Endocrine 1 Flashcards
By which four mechanisms can endocrine derangements stem from?
- Impaired hormone synthesis
- Impaired hormone release
- Abnormal hormone-target interaction
- Abnormal target response
What are the three general classifications of endocrine diseases?
- Overproduction
- Underproduction
- Diseases associated with the development of mass lesions
What is the most common cause of hyperpituitarism?
An adenoma of the anterior pituitary.
Describe two characteristics of anterior pituitary adenomas.
- Can be functional (causing symptoms related to excess hormone production) or silent (no symptoms related to excess hormones).
- Most are composed of a single cell type, making one hormone.
What is the most common adenoma of the anterior pituitary that secretes more than one hormone?
One that secretes both GH and prolactin
Name the associated hormone and syndrome with the cell type:
Lactotroph
Prolactin - causes amenorrhea or galactorrhea (milky nipple discharge not associated with pregnancy) in women. Causes hypotension and loss of libido in men.
Name the associated hormone and syndrome with the cell type:
Corticotroph
ACTH and other POMC-derived peptides - causes Cushing and/or Nelson syndrome
Name the associated hormone and syndrome with the cell type:
Gonadotroph
FSH, LH - causes menstrual disturbances in women and loss of libido in men
Name the associated hormone and syndrome with the cell type:
Somatotroph
GH - causes gigantism in prepupertal children and acromegaly in adults
Name the associated hormone and syndrome with the cell type:
Thyrotroph
TSH - causes hyperthyroidism
Name the associated hormone and syndrome with the cell type:
Mammosomatotroph (mixed adenoma)
GH and Prolactin - causes gigantism/acromegaly and amenorrhea and galactorrhea (women) and hypotension and libido loss in men.
Are “hormone negative adenomas” symptomatic?
Nope
What is the difference between a macroadenoma and microadenoma of the pituitary?
Macroadenomas are larger than 1 cm, microadenomas are smaller than 1 cm
Describe the morphology of a pituitary adenoma (3).
- Well-circumscribed and soft.
- May be confined by the sella turcica (a depression in the skull where the pituitary sits).
- Larger lesions extend superiorly through the sellar diaphragm into the suprasellar region and can compress the optic chiasm and adjacent structures.
____% of pituitary adenomas are invasive. Describe these.
30%. They are nonencapsulated and infiltrate adjacent bone, dura, and (uncommonly) the brain.
What is bitemporal hemianopsia and what can cause it? How does this disease cause bitemporal hemianopsia?
It is a type of partial blindness where vision is missing in the outer half of both the right and left visual fields. It can be caused by pituitary adenomas that extend into the suprasellar region and compress the optic chiasm.
Describe the microscopic changes seen in a pituitary adenoma (6).
- Composed of uniform polygonal cells arrayed in sheets, cords, or papillae.
- Sparse CT.
- Not much mitotic activity.
- Cytoplasmic staining is highly varied (acidophilic, basophilic, or chromophobic).
- Cellular monomorphism.
- Absence of a significant reticulin network.
Can the functional status of a pituitary adenoma be reliably predicted from the histologic appearance?
Nope
How do you distinguish a pituitary adenoma from non-neoplastic anterior pituitary parenchyma?
Cellular monomorphism and absence of reticulin network.
What is the most common type of hyperfunctioning pituitary adenoma (50% of cases)?
Prolactinoma