Clinical Associations and Pathoma Endocrine Flashcards
Psammoma Bodies: what do they indicate?
histological evidence of calcified papillations; found in cancers:
- Papillary carcinoma of thyroid
- Serous cystadenocarcinoma of ovary/serous endometrial carcinoma
- Meningioma
- Mesothelioma
Cherry red appearance of skin
Carbon Monoxide poisoning
Chocolate colored blood
Methemoglobinemia:
Fe2+ normally binds O2 in the blood;
Methemoglobinemia is when lots of blood iron is oxidized to Fe3+ and can’t bind O2 anymore
Things that can happen after a viral infection
- Subacute (deQuervain) Granulomatous Thyroiditis
-
Patient presents with a “hard as wood”, non-tender thyroid with dysphagia or respiratory compromise. What’s the differential?
= If the patient is a young female => Reidel fibrosing thyroiditis:
- chronic inflam with extensive fibrosis of thyroid; fibrosis extends to local structures
= If the patient is elderly => anaplastic carcinoma:
- undiff malig tumor of thyroid; very poor prognosis; invades local structures leading to dysphagia or resp compromise
patient presents with a tender thyroid and transient symptoms of hyperthyroid (hypocholesterolemia, hyperglycemia, tachycard, wt loss with incr apetite, heat intolerance, arrhythmia [elderly], tremor/anxiety, oligomenorrhea, diarrhea with malabs, staring gaze, decreased muscle mass, bone resorption w/ hypercalcemia)
Think: subacute (deQuervain) Granulomatous Thyroiditis
- after viral infection
- self-limited; will not progress to hypothyroid
what are the symptoms of hyperthyroid?
- hypocholesterolemia
- hyperglycemia
- tachycard (w/ incr CO)
- wt loss with incr apetite
- heat intolerance
- arrhythmia [elderly]
- tremor/anxiety
- oligomenorrhea
- diarrhea with malabs
- staring gaze
- decreased muscle mass
- bone resorption w/ hypercalcemia
what are the symptoms of hypothyroid?
- wt gain with normal appetite
- slow mental activity
- muscle weakness
- cold intol w/ decr sweat
- bradycardia (w/ decr CO)
- oligomenorrhea
- hypercholesterolemia
- constipation
patient presents with an anterior neck mass distinct from the thyroid, what could it be?
think: Thyroglossal duct cyst
- cystic dilation of thyroglossal duct remnant
patient presents with a mass at the base of the tongue, what could it be?
think: Lingual thyroid
- thyroid tissue persists at the base of the tongue (recall embryological development)
hypothyroid in infant/neonate: what is it, what’s the presentation, and what are causes?
think: Cretinism = presents with - mental retardation - short stature/skeletal abnorm - coarse face - big tongue - umbilical hernia = caused by: - maternal hypothyroid early on in pregnancy - thyroid agenesis - dyshormonogenic goiter (can't make thyroid hormone, often due to deficiency of peroxidase enzyme) - iodine deficiency
what is it called when you can’t make thyroid hormone?
dyshormonogenic goiter:
- can’t make thyroid hormone, often due to deficiency of peroxidase enzyme
What does thyroid peroxidase do?
- Oxidizes iodide to I or I+
- Organification: incorporates iodine into thyroglobulin molecule
- Coupling of diiodotyrosine and monoiodotyrosine to make T3 and T4
female presents with symptoms of hyperthyroid, diffuse goiter, exophthalmos, and pretibial myxedema. What is it?
Graves disease:
- IgG Ab stimulation of TSH Recept
- incr synthesis and release of thyroid hormone
- often seen in women of childbearing age
- most common cause of hyperthyroid
Labs:
- incr total and free T4; decr TSH, hypocholesterol, hyperglycemia
Tx:
- beta-blockers, Thioamide (block peroxidase), or radioiodine ablation
Feared complication: Thyroid storm
Patient with graves disease presents with arrhythmia, hyperthermia, vomiting, and hypovolemic shock, what is it?
Thyroid storm:
- increased catecholamines and hormone excess
Tx:
- PTU (peroxidase inhib AND inhib peripheral conversion of T4->T3)
- beta-blockers
- steroids
What is the mechanism of incr basal metabolic rate and sympathetic nervous system in hyperthyroid?
BMR -> from increased expression of Na/K ATPase
symp NS -> from incr production of beta1-adrenergic receptor
Multinodular goiter
- most commonly from iodine deficiency
- usually non-toxic
- toxic goiter: TSH- independent regions
hypothyroid in an older child or adult: what is it, what’s the presentation, what are the causes?
Myxedema
- features caused by glycosaminoglycans (GAGs) in connective tissue like skin, tongue, and larynx (leading to a deep voice)
causes:
- iodine deficiency (world)
- Hashimoto thyroiditis (developed world)
- drugs (Lithium)
- surgery/radioiodine ablation
patient initially presents with hyperthyroid before progressing to hypothyroid with decreased T4 and increased TSH;
what is it an which antibodies will be present?
