Pathology Flashcards
Lack of most or all of the hormones from the anterior pituitary gland CC: “I don’t feel good.” – Growth hormone “My love life ”–FSH/LH “ .” – ACTH, TSH
Hypopituitarism (“Simmond’s disease”)
Simmond’s due to watershed infarction of the adenohypophysis during an obstetrical catastrophe.
A perennial point of confusion.
Sheehan’s
You have a tired, mousy, scrawny, unhappy patient. Spot morning cortisol (the screen) is less than 13 mcg/mL (as for many normals).
What test do you order?
ACTH stimulation test to rule ACTH insufficiency / adrenal insufficiency in / out
NOTE:
Please do NOT ask for a “spot ACTH” assay. And don’t kill your severely addisonian patient – the testing is stressful.
Too little cortisol produced after ACTH administration. Doesn’t get better no matter how often
you do it.
Adrenal insufficiency
The cortisol response is still low after an ACTH stimulation test, but it gets better each day.
Pituitary insufficiency
Your patient is thirsty and peeing a lot. The urine probably isn’t concentrated (SG
Give an injection of ADH (ADH stimulation test).
If the urine becomes concentrated, the diagnosis is pituitary (“central”) diabetes insipidus.
If the urine still won’t become concentrated, there’s a renal medullary problem (“nephrogenic diabetes insipidus”)
Your patient complains of failing libido and the history and ancillary testing indicate an organic cause.
Spot serum hormone levels as appropriate. What do you consider?
Serum prolactin level
- You have a short kid, or an older adult who “just doesn’t feel well.”
- Consider a screen for what? ex: spot IGF-I assays. Think about doing some stimulation test or other.
- Give this make a kid who’s short grow taller regardless of the cause.
- Caution: “Failure to thrive” from not being cuddled may also feature lowish levels
growth hormone
- Our patient is slowing down and you suspect hypothyroidism
- What do you screen with?
Free T4, free T3, and sensitive TSH.
Your patient is fat and/or hypertensive and/or diabetic and/or sad and/or crazy.
1st: 24 hour urine cortisol is one good screen for Cushing’s. Then use a dexamethasone suppression test.
Given at midnight, 2 mg of dexamethasone (the synthetic glucocorticoid) will suppress ACTH and hence blood cortisol levels measured in the morning.
Dx if…?
Suppressed by 8 mg but not by 2 mg?
Not suppressed by 8 mg?
Suppressed by 8 mg but not by 2 mg:
Pituitary adenoma
Not suppressed by 8 mg:
Some other cause of inappropriate ACTH / inappropriate cortisol production.
Your patient is sick and found to be hyponatremic. The urine sodium is higher than you’d expect.
Ask the patient to drink as little water as they can and see if things normalize
Note:
Don’t overdiagnose the syndrome of inappropriate ADH, especially in the presence of cachexia.
Galactorrhea-amenorrhea or something else that makes you think we have a pituitary problem.
Order what?

Spot FSH and LH
Looking at this diabetic / ugly adult / too-tall kid makes you wonder, “Could this be a growth-hormone producing pituitary tumor?”
What do you order?
Spot IGF-1
Note:
A serum GH itself is best used as a suppression test – if a glucose load fails to suppress=acromegaly / gigantism
Declining libido, menstrual irregularities?
What do you order?
Spot serum prolactin.
If it’s a prolactinoma, the concentration will usually be >100 ng/mL.
Most other entities will not give such a high prolactin.
High TSH and high T4?
Hyperthyroidism due to a TSH-producing pituitary lesion
T/F
Pressure on the optic chiasm from a mass (pituitary) can lead to bitemporal hemianopsia
TRUE
Pt presents with papilledema, HA, N/V…
Signs of incr intracranial pressure!
Can happen in pituitary adenoma patients.
Hemorrhage into the tumor --> Necrotic--> Swells--> Midbrain compressed--> Cavernous sinus syndrome
Pituitary apoplexy from hemorrhage into the tumor
Difference b/t normal ant. pituitary and adenoma on a slide?
The normal anterior pituitary has a variety of cells while the adenoma has a uniform population
Reticulin staining of the pituitary:
If it surrounds groups instead of individual cells=_______.
If really scrambled=_______.
hyperplasia
adenoma (reticulin also around BV)
TQ
In pituitary adenomas, what often mutates and loses self-feedback control?
