Path: Pituitary & Sellar

Question 1

What are the basics of the posterior pituitary?

Answer 1

mostly axons
nuclei are pituicytes
makes ADH & oxytocin - supraoptic

Question 2

What are the major hypothalamic nuclei that send factors into the portal system?

Answer 2

arcuate nucleus
paraventricular nucleus
supraoptic nucleus

Question 3

What gene is involved in many patients with pituitary adenomas?

Answer 3

MEN-1 (except null cell)

but most are still sporadic

Question 4

How do women with prolactin producing adenomas present as opposed to men?

Answer 4

women - earlier and with micro

men - macro and higher serum prolactin

Question 5

What is the histology of prolactin secreting adenomas?

Answer 5

adenoma w sheet-like architecture
sparsely granulated > densely granulated
sometimes amyloid deposits

Question 6

What are signs and symptoms of GH producing adenomas?

Answer 6

mass effects - inc hydrocephalus if gets into 3rd ventricle
excess GH/IGF-1 - gigantism or acromegaly
peripheral arthropathy
LV hypertrophy
sometimes diabetes

Question 7

What are the different classifications of GH secreting adenomas?

Answer 7

entirely somatotrophs - only produce GH
individual cells produce GH and prolactin = mammosomatotroph
cells either produce one or other = mixed GH-prolactin adenomas

Question 8

What is the histology of GH producing adenomas?

Answer 8

sparsely or densely granulated - granules have the GH

fibrous bodies = collections of keratin filaments

Question 9

What is a “silent” ACTH adenoma?

Answer 9

adenoma that expresses ACTH on immunohistochemistry but shows no clinical or biological signs of hypercortisolism
may be more aggressive

Question 10

What are null cell adenomas?

Answer 10

composed of differentiating adenohypophyseal cells, but usually no immunohistochemical demo of hormone production
rarely express FSH or LH

Question 11

What are the signs and symptoms of null cell adenoma?

Answer 11

usually none of excess hormone, except stalk effect

large at presentation and mass effects

Question 12

What is the gross appearance of null cell adenoma?

Answer 12

soft and yellow-tan

may have cysts w hemorrhagic or clear fluid

Question 13

What is the prognosis of null cell adenoma?

Answer 13

if total resection - small recurrence rate at 5 yrs

but b/c so big, rarely complete resection

Question 14

What are signs and symptoms of pituitary apoplexy?

Answer 14

subarachnoid hemorrhage
increased intracranial pressure
headache
visual symptoms 
worsened hypopituitarism

Question 15

What are pituicytomas?

Answer 15

composed of cells differentiating as neurohypophyseal pituicytes = supporting glial cell of post pituitary
WHO grade 1

Question 16

What is the histology of pituicytoma?

Answer 16

elongated, bipolar glial cells shaped like spindles

arranged in fascicles

Question 17

What is a craniopharyngioma?`

Answer 17

squamous epithelial tumors - due to proliferation of cells associated w Rathke’s pouch
adamantinomatous (more common) and papillary variants
WHO grade 1

Question 18

What is the population distribution of craniopharyngioma?

Answer 18

adamantinomatous: most kids 5-15 and adults 45-60
papillary: almost exclusively adults

Question 19

What are signs and symptoms of craniopharyngioma?

Answer 19

visual disturbances
endocrine disturbances
diabetes
signs of elevated intracranial pressure if 3rd ventricle involved

Question 20

What is the gross appearance of craniopharyngiomas?

Answer 20

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

Question 21

What is the histology of craniopharyngiomas?

Answer 21

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

Question 22

What is pilocytic astrocytoma?

Answer 22

slow growing, mostly in kids and young adults, well circumbscribed, WHO grade 1

Question 23

Where do pilocytic astrocytomas occur?

Answer 23

throughout CNS - mainly sellar area and cerebellum

Question 24

What are signs and symptoms of pilocytic astrocytomas?

Answer 24

focal neurologic deficits or non-localizing due to mass effect (inc hydrocephalus)
cerebellar - headache, nausea, vomiting, clumsiness
thalamic - hemiparesis

Question 25

What is the appearance of pilocytic astrocytomas?

Answer 25

well-circumscribed and contrast enhancing
often cystic
soft and gray or tan and cystic grossly

Question 26

What is the histology of pilocytic astrocytomas?

Answer 26

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

Question 27

What are the genetic associations of pilocytic astrocytomas?

Answer 27

NF1 (neurofibromatosis type 1) - loss of ch 17q

Question 28

What is the prognosis of craniopharyngioma?

Answer 28

key factor in recurrence is extent of resection: tumors >5 cm have worse prognosis

Question 29

What are Rathke’s cleft cysts?

Answer 29

usually between ant and post

sometimes >1 cm and extend from sella to suprasellar region = symptomatic

Question 30

What are the signs and symptoms of Rathke’s cleft cysts?

Answer 30

visual and endocrine disturbances

diabetes

Question 31

What is the histology of rathke’s cysts?

Answer 31

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

Question 32

What are the features of lymphocytic hypophysitis?

Answer 32

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

Question 33

What are germ cell tumors in the sellar region?

Answer 33

similar to tumors in gonads
5 types - most common in sella is germinoma
usually midline in sellar or pineal regions