Hashimoto thyroiditis
- autoimmune destruction of thyroid; mediated by HLA-DR5
- antithyroglobin and antimicrosomal antibodies will be present
- increased risk of B-cell lymphoma (marginal zone lymphoma from B-cells in marginal zone)
Microscopic examination of thyroid tissue shows chronic inflammation, germinal centers, and Hurthle cells; what is it?
Hashimoto thyroiditis
- Hurthle cells have more pink cytoplasm
What are the types of thyroid cancer, how is cancer distinguished from other abnormal thyroid tissue?
- more likely benign than malignant
- distinguish thyroid CA with radioactive 131I uptake study: there will be increased uptake in Graves of nodular goiter, decreased uptake in adenoma or carcinoma (do FNA biopsy)
- Follicular adenoma (benign)
- carcinoma:
Papillary (80%; good prog)
Follicular (malig; FNA cannot distinguish from follic adenocarc)
Medullary (malig; C cells; Familial: MEN 2A/B)
Anaplastic (malig; elderly; poor prognosis)
thyroid follicles surrounded by a dense capsule on microscopy
Follicular adenocarcinoma
- benign prolif of follicles (surrounded by fib capsule)
- non-functional; rare secretion of thyroid hormone
thyroid on microscopy show orphan annie-eyed nuclei on some cells and a nuclear groove on others, calcifications are noted; what is it?
Papillary carcinoma of thyroid
- most common thyroid cancer (80%)
- major risk of development is radiation in childhood (acne tx)
- calcifications on micro are psammoma bodies
- good prognosis, even with spread to cervical lymph nodes
What are the four types of carcinoma that tend to spread hematogenously
- Renal cell carcinoma -> renal vein
- Hepatocellular carcinoma -> hep vein
- choriocarcinoma
- follicular carcinoma of thyroid
Other carcinomas tend to have lymphatic spread
malignant proliferation of thyroid follicular cells; what is it?
Follicular carcinoma
- surrounded by fibrous capsule, but invades through capsule
- FNA CANNOT distinguish follicular carcinoma from adenoma
- hematogenous spread
microscopic examination of thyroid FNA shows malignant cells within amyloid stroma; what is it?
Medullary carcinoma of the thyroid
- malignant prolif of C cells;
- hi calcitonin -> hypocalcemia
- calcitonin deposits as amyloid within tumor
- Familial: MEN 2A/B
- assoc with mutation in RET oncogene -> prophylactic thyroidectomy
- 2A: medul carc of thyroid, pheochomocytoma, parathyroid adenoma
- 2B: medul carc of thyroid, pheochomocytoma, ganglion neuroma (esp of oral mucosa)
Female presents with galactorrhea and amenorrhea, what might cause this?
Think: prolactinoma (functional tumor of anterior pituitary)
- most common tumor of ant pit
- prolactin inhibits GnRH
- tx: Bromocriptine (DA agonist; recall that dopamine antagonizes the action of prolactin)
Male presents with decreased libido and headache, which might cause this?
Think: prolactinoma (functional tumor of anterior pituitary)
- most common tumor of ant pit
- prolactin inhibits GnRH
- tx: Bromocriptine (DA agonist; recall that dopamine antagonizes the action of prolactin)
Patient presents with bitemporal hemianopsia, headache, and/or hypopituitarism, what might cause these symptoms
Consider: mass effect - anterior pituitary tumor (could be functional or not)
A child presents with gigantism, what might cause this?
Pituitary adenoma of growth hormone
An adult presents with coarse facial features, large hands and feet, what other findins might be present and what is this? How is it diagnosed?
Acromegaly
- can also present with enlarged visceral organs: heart and tongue
- cardiac failure is the most common cause of death
- patients can also present with secondary diabetes (recall: GH inhibits cellular uptake of glucose)
- Dx: elevated GH and IGF-1 (IGF produced by liver is actually responsible for growth);
lack of suppression of GH with oral glucose
- Tx: Octreotide (somatostatin analogue; blocks ant pit response to GHRH);
GH receptor antagonist;
Surgery
What types of anterior pituitary tumors may arise and what would they cause?
Prolactinoma (most common)
Growth hormone adenoma -> gigantism/acromegaly
ACTH adenoma -> Cushing
TSH, LH, FSH rare
What are some complications of pituitary adenoma?
Mass effect/functional adenoma
apoplexy: bleeding into pit adenoma -> compress and destroy tissue -> hypothyroid
What are some causes of hypopituitarism?
- pituitary adenoma (adult)
- apoplexy: bleeding into pit adenoma -> compress and destroy tissue
- craniopharyngioma (child) -> arrises commonly in region of sella and can compress and destroy pituitary
- Sheehan syndrome (common in preg; pit can double in size then infarct; present with poor lactation lost pubic hair
- Empty sella syndrome
- secondary from trauma
- primary from congenital defect leading to herniation of arachnoid and CSF into sella compressing and destroying pituitary
A woman presents post-partum with poor lactation and loss of pubic hair, what might be the cause?
Sheehan syndrome
- pituitary infarct is more likely after pregnancy due to increased size without much increase in vascularization
- presents with symptoms of low FSH/LH