G-protein signaling
may lead to proliferation, hormone syn and secretion
TQ
Pituitary adenoma genetics – ONCOGENES (gain-of-function mutations):
- Activating mutation
- GH-omas
GNAS
TQ
Pituitary adenoma genetics – ONCOGENES (gain-of-function mutations):
- Carney complex/germline mutation
- GH-omas
- Prolactinomas
PRKAR1A
TQ
Pituitary adenoma genetics – ONCOGENES (gain-of-function mutations):
- Amplified
- Marker for aggressive adenoma
Cyclin D1 (CCND1)
TQ
Pituitary adenoma genetics – ONCOGENES (gain-of-function mutations):
- Point mutation
- Pituitary carcinoma warning
HRAS
TQ
Pituitary adenoma genetics – ANTI-ONCOGENES (loss-of-function mutations):
- Germline
- Prolactinoma (less often GH or ACTH-omas)
MEN-1
TQ
Pituitary adenoma genetics – ANTI-ONCOGENES (loss-of-function mutations):
- Germline
- ACTH-omas
CDKN18
TQ
Pituitary adenoma genetics – ANTI-ONCOGENES (loss-of-function mutations):
- Germline
- Familial GH-omas
- Irish giants
AIP
TQ
Pituitary adenoma genetics – ANTI-ONCOGENES (loss-of-function mutations):
-If this promoter is methylated, an adenoma is more likely to be aggressive
RB
TQ
What are the two markers that correlate with tumor aggressiveness?
p53
Ki67/MIB-1
TQ
- Lights up the golgi
- Tends to be comprised of acidophils
- May only have a few granules
- Fibrotic post-tx
Prolactinoma
What is a pituitary stone?
calcifying prolactinoma
How do we take out a prolactinoma?
trans-sphenoidal resection
TQ
What are a few health problems faced by acromegalics?
-Big bones, famously the jaw (prognathism)
-Overdense (hyperostotic) or
osteoporotic bone
-Glucose intolerance / diabetes
-Gonadal dysfunction
-Myopathy / muscle weakness; congestive heart failure
-Hypertension
-Arthritis
-Goiter
-Sleep apnea
-Carpal tunnel
-High blood phosphate (IGF-1 promotes reabsorption)
-Clearly increased risk of some cancers, most notably colon
T/F:
The amount of stainable hormone in an HGH acidophil adenoma does not correlate with blood levels
True!
Densely granulated adenomas tend to be less aggressive than sparsely granulated adenomas.
Cushing’s syndrome vs. disease?
Cushing’s SYNDROME: Too much cortisol.
Cushing’s DISEASE: Too much cortisol as a result of an ACTH- producing pituitary adenoma.
-smallish “basophilic” tumors
ACTH-producing adenomas
TQ
- Old-time pt w/ Cushing’s disease had his adrenals removed instead of his pituitary adenoma :(
- The little bit of feedback that the high cortisol levels once gave is now gone.
- The pituitary ACTH-oma is now growing out of all control. He’s turned brown and is losing his eyesight (optic chiasm)
Dx?
Nelson’s syndrome
Carcinoma of the pituitary:
What is the real criterion for malignancy in an anterior epithelial pituitary tumor?
Metastases
TQ Pt presents w/: -weakness -lost libido/amenorrhea -wt loss -personality changes -muscle wasting -failure of lactation, diabetes insipidus, growth failure may also presents
Hypopituitarism
adenoma, infarct, empty sella
TQ
What are a few causes of hypopituitarism?
-Tumors (adenomas, craniopharyngiomas)
-Big Rathke cyst
-Brain trauma / subarachnoid bleeds
-After surgery / radiation
-“Pituitary apoplexy” (bleed into an adenoma)
-Ischemic necrosis / Sheehan’s
Empty sella syndrome:
-Primary (arachnoid & CSF herniate into the sella)
-Secondary (after damage from any cause)
-Hypothalamic lesions (rare, arcane)
-Sarcoidosis (anterior, posterior or both)
-TB meningitis
-Lymphocytic or granulomatous hypophysitis
-Genetic defects (remember PIT-1 – no GH, TSH, prolactin)
A large opening in the diaphragm on top of the sella allows arachnoid and CSF to move downward
Empty sella syndrome
Which twin has hypopituitarism due to a pituitary adenoma?
Hair loss, skinny
OR
No hair loss and overweight
No hair loss and overweight
How can you tell between simmonds or anorexia?
Ask pt if they like the way they look
Lymphocytes fill the adenohypophysis and the glandular cells are depleted
Lymphocytic hypophysitis
A family with no GH may have a mutation in which gene?
PIT-1 gene
What are two surprise causes of diabetes insipidus?
Sarcoidosis and eosinophilic granuloma (histiocytosis X)
- benign but locally destructive, and usually surgery is curative
- arise in or near the pituitary gland from Rathke’s pouch remnants
- stain catenin
Craniopharyngiomas
TQ
- Mostly children
- Look for calcifications, cell palisades
- Machine-oil cysts, layers of keratin
- Recall oral / tooth histology
Which gene mutation is assoc w/ this pathology?
Dx: Adamantinomatous craniopharyngioma
Gene: CTNNB1 (beta-catenin) mutations
TQ
- Mostly older adults
- Papillae lined by stratified squamous cells
Which gene mutation is assoc w/ this pathology?
Dx: Papillary craniopharyngioma
Gene: BRAF V600E mutations
Most familiar cause of secondary pituitary insufficiency?
Hypothalamic gangliocytoma (hamartoma)
Underworked ACTH-producing cells get a glassy look to their cytoplasm
Crooke’s hyaline change
Simple cysts in the pituitary region lined by columnar and/or squamous epithelium. Rarely, pressure can damage the pituitary.
