Chapter 15 - Endocrine Flashcards
How do you treat a prolactinoma?
Dopamine agonists! Specifically bromocriptine or cabergoline.
Common endocrine abnormality that develops with a growth hormone cell adenoma?
Secondary diabetes mellitus. Due to GH induced liver gluconeogenesis.
How to treat a Growth Hormone cell adenoma?
Octreotide, which is a somatostatin analog (somatostatin normally inhibits GH release).
What is Sheehan syndrome and how does it present?
Hypopituitarism following pregnancy, due to increased size of the gland and same amount of vasculature. Blood loss during parturition leads to infarction.
Presents as poor lactation and loss of pubic hair!
Common drugs that cause nephrogenic diabetes insipidus?
Lithium and demeclocycline (antibiotic)
Common cause of SIADH?
Small cell carcinoma of the lung
How to treat SIADH?
Water restriction or demeclocyline (induces Diabetes insipidus).
What type of embryologic remnant can present as an anterior neck mass?
A thyroglossal duct cyst (cystic dilation of thyroglossal duct remnant).
What type of embryologic remnant can present as a base of tongue mass?
Lingual thyroid!
What are the two main results of hyperthyroidism and how do they happen?
- Increased basal metabolic rate - increased synthesis of Na-K ATPase
- Increased sympathetic activity - increased expression of B1-adrenergic receptors
What changes in cholesterol and blood sugars are seen in hyperthyroidism?
Hypocholesterolemia and hyperglycemia (due to gluconeogenesis and glycogenolysis).
What is Graves disease?
Autoantibody that stimulates the TSH receptor (type II hypersensitivity).
What are the non-thyroid symptoms of Graves and what causes them?
Exophthalmos and pretibial myxedema.
Due to TSH receptors present on fibroblasts behind the eye and overlying the shin. Leads to glycosaminoglycan buildup, inflammation, fibrosis, and edema.
Irregular follicles with scalloped colloid and chronic inflammation on histo = ?
Graves disease
Treatment of Graves disease?
b-blockers, thioamide (blocks peroxidase necessary for synthesis of T3/T4), and radioiodine ablation.
How do you treat thyroid storm complication of Graves disease?
Give propythiouracil (PTU), which inhibits peroxidase (necessary for oxidation, organification, and coupling steps of thyroid hormone synthesis, as well as peripheral conversion of T4 to T3). Also b-blockers and steroids.
What is Cretinism?
Hypothyroidism in neonates (presents as mental retardation, short stature, coarse facial features, enlarged tongue, umbilical hernia).
What is the most common cause of dyshormonogenetic goiter leading to cretinism?
Congenital defect involving thyroid peroxidase –> cannot make T4/T3!
What is Myxedema?
Hypothyroidism in older children/adults. See deepening of voice and large tongue due to accumulation of glycosaminoglycans in the skin and soft tissue.
What is Hashimoto Thyroiditis and what is it associated with?
Autoimmune destruction of the thyroid gland, associated with HLA-DR5
Chronic inflammation with germinal centers and Hurthle cells (eosiniphilic metaplasia of cells that line follicles) of the thryoid = ???
Hashimoto Thyroiditis
What neoplasm is Hashimoto thyroiditis associated with?
Increased risk for B-cell (marginal zone) lymphoma.
What often presents as a tender thyroid?
Subacute Granulomatous (De Quervain) thyroiditis. Follows a viral infection, presents as hyperthyroidism that is self-limited.
What often presents with a “hard as wood”, nontender thyroid?
Reidel Fibrosing Thyroiditis.
Mimics anaplastic carcinoma, as fibrosis often spreads, but patients are younger and malignant cells are absent.
