Pituitary Tumors Note

Two lobes in the pituitary

anterior lobe and posterior lobe

anterior lobe physiology

glandular part, glandular cells secrete 7 hormones (GH, PRL, TSH, FSH, LH, MSH, ACTH)

posterior lobe physiology

produces oxytocin (smooth muscle contraction) and antidiuretic hormone (water resorption)

why is it important to address pituitary adenomas

hormones are affected and will present issues

epidemiology & etiology

benign, functioning vs non functioning, before puberty not later adulthood

pituitary critical structures/OARs

optic chiasm, optic nerve, cavernous sinuses, brain tissue, brainstem

pituitary anatomy

lies on sella turcica (sphenoid), attached to hypothalamus. behind TMJ

pituitary adenomas are classified according to

size, growth pattern

2 size classifications of pituitary adenomas

microadenoma (<10mm) and macroadenoma (>10mm)

intrahypophyseal

stays within pituitary

intrasellar lesions

grow within confines of sella turcica

diffuse adenomas

fill entire sella and erode wall

invasive neoplasms

rapid growth rate, erode outside sella & invade tissue

histopathology pituitary

sinusoidal, papillary, diffuse

functioning pituitary adenoma

tumors retain hormone producing capabilities, pt will have to be supplemented w/ hormones they need

nonfunctioning pituitary adenoma

go beyond sella turcica and cause pressure on surrounding structures, HEADACHE

signs and symptoms

headache, altered visual activity, blindness, cranial nerve defects

detection & diagnosis

CT, MRI, PET

treatment options

surgery, EBRT

EBRT

chin tucked, SRS IMRT 3D or photon, vertex field, collimator to get off eye

radiation issues

hypopituitarism, visual defects, stroke, brain tumor

prognosis

surgery curative, RT 90%, good tumor control rate