Rathke cyst
17 yo old boy, HA behind left eye. N w/out vomiting, school performance declined. Growth stopped at 15. Angry outbursts…HA now 2-3 times per week…put on an anti-anxiety drug…HA continued…Not disabled
Bitemoporal hemianopsia, hyper pigmentation on shoulder, strong erections and no gynecomastia.
Labs: Hypothyroid but very high prolactin…so give thyroxine replacement…Has simmons
Imaging: 2 masses-one bone and other cystic in the sella (prolactinoma!)
Next biopsy trans-sphenoidally, lights up with MIB-1 (aggressive)
What gene is most likely altered?
CCND1: amplified if tumor aggressive
Gene review:
1. ___: rare…giant families. hGH predominant
2. _______: familial ACTH-omas
-MEN-1: proliferation marker, not mutated (multiple endocrine neoplasia), families
3. ____: genetic pituitary insuff
GNAS: sporadic HGH-omas
HRAS: cancer
- AIP
- CDKN1B
- PIT-1
Pituitary adenoma has expanded which direction..?
-______: bitemporal hemianopsia
- _______: hydrocephalus from midbrain compression
- _______: cavernous sinus syn–> opthalmoplegia (III, IV, VI), severe HA, stroke, venous stasis (eyelid swlled, proptosis), blood leakage into CSF
Upward
Posterior
Laterally
-Tired, can’t eat, feel sick:
lost finger to TB, hypothyroid–>tx, speaks slowly, depressed (endocrine), vomiting (intracrhaial)
- CT (big blob of contrast–>mass in head)…yellow mass, calcium cyst, machine oil
- Dx?
- Meds needed for hypopituitarism because of damage to hypothal, keratin from tumor–>meningitis
- Mutation: BRAF 600E
Papillary craniopharyngioma b/c no palisading
How do we stain C-cells?
calcitonin
small groups outside thyroid follicles
Black thyroid due to ?
antibiotic minocycline
Hyperplastic epithelium–>goiter could result from…(3)
- Graces
- Iodine deficiency
- Goitrogen/PTU effect
Colloid-filled follicles–>goiter could result from…(2)
- Idiopathic nodular goiter
- Extreme iodine excess
Anaplastic cells–>goiter could result from…(1)
cancer
Lymphocytes–>goiter could result from… (1)
Hashimoto’s
Foreign-body granulomas–>goiter could result from…(1)
DeQuervain’s
coxsackie virus–>macrophages attack thyroglobulin–>tender
Fibrous tissue–>goiter could result from…(1)
Riedel’s
Because they block oxidation of iodine & thus T4 production, they produce very cellular, colloid-poor thyroid glands
Goitrogens
cabbage, cassava, iodine def
Macrophages clean up a thyroid gland that’s been injured through palpation by lots of physicians
Palpation thyroiditis
-common, minor birth defect
-can grow over time and become troublesome
-Especially with the possible passageway to the mouth, they’re prone to get infected
-Removing them is generally a good idea

Thyroglossal duct cysts
TQ
- Slowing of mind and body
- Constipation
- Myxedema (increased tissue ground substance)
- Big tongue
- Schizophrenia, irritability, depression
- Weak heartbeat
- high LDL
- Slow reflexess
- Croaky voice
- Dry, cold skin
- Cold intolerance
- Hair thinning
Hypothyroidism
What are some causes of hypothyroidism?
- Thyroid agenesis
- Inborn errors of metabolism
- Other genetic mutations: TSH receptor
- After surgery / radiotherapy
- Autoimmuity (Hashimoto’s)
- Iodine deficiency
- Medications (lithium, para-amino salicylic acid)
- Secondary (lack of TSH / TRH, uncommon)
-extreme example of hypothyroidism in the young
-In much of the world, this results from maternal hypothyroidism
/ iodine deficiency.
-Diminished learning ability per year, and less brain power overall in the iodine-deficient population
-In the United States, inborn errors of metabolism and
the occasional agenesis of the thyroid get screened for soon after birth.

Cretinism
Iodine deficiency and goitrogen (cabbage)–>hyperplasia whereas iodine ______ gives huge, distended, follicles that prevent breakdown of thyroglobulin
toxicity
- Coursing of facial features
- Big tongue
- Hard to smile
Myxedema due to hypothyroid
Most adult-onset endogenous hypothyroidism in the US is due to what?
hint: brown thyroid from the mitochondria
Autoimmune thyroiditis, usually Hashimoto’s, in which T-cells attack and cause apoptosis of thyroid follicle cells
May see germinal centers and Hurthle cells (mitochondria)…may also see fibrosis
When discovered incidentally (workup of goiter), most Hashimoto’s are ______. When damage is rapid, release of thyroglobulin may actually produce hyperthyroidism (“Hashitoxicosis” or “Toximoto’s”).
euthyroid
A few percent of Hashimoto patients get an ____________ (probably a vasculitis).
encephalopathy