Path: Pituitary & Sellar Flashcards
What are the basics of the posterior pituitary?
mostly axons
nuclei are pituicytes
makes ADH & oxytocin - supraoptic
What are the major hypothalamic nuclei that send factors into the portal system?
arcuate nucleus
paraventricular nucleus
supraoptic nucleus
What gene is involved in many patients with pituitary adenomas?
MEN-1 (except null cell)
but most are still sporadic
How do women with prolactin producing adenomas present as opposed to men?
women - earlier and with micro
men - macro and higher serum prolactin
What is the histology of prolactin secreting adenomas?
adenoma w sheet-like architecture
sparsely granulated > densely granulated
sometimes amyloid deposits
What are signs and symptoms of GH producing adenomas?
mass effects - inc hydrocephalus if gets into 3rd ventricle
excess GH/IGF-1 - gigantism or acromegaly
peripheral arthropathy
LV hypertrophy
sometimes diabetes
What are the different classifications of GH secreting adenomas?
entirely somatotrophs - only produce GH
individual cells produce GH and prolactin = mammosomatotroph
cells either produce one or other = mixed GH-prolactin adenomas
What is the histology of GH producing adenomas?
sparsely or densely granulated - granules have the GH
fibrous bodies = collections of keratin filaments
What is a “silent” ACTH adenoma?
adenoma that expresses ACTH on immunohistochemistry but shows no clinical or biological signs of hypercortisolism
may be more aggressive
What are null cell adenomas?
composed of differentiating adenohypophyseal cells, but usually no immunohistochemical demo of hormone production
rarely express FSH or LH
What are the signs and symptoms of null cell adenoma?
usually none of excess hormone, except stalk effect
large at presentation and mass effects
What is the gross appearance of null cell adenoma?
soft and yellow-tan
may have cysts w hemorrhagic or clear fluid
What is the prognosis of null cell adenoma?
if total resection - small recurrence rate at 5 yrs
but b/c so big, rarely complete resection
What are signs and symptoms of pituitary apoplexy?
subarachnoid hemorrhage increased intracranial pressure headache visual symptoms worsened hypopituitarism
What are pituicytomas?
composed of cells differentiating as neurohypophyseal pituicytes = supporting glial cell of post pituitary
WHO grade 1
What is the histology of pituicytoma?
elongated, bipolar glial cells shaped like spindles
arranged in fascicles
What is a craniopharyngioma?`
squamous epithelial tumors - due to proliferation of cells associated w Rathke’s pouch
adamantinomatous (more common) and papillary variants
WHO grade 1
What is the population distribution of craniopharyngioma?
adamantinomatous: most kids 5-15 and adults 45-60
papillary: almost exclusively adults
What are signs and symptoms of craniopharyngioma?
visual disturbances
endocrine disturbances
diabetes
signs of elevated intracranial pressure if 3rd ventricle involved
What is the gross appearance of craniopharyngiomas?
well circumscribed
adamantinomatous - variegated w cystic areas, fibrotic areas and areas of calcification
maybe dark, greenish-brown fluid
tumor cells may adhere to nearby vessels or invade
papillary do NOT have cysts or calcifications
What is the histology of craniopharyngiomas?
adamantinomatous - cells rest on loosely arranged connective tissue and surround cords or lobules of more well-differentiated squamous epithelial, nodules of keratin and cysts w squamous debris
papillary - well-differentiated squamous epithelial cells, no basaloid layer of keratin
What is pilocytic astrocytoma?
slow growing, mostly in kids and young adults, well circumbscribed, WHO grade 1
Where do pilocytic astrocytomas occur?
throughout CNS - mainly sellar area and cerebellum
What are signs and symptoms of pilocytic astrocytomas?
focal neurologic deficits or non-localizing due to mass effect (inc hydrocephalus)
cerebellar - headache, nausea, vomiting, clumsiness
thalamic - hemiparesis
What is the appearance of pilocytic astrocytomas?
well-circumscribed and contrast enhancing
often cystic
soft and gray or tan and cystic grossly
What is the histology of pilocytic astrocytomas?
hair like cytoplasmic processes
biphasic architecture (layered areas of bipolar astrocytes next to loosely packed areas of stellate astrocytes w shorter cytoplasmic processes)
some cells have rosenthal fibers
brightly eosinophilic, cigar or corkscrew shaped proteinaceous masses = eosinophilic granular bodies
What are the genetic associations of pilocytic astrocytomas?
NF1 (neurofibromatosis type 1) - loss of ch 17q
What is the prognosis of craniopharyngioma?
key factor in recurrence is extent of resection: tumors >5 cm have worse prognosis
What are Rathke’s cleft cysts?
usually between ant and post
sometimes >1 cm and extend from sella to suprasellar region = symptomatic
What are the signs and symptoms of Rathke’s cleft cysts?
visual and endocrine disturbances
diabetes
What is the histology of rathke’s cysts?
single layer of cuboidal or columnar cells on thin layer of collagenous connective tissue
sometimes goblet cells, sometimes ciliated
produce and surround watery to mucoid material
What are the features of lymphocytic hypophysitis?
firm grossly
infiltrated by B and T lymphocytes, plasma cells, and histiocytes
sometimes follicles w germinal centers
Abs in tissue to pituitary tissue and sometimes individual pituitary hormones
What are germ cell tumors in the sellar region?
similar to tumors in gonads
5 types - most common in sella is germinoma
usually midline in sellar or pineal regions
