Quiz 3 Flashcards
(205 cards)
Hormones released by the anterior pituitary gland:
- thyroid-stimulating hormone (TSH)
- prolactin (PRL)
- adrenocorticotropin hormone (ACTH)
- growth hormone (GH)
- follicle-stimulating hormone (FSH)
- luteinizing hormone (LH)
In pituitary histology, the pink staining acidophils (eosinophilic cytoplasm) release ______ and ______. The purple staining basophils secrete __________, ___________, __________, and ________.
Pink: * GH * PRL Purple: * FSH * LH * TSH * ACTH
Histologically, the posterior pituitary resembles _______ tissue.
Neural
- glial cells
- nerve fibers
- nerve endings
- intra-axonal neurosecretory granules
The 2 hormones secreted by the posterior pituitary, ______ and _______, are synthesized __________.
ADH and oxytocin
in the hypothalamus, stored in the post pit
__________ occurs as a result of excess secretion of trophic pituitary hormones.
Causes include:
Hyperpituitarism
- pituitary adenoma (MC)
- hyperplasia
- carcinomas of ant pit
- secretion or hormones by non-pit tumors
- certain hypothalamic d/o’s
Result of deficiency in one or more of the hormones produced by the pituitary gland:
Hypopituitarism
- ischemic injury
- surgery
- radiation
- inflammatory reactions
- non-functioning adenoma
Pituitary-related changes that may be referred to as mass effect:
- sellar expansion
- bony erosion
- disruption of the sella
Pituitary lesions of a sufficient size often compress:
leading to:
the optic nerve at the optic chiasm
visual field abnormalities, usu lateral visual field deficits
“bitemporal hemianopsia”
MC pituitary tumor:
Pituitary adenoma
Also MC brain tumor!
15% of all intracranial lesions
How do you differentiate a macro- and microadenoma?
Macro - >/=10mm
Micro -
How are pituitary adenomas classified?
By hormone secreted (MC - PRL)
formerly by staining, still use “chromophobic” for non-fxn tumors
Describe the typical pituitary adenoma (gross):
soft
well-circumscribed
mb confined to sella, or extend superiorly
larger:
erode sella
infiltrate neighboring tissues (cavernous/sphenoid sinuses, dura)
Histology of pituitary adenoma:
- small round cells
- uniformly round nuclei
- pink to blue cytoplasm
- nest or cords
- prominent vascularity
Mass effect sx:
- HA
- visual field deficit
- cranial nerve defect
- cavernous sinus syndrome (rare)
- sx specific to excess hormone (if fxn)
MC functioning pituitary adenoma:
prolactinoma (lactroph adenoma)
30%
underlies ~25% of cases of amenorrhea
Adenomas of the anterior pituitary are a (major/minor) clinical feature of ______, a form of inherited endocrine disorder.
major
multiple endocrine neoplasia type 1 (MEN 1 )
MEN causes various combos of benign or malignant tumors in endocrine glands or may cause glands to enlarge w/o forming tumors
MEN syndromes MC affect:
- parathyroid glands
- pancreatic islet cells
- anterior pituitary (25% of MEN1)
MEN1 may cause non-endocrine tumors likes:
- facial angiofibromas
- collagenomas
- lipomas
- meningiomas
- ependymomas
- leiomyomas
Acute hemorrhage into an adenoma or pituitary infarction:
pituitary apoplexy - rapid enlargement of the lesion
80% not previously dx - although usu pre-existing
MC initial sx of pituitary apoplexy:
sudden HA
- often w/rapidly worsening visual field defect
- double vision
Necrosis of the pituitary gland due to blood loss and hypovolemic shock during and after childbirth:
Sheehan’s syndrome (postpartum hypopituitarism)
Hypertrophy and hyperplasia of lactotrophs (PRL cells) during pregnancy results in:
enlargement of the anterior pituitary, without a corresponding increase in blood supply.
agalactorrhea - MC initial sx
may go undetected, mb found later upon hypothyroid or 2° adrenal insufficiency dx
An empty sella contains:
only CSF w/o visible pituitary tissue on MRI
pituitary stalk typically visible, extends to floor of sella
Hypothalamic suprasellar tumors may induce:
hypo- or hyperfunction of the anterior pituitary, diabetes insipidus, or combinations of these manifestations.