Exam 2 Path Flashcards
Pituitary adenoma:
Female vs male presentation of lactotroph adenoma
Females present at a young age with primary amenorrhea
Males present at an older age with mass effect
*PRL is a more common workup in young females vs males, therefore caught earlier
Pituitary adenoma type?
stromal hyalinization w/ psammoma bodies,
dense calcifications can become pituitary stones
Lactotroph adenoma
Pituitary adenoma:
Effect of a somatotroph adenoma in a younger child who is still growing
Gigantism (very tall)
*GH effect on bone prior to closure of epiphyseal plates
Pituitary adenoma:
Effect of a somatotroph adenoma in an adult who has finished growing
Acromegaly (thicc bones)
- GH effect on bone after closure of epiphyseal plates
- large face and hands, jaw, nose, lips, organs
Diagnostic test for pituitary somatotroph adenoma?
Measure serum IGF-1 (more stable and predictable)
Oral glucose tolerance test
*oral glucose would normally inhibit GH, if IGF-1 remains high after ogt then suggestive of somatotroph adenoma
Diagnostic test for corticotroph adenoma?
*in setting of high ACTH
Dexamethasone suppression test: pituitary corticotroph adenoma will be suppressed (decreased ACTH), ectopic ACTH will not be suppressed
*inferior petrosal sinus sampling would also show increased ACTH in setting of pituitary adenoma
Diagnosis?
Elevated ACTH and hyperpigmentation
Surgical hx = bilateral adrenalectomy
Nelson syndrome
removal of adrenals leads to increase in ACTH, which stilmulates MSH (melanocyte stimulating hormone), leads to hyperpigmentation
Paraneoplastic syndromes:
Ectopic ACTH releasing tumor type?
Small cell lung cancer
*causes cushing syndrome
- cushing and SIADH can be caused by small cell
- hypercalcemia of malignancy caused by squamous cell
Paraneoplastic syndromes:
Ectopic ADH releasing tumor type?
Small cell lung cancer
*causes SIADH
- cushing and SIADH can be caused by small cell
- hypercalcemia of malignancy caused by squamous cell
Paraneoplastic syndromes:
Ectopic PTHrP releasing tumor type?
Squamous cell lung carcinoma
- hypercalcemia of malignancy caused by squamous cell
- cushing and SIADH can be caused by small cell
Typical presentation of a gonadotroph pituitary adenoma?
Mass effect
*minimal secretion, “silent” or “null cell” adenoma
Diagnosis?
HA, N/V, papilledema,
Bilateral temporal hemianopsia
Under production of all pituitary hormones except prolactin
Pituitary lesion mass effect
*caused by neoplasm or hemorrhage
What transcription factor is elevated in most pituitary adenomas? (somato-, lacto-, thyro-)
PIT-1 transcription factor
*less clinically useful because it does not narrow it down very much
What transcription factor is elevated in corticotroph pituitary adenomas? (cushings disease)
TPIT transcription factor
*more useful because it is specific for corticotroph adenomas
What SOMATIC mutation is associated with somatotroph pituitary adenomas?
GNAS mutation
Somatic GNAS mutation pathophysiology in development of pituitary somatotroph adenoma?
- GNAS mutation = loss of function in Gs-a GTPase (part of GH receptor),
- Leads to increased GTP (cant break it down)
- Uninhibited cAMP driven somatotroph proliferation
What SOMATIC mutation is associated with corticotroph pituitary adenomas?
USP8 mutation
*leads to EGFR upregulation
What GERMLINE mutation is associated with somatotroph pituitary adenomas?
AIP (FIPA)
Other pituitary neoplasms:
Cystic mass lined with ciliated columnar epithelium
Can cause mass effect and/or rupture (pituitary inflammation and meningitis)
Rathke’s cleft cyst
Other pituitary neoplasms:
Cyst lined with squamous epithelium,
Calcified cyst
Wet keratin
Presents with growth retardation or hypopituitarism
Craniopharyngeoma
*kid form (adamantinomatous)
Other pituitary neoplasms:
Cyst lined with squamous epithelium,
Papillary structure
Presents with increased ICP or hypopituitarism
Craniopharyngeoma
*adult form (papillary)
Infarct and death of the pituitary due to disrption of the diaphragma sella,
CSF leak into the sella that compresses the pituitary
Primary empty sella syndrome
Expansion of the pituitary leading to infarction and death, leaving empty space in sella
Secondary empty sella syndrome
Diagnosis?
New mom presents with lactational dysfunction (hypopituitarism) and empty space in sella on imaging
Sheehan syndrome
*postpartum necrosis of anterior pituitary (secondary empty sella syndrome: pituitary expands in pregnancy leading to infarct and death of pit)
