Pituitary tumors Flashcards
What is the % of pituitary tumors in relation to all primary brain tumors?
∼10%–15% of all diagnosed primary brain tumors are of pituitary origin with up to 25% seen on autopsy series
What % of pituitary tumors are functional vs. nonfunctional?
75% of pituitary tumors are functional, while 25% are nonfunctional.
What are the sex and age predilection for pituitary tumors with symptomatic presentations?
Symptomatic pituitary tumors occur mostly in females. 70% occur from 30–50 yrs
What is a heritable syndrome that predispose to pituitary tumors, and what is the inheritance pattern?
MEN-1 (3 “Ps”: pituitary, parathyroid, pancreas), 11q13 mutant/menin. Autosomal dominant inheritance
What is Nelson syndrome?
Nelson syndrome is ACTH-secreting adenoma that develops after adrenalectomy (pts can develop hyperpigmentation of the skin d/t a melanocyte-stimulating hormone). These may be less responsive to RT.
What are the embryonic derivatives of the ant pituitary vs. post pituitary?
Anterior: Rathke pouch (oral ectoderm)
Posterior: extension of the 3rd ventricle (neuroectoderm)
What is the name for the bony structure that houses the pituitary?
The sella turcica houses the pituitary.
What are the boundaries of the sella?
Tuberculum sellae anteriorly, dorsum sellae posteriorly, sphenoid sinus inferiorly, dural folds superiorly, and post clinoid processes laterally.
What CN deficit is most commonly caused by pituitary adenoma?
CN II. Pituitary adenomas are the most common cause of optic chiasm compression. Less commonly, CN III, CN IV, and CN VI deficits can cause ocular motility Sx.
What hormones are secreted by lobes of the pituitary?
Anterior: prolactin (PL), GH, ACTH, TSH, LH, FSH
Intermediate: melanocyte-stimulating hormone (MSH)
Posterior: ADH, oxytocin
What is the histopathologic description of the cells of nonfunctional tumors?
Histopathologically, the cells of nonfunctional tumors are chromophobic.
What hormones are secreted by basophilic cells? Acidophilic cells?
Basophilic: ACTH, TSH, LH, FSH
Acidophilic: GH, PL
What is the most common functional pituitary tumor? 2nd most common?
3rd most common?
Prolactinoma (30%) > GH (25%) > ACTH (∼15%)
Which pituitary tumors are more common in males and the elderly? Which are more common in females?
Males and the elderly: nonfunctioning or GH
Females: PL and ACTH secreting
Which are the more common pituitary tumors: micro- or macroadenomas?
Macroadenomas (≥1 cm) are the more common pituitary tumors.
Which are the most common pituitary tumors in females?
Microadenomas (<1 cm) are the most common pituitary tumors in females, particularly those that are PL secreting.
What is the most common cause of pituitary dysfunction in adults? Children?
Adults: pituitary adenoma
Children: craniopharyngioma
What histologic features are prominent in prolactinomas?
Calcifications and amyloid deposits are prominent in prolactinomas.
What immunohistochemical stains are positive in pituitary adenomas?
Synaptophysin, chromogranin, and hormone-specific stains
With what signs/Sx do pts with nonsecretory pituitary tumors present?
Bitemporal hemianopsia (optic chiasm compression), HA (↑ ICP), oculomotor deficits: CNs III–IV, VI, V1–V2 (cavernous sinus compression), hydrocephalus (3rd ventricle compression), hyperprolactinemia (disruption of PL suppression from hypothalamus d/t compression of pituitary stalk), or panhypopituitarism (from general glandular disruption).
With what signs/Sx do pts with secretory pituitary tumors present?
Bitemporal hemianopsia (optic chiasm compression), HA (↑ ICP), oculomotor deficits: CNs III–IV, VI, V1–V2 (cavernous sinus compression), hydrocephalus (3rd ventricle compression), hyperprolactinemia (disruption of PL suppression from hypothalamus d/t compression of pituitary stalk), or panhypopituitarism (from general glandular disruption).
With what signs/Sx do pts with secretory pituitary tumors present?
PL secreting (50%): galactorrhea, amenorrhea, infertility, and vaginal dryness for women, loss of libido, erectile dysfunction and infertility for men GH secreting (25%): acromegaly ACTH secreting (20%): Cushing Dz TSH secreting (≤1%): hyperthyroid Sx
What is the DDx of a pt with a pituitary mass?
Pituitary tumor, craniopharyngioma, meningioma, glioma, suprasellar germ cell, mets, and benign lesions (cyst, aneurysm, empty sella syndrome)
What is the workup of a pt with a pituitary tumor?
Pituitary tumor workup: H&P (physical: CNs, visual field, endocrinopathy), labs, including hormone levels, thin-slice MRI through the base of skull, and tissue Dx (transsphenoidal resection)