Chapter 15: Endocrine Flashcards
Prolactinoma, GH cell adenoma, ACTH cell adenomas are all examples of what?
A pituitary adenoma - Benign tumor of the anterior pituitary
What Sx would a patient with a non-functional pituitary adenoma present with (3)?
- BITEMPORAL HEMIANOPSIA - compression of the optic chiasm
- Hypopituitarism: due to compression of normal pituitary tissue
- HA
What is the most common type of pituitary adenoma?
Prolactinoma
What are the presenting symptoms of a Prolactinoma?
Females: galactorrhea, amenorrhea
Males: decreased libido, headache
What is the treatment for a prolactinoma?
Dopamine agonists (Bromocriptine or cabergoline): - suppresses prolactin production (tumor shrinks) or surgery for larger lesion
How will a Growth hormone cell adenoma presentation differ in children vs adults?
Children: Gigantism - increased linear bone growth (epiphysies are not fused)
Adults: Acromegaly - enlarged bones of hands, fee, jaw; growth of visceral organs leading to dysfunction (Cardiac failure); enlarged tongue
-Secondary diabetes mellitus is often present
How is a GH cell adenoma diagnosed?
Elevated GH and insulin growth factor-1 (IGF-1) levels along with lack of GH suppression by oral glucose
What is the treatment of a CH cell adenoma?
Octreotide (somatostatin analog that suppressed GH release
GH receptor antagonist
Surgery
What will be the major complication associated with ACTH cella denomas?
Cushing sydnrome
How much of the pituitary parenchyma must be lost before symptoms will arise from hypopituitarism?
75%
Pituitary adenomas in adults or craniopharyngiomas in children will cause what pituitary issue due to mass effect or pituitary apoplexy?
Hypopituitarism
What is Sheehan syndrome?
Pregnancy-related infarction of the pituitary gland.
- Gland doubles in size during pregnancy, but blood supply does NOT increase significantly; blood loss during parturition precipitates infarction.
How will a mother with Sheenhan syndrome present?
Poor lactation, loss of pubic hair [secondary to decreased LH], and fatigue
-Will have hypopituitarism
What is Empty sella syndrome?
Congenital defect of the sella
- herniation of the arachnoid and CSF into the sella compresses and destroys the pituitary gland
- Pituitary gland is “absent” (empty sella) on imagine
- Is a cause of hypopituitarism
What is Central Diabetes Insipidus?
ADH deficiency
-Due to hypothalamic or posterior pituitary pathology
A patient presents with polyuria, polydipsia, hypernatremia, high serum osmolality, and low urine osmolality and specific gravity. He is is found to have an issue with the posterior pituitary gland. What does he have?
Central diabetes insipidus
How do you diagnose Central Diabetes Insipidus?
Water deprivatoin test FAILS to increase urine osmolality
How do you treat Central Diabetes insipidus?
Desmopressin (ADH analog)
What is nephrogenic diabetes insipidus?
Impaired renal response to ADH
- Due to inherited mutations or drugs [lithium, demeclocycline]
- No response to desmopressin
What is Syndrom of inappropriate ADH (SIADH) Secretion?
Excess ADH secretion
What causes SIADH?
Most often due to ectopic ADH production [small cell carcinoma of the lung]
-other causes: CNS trauma, pulmonary infection, and drugs [cyclophosphamide]
A patient presents with hyponatremia and low serum osmolality. The patient also has mental status changes and seizures. The patient is found to have excessive ADH secretion and a problem with the posterior pituitary. What do they have?
SIADH secretion
What is the treatment for SIADH secretion
Free water restriction or demeclocycline - blocks effect on ADH
What is a thyroglossal duct cyst, and where does it come from?
- Cystic dilation of thyroglossal duct remnant
- a persistent thyroglossal duct that did not involute - which then underwent cystic dilation.
- Presents as an anterior neck mass
*How does hyperthyroidism increase basal metabolic rate?
Due to increased synthesis of Na/K ATPase
*How does Hyperthyroidism increase sympathetic nervous system activity?
Due to increased expression of B1-adrenergic receptors
What are the 2 symptoms most characteristic of Hyperthyroidism?
Hypocholesterolemia
Hyperglycemia [due to gluconeogenesis and glycogenolysis]
What is Graves disease?
- Autoantibody [IgG] that stimulates TSH receptor (type II hypersensitivity)
- Leads to increased synthesis and release of thyroid hormone
- A type of hyperthyroidism
A patient present with hyperthyroidism, Diffuse goiter, exophthalmos and pretibial myxedema. Histology of the thyroid shows irregular follices with SCALLOPED COLLOID and chronic inflammation. What do they have?
Graves!
What is the most common cause of hyperthyroidism?
Graves Disease
- Classically occurs in women of childbearing age (20-40 years old)
Laboratory tests come back with an increased total and free T4; Decreased TSH; Hypocholesterolemia, and an increased serum glucose. Histological examination of the thyroid reveals irregular follices with scalloped colloid. What does the patient have?
Graves!
How do you treat Graves Disease?
