• CN III, IV, and VI
• ICA and ECA
• cavernous sinuses
• optic chiasm

• continuation of dura
• function
  • covers roof of sella turcica
  • protects pituitary from pressure of CSF in subarachnoid space

• nests of secretory cells
  • acidophil cells (syn. peptide hormones)
  • basophil cells (syn. glycoprotein hormones)
  • chromophobe cells (too few granules to be IDed as either acidophil or basophil)

• formed by invagination of Rathke's pouch in roof of oral cavity
  • occasionally see cystic remnants of this invagination
  • lined by squamous epithelium
  • tumors can often resemble normal structures of oral cavity
  • ectopic pituitary tissues may be found anywhere along migratory path

• clinical presentation
  • hormonal overproduction (most frequently of PRL, but less of GH, ACTH)
  • in men, initial presentation may be due to mass effects of hyperpituitary function
  • in women, nonfunctional tumors are relatively uncommon
• dx- image studies
  • if microadenoma, MRI used
  • if macroadenboma, plain films

• gross
  • spherical masses that grow by compressing adjacent pituitary
  • may protrude through diaphragma sellae (suprasellar extension)
  • may see erosion into and through bone with extension into adjacent sinuses
  • may be macroadenomas or microadenomas
• histology
  • uniform, but pleomorphism may be present
  • cant make dx of malignancy based on histology exam
• classification
  • size (micro and macro)
  • older schemes may be acidophil, basophil, or chromophobe cells (chromophobe is MAJORITY)
  • hormones present in tumor cells (ex: prolactinemias)

• prognosis
  • usually slow growing neoplasms
  • course is prolonged even though tumor has extended beyond the pituitary
• tx
  • for prolactinemia, dopamine agonists (decrease PRL production and reduce size of tumor)
  • if you stop tx, most patients will experience regrowth
  • if secretes GH, ACT or is nonfunctiona, we do surgery, radiation preferred for tumor in combo with medical therapy
    • for ACTH, cyproheptadine
    • for GH, somatostatin analogues

• epidemiology
  • mostly in children (arises from embryonic structure) but may be found in any age range
  • less common than adenomas
• origin- benign tumor derived from Rathke's pouch
• clinical presentation
  • suprasellar, midline location (but can be within sella or sinuses)
  • usually detected due to mass symptoms or pituitary hypofunction
• morphology
  • gross- cystic mass composed of structures normally found in oral cavity (squamous epithelium, mass of mineralized material simulating tooth buds)
    • may see calcification on X ray films
  • histologically bening
• tx is difficult
  • cause fatalities because it is difficult to remove entirely due to location
  • if the keratin in the cysts leak out, it can cause fatal chemical meningitis

• clinical presentation
  • hypotension
  • shock
  • pituitary is enlarged and more vascular than normal
    • ex: pregnancy or pituitary adenoma
• if there is a pregnancy related hemorrhage, it can lead to hypofunction called Sheehan's syndrome
• if pituitary adenomas lead to infarction and hemorrhage, its called pituitary apoplexy
  • leads to increase in CSF pressure, followed by coma and death

• pathogenesis
  1. there is a defect in the diaphragma sellae
  2. arachnoid is pushed into the sella by the pressure of the CSF
  3. causes selllar enlargement and compression of pituitary around periphery of sella
• epidemiology
  • usually middle aged women
  • very common cause of sella enlargement
• common clinical presentation
  • most are asymptomatic
  • most common symptoms due to increase PRL due to compression of pituitary stalk
• dx- usually incidental finding during imaging studies or autopsy

Although name says empty, there is usually a normal amount of pituitary tissue surroundin the fluid filled subarachnoid space that produces an empty appearance

• due to mass efffect
• due to hormone overproduction
• due to hormome underproduction

• headache
  • look for change in type, frequency, or duration of headaches compared to person's usual headaches
• vision problems due to compression of optic nerve and/or nerves supplying extra-ocular muscle (all of which pass near sella turcica) present in many patients
  • classic: bitemporal hemianopsia
  • most patients tend to have asymmetric visual field loss

• if overprod. gonadotropins, we see hypogonadism
  • pulsatile release is needed for normal function of gonads
• usually due to excess (in desc. order) of
  • PRL
  • GH
  • ACTH

• women- fairly dramatic
  • abnormal milk production (galactorrhea)
  • amenorrhea (remember PRL inhibits gonadotropin production)
  • usually, the above two symptoms co-exist
    • lack of normal dev. of follicles can lead to infertility
• men- majority are asymptomatic
  • impotence and infertility are most common complaints

• medications (MOST COMMON)
  • OCP's
  • phenothiazines
  • cimetidine
• pituitary adenoma
  • pituitary stalk compress base of brain (ex: craniopharyngioma, empty sella syndrome)

• gigantism (in childhood)
  • increase bone length and thickness
• acromegaly (in adulthood)
  • increase bone thickness (esp. in face)
    • prognathism (protruding lower jaw)
    • big digits (growth in hands, feet)

• symptoms
  • skin- thickening of soft tissue and overgrowth of sebaceous glands
    • thick, oily skin
  • heart- HTN, interstital fibrosis lead to cardiac damage
  • DM (GH antagonizes insulin)
  • degenerative arthritis (larger bones)
• dx
  • measure IGF-1 aka somatomedin-C
    • produced in response to GH
    • unline GH, there is no diurinal fluctuation

• common with pituitary tumors and infarct of tumors to have more than one hormone have some degree of underproduction
• usually the first one to be underproduced in GH (NO symptoms in adults)
• PRL underproduction
  • absent milk production in post partum pituitary infarction (otherwise asymptomatic)
• gonadotropin underpoduction
  • often asymptomatic in men
  • in women between 10 and 45, you will see cessation of menstrual cycles
• thyrotropin (takes more time to have underpoduction)
  • often presenting symptom in post-menopausal women and men
• ACTH and ADH underpoduction happens VERY LATE

• presentation (MOST common underproduced hormone)
  • short stature in kids (look like toddlers)
  • if severe, you will see hypoglycemia
• dx- lack of response of GH to normal stimuli
  • IGF-I not useful measurement in children under 5
• tx- GH (prompt increase in height and the earlier the tx, the greater the height that can be reached)

• most common isolated pituitary deficiency in adults
• presentation
  • lesion usually in hypothalmus, but can also be in pituitary or the stalk
  • polydypsia, polyuria (1 L/hr)
  • as long as patients have access to water, their plasma volume remains normal (thirst receptors still in tact)
  • when deprived of water, they become dehydrated (they cant concentrate their urine)
• common etiologies
  • tumors
  • any space occupying lesions
  • trauma to head
• prognosis- half of patients with post traumatic DI recover