thyroid medications
- Childbreaing who desire to have children in the near future
What is the recommendedcourse of action when FNAB of thuroid nodule is follicular neoplasm
Lobectomy
- Follicular neoplasm
- less aggressive than papillary
- unilateral lobectomy is indicated
Diseases associated with germline mutations in the RET tyrosine kinase receptor gene
- MEN 2A
- MEN 2B
- Hirshcprung
- FMTC (familial medullary thyroid cancer)
CHildren exposed to the chernobyl disaster in 1986 subsequently demonstrated an increased incidence of which thyoird cancer
Papillary thorid cancer
80% of all thyroid malignancues and is the predominant thyroid cancer in children and indicviduals exposed to radiation
The recommended treatment for an otherwise healthy 50 year old man with a 2cm PTC in the left love diagnosed by FNAB is
Total left lobectomy and subtotal right lobectomy
- Unifocal PTC greater than 1cm in diameter
An adoelscent patient with a thyroid mass undergoes FNAB which returns as MCT. What other diseases should be scrrene before treatment is undertaken
- Hyperparathyroidism
- Pheochromocytoma
- Mucocutaneous ganglioneuromas
- MArfanoid habitus
MCT can be spontanesous (7%) or familial (25%) in MEN2,
- MEN2A
- pheochromocytoma, hyperPTH
- MEN2B
- pheochromicytoma, marfanoid habitus, mucocutaneous ganglioneuromas
An asymptomatic child with normal PE os found to harbor a mutaion in codon 918 of the RET tyrosine kinase receptor, compatible with MEN2B. UTZ is unremarkable and serum calcitonin is normal. What course is indicated
Total thyroidectomy
- Children with mutations at codon 634 (MEN2A)
- thyroidectomy before age 5
- CHildren with mutations at codon 918 (MEN2B)
- before age 1
Postoperative complications within 24 hours of thyroid surgery
- Hypocalcemia
- Dyspnea
- Dystonia
- vocal cord paralysis
A patient with primary hyperPTH undegoes neck exploration where 4,normal appearing glands are found, What are the possible locations of an additional supernumerary gland
- Thymus(most common)
- tracheoesophageal groove
- thyroid gland
- mediastinum
A 70 year old woman with early dementia but otherwise good physical health has an elevated PTH level and a sestamibi scan which localizes a single focus or increased activity to the left lower neck. An ultrasound confirms an enlarged gland in the same area. What treatment is likely to provide the best outcome?
Unilateral, mini incision parathyroidectomy under local anesthesia
- Localization studies such as sestamibi scans have been shown ton allow limited operations, including those utilizing mini incisions
Intraoperative, rapid PTH assays provide guidance that all hyperfunctioning glands have been removed during parathyroidectomy. What criterion is used to indicate satisfactory resolution of the hyperPTH during the procedure?
Greater than 50% fall in PTH level within 10 minutes of removal of parathyroid tissue
A patient with persistent ulcer disease is diagnosed with a gastrinoma. Serum chemistry studies indicate hypercalcemia and an elevated PTH level is documented. What is the indicated course of treatment?
Neck exploration for removal of the parathyroid adenoma
- In patients with MEN 1, hyper PTH should be corrected befre treatment of the gastrinoma becaue resolution of hypercalcemia may allow gastrin levels to fall to normal
Suggestive findings of a parathyroid carcinoma
- Elevated serum calcium >14mg/dl
- elevated PTH level >5x than normal
- palpable neck mass
A 50 year old healthy-appearing man undergoes evaluation of persistent hypertension. Serum chemistries reveal hypokalemia (<3.2). and imaging studies reveal a unilateral adrenal mass. What is the likely diagnosis?
Hyperaldosteronism (Conn syndrome)
- 1% of HTN patinets
- common in middle aged individuals
- single adenoma of the adrenal cortex
- refractory to emdical treatment
- hypokalemia, but may be seen normokalemic individuals
A 35 year old woman undergoes an evaluation for infertility. She ahs gained 100 lb in the past year, is hypertensive, and is bordeline diabetic. She also complains of easy bruising. Her serum chemistries are normal with exception of an elevated glucose. Imaging studies reveal a unilateral adrenal mass. What is the likely diagnosis?
Primary hypercortisolism (Cushing syndrome)
- refers to any cause of hypercorticolism caused by either an adrenal source or exogenous administraion of steroids
- Cushing disease
- refers only to an ACTH-secreting adenoma of the pituitary gland
- Adrenalectomy is curative for primary adrenal tumors or for adrenal hyperplasia that persists despite efforts to resect a pituitary tumor
Imaging techniques useful to localize a pheochromocytoma
-
CT scan
- detected 85 to 95% accuracy
- avoid IV contrast
-
MRI scan
- tumors tends to enhance on T2 weighted images
-
Metaiodobenzylguanidine (MIBG) scan
- similar to NE
Pheochromocytoma can secrete excess amounts of all of the following
Dopamine, Norepinephrine, Epinephrine