Beta blockers
Thioamide - Blocks peroxidase
Radioiodine ablation
What is THYROID STORM
- is a potentially fatal complication
- Due to elevated catecholamines and massive hormone excess, usually in response to stress [surgery, childbirth]
- Presents as arrhythmia, hyperthermia, and vomiting with hypovolemic shock
What is the treatment for thyroid storm?
Propylthiouracil (PTU), Beta blcoers, and steroids
-*PTU inhibits peroxidase-mediated oxidation, organification, and coupling steps of thyroid hormone synthesis, as well as peripheral conversion of T4 to T3
What is a multinodular goiter
- enlarged thyroid gland with multiple nodules
- Due to relative iodine deficiency
- Usually nontoxic - euthyroid
- Rarely, regions becomes TSH-independent leading to T4 release and hyperthyroidism (“Toxic goiter”)
What is Cretinism?
-Hypothyroidism in neonates and infants
What characterizes cretinism?
-Mental retardation, short stature with skeletal abnormalities, coarse facial features, enlarged tongue, umbilical hernia.
What are the causes of Cretinism?
- Maternal hypothyroidism during early pregannce
- Thyroid agenesis
- Dyshormonogenetic goiter
- Iodine deficiency
What causes the dyshormonogenetic goiter seen in Cretinism
Is due to a congenital defect in thyroid hormone production;
-Most commonly involves THYROID PEROXIDASE
What is myxedema?
-Hypothroidism in older children or adults
What is the most causes of Myxedema?
- Iodien deficiency
- Hashimoto thyroiditis
- Other: drugs [lithium], surgical removal; radioablation of the thyroid
What are the most common symptoms of Myxedema?
- Based on decreased basal metabolic rate and decreased sympathetic nervous system activity
- Myxedema: accumulation of glycosaminoglycans in the skin and soft tissue; results in a deepening of voice and large tongue
- Hypercholesterolemia;
- Others: Weight gain despite normal appetite, slowing of mental activity, muscle weakness, cold intolerance with decreased sweating, bradycardia with decreased cardiac output, leading to shortness of breath and fatigue, oligomenorrhea, constipation
What is Hashimoto Thyroiditis?
- Autoimmune destruction of the thyroid gland; associated with HLA-DR5
- Most common cause of hypothyroidism in regions were iodidne levels are adequate
A patient presented iniitally with hyperthyroidism (due to follicular damage). This then pregressed to hypothyroidism, with Decreased T4 and increased TSH.
Antithyroglobulin and antimicrosmal antibodies are present. What do they have?
Hashimoto Thyroiditis
A histology slide shows Chronic inflammation with germinal centers and Hurthle cells (eosinophilic metaplasia of cells that line follicles). What do they have?
Hasimoto Thyroiditis
A patient presents with Hasimoto Thyroiditis. Which disease are they at risk for and how does it present?
- B-cell (marginal zone) lymphoma
- Presents as an enlarging thyroid gland late in disease course
A patient presents with a TENDER THYROID with transient hyperthyroidism a week after getting over a nasty viral infection. He has some time of self-limiting Granulomatous thyroiditis. What do they most likely have and what will it progress to?
- Subacute Granulomatous (De Quervain) Thyroiditis
- This is self-limiting - this does NOT progress to hypothyroidism
Patient presents with hypothyroidism with a “HARD AS WOOD”, NON-tender thyroid gland. Biopsy shows chronic inflammation with extensive fibrosis of the thyroid. Fibrosis extends (sometiems) to local structs, but there are no malignant cells present. What is the Dx?
Reidel Fibrosing Thyroiditis
How will thyroid neoplasms present?
-Usually as a distinct, solitary nodule that is more likely to be benign than malignant.
How can we differentiate and characterize nodules:
- BIOPSY IS PERFORMED BY FINE NEEDLE ASPIRATION.
- I-131 radioactive uptake studies are useful to further characterize nodules.
- Increased uptake (‘hot’ nodule) is seen in Graves disease or nodluar goiter.
- Decreased uptake (‘cold’ nodule) is seen in adenoma and carcinoma. OFTEN WARRNTS BIOPSY
- Increased uptake (‘hot’ nodule) is seen in Graves disease or nodluar goiter.
What are the 5 types of Throid neoplasias?
Follicular adenoma Papillary carcinoma Follicular carcinoma Medullary carcinoma Anaplastic carcinoma
Histo slide reveals a Benign proliferation of follicles surrounded by a FIBROUS CAPSULE
which is nonfunctional. (some, rarely may secrete thyroid hormone). What do they have?
Follicular adenoma
What is the most common type of thyroid carcinoma (80%)?
Papillary carcinoma
A patient was exposed to ionizing radiation in childhood - which type of carcinoma is he at risk for now?
Papillary Carcinoma
Histology reveales papillae lined by cells with clear “orphan Annie eye” nuclei and nuclear grooves. (The papillae are often assoicated with psammoma bodies). This was found to spread to cervical (neck) lymph nodes but still has an excellent prognosis. What do they have?
Papillary Carcinoma