Describe the general locations of cells within the "Adenohypothesis" aka Anterior pituitary.
Anterior Pituitary has cells that make LH, FSH, Prolactin, TSH, Growth hormone and ACTH in the following distribution (see picture):
ACTH and TSH are more midline as is the Posterior Pituitary
GH/PRL are more lateral flanks
What is the main clinical manifestation of the Neoplasms of the Pituitary?
Bitemporal Hemianopsia!!! Pituitary adneoma!!!
What do you see cellularly in the posterior pituitary? What is the funny name for these features and what's inside of them?
Terminal Axon Swellings (Boutons) filled w/ ADH and Oxytocin = Herring Bodies!
In general, describe what the histology of normal pituitary looks like compared to an adenoma - broad terms here.
Anterior Pituitary normally shows lots of colors bc clusters of cells making lots of different hormones
- Mixed Cells and Nested ARchitecture
Adenoma is more clonal and uniform and only 1 color!
- cytoplasmic uniformity and no nested cell architecture
What is the pathological effect of a Null-cell adenoma or one that is hypofunctioning?
MASS effect!!! and often it causes hypo-functioning of other pituitary cells bc of the mass effect
Micro vs Macro adenoma? Which cell types tend tobe smaller?
Macro-adenoma > 1 cm and Microadeboma < 1cm
ACTH producing tumors tend to be small/microadenomas that can invade cavernous sinus and cause hydrocephalus! Yikes!
What is the MOST COMMON functional tumor of the anterior pituitary? What does it secrete? How can you use the levels of this hormone to correlate to pathology? What is the exception?
Serum Prolactin correlates w/ Tumor Size:
- elevation proportional to tumor size
BUTTTTT if there can also be large tumor and only little Prolactin elevation = Stalk effect --> Compress stalk and stop release of normal inhibitory Da onto pituitary
- therefore wont respond to Bromocriptine!
Stalk Effect: (NON-Tumor) damage to stalk to stop inhibitory Da = mild hyper--prolactinemia
What are the clinical signs of a Prolactinoma?
Loss of libido
Describe the symptoms of Acromegaly?
Galactorrhea and sexual dysfunction - GH can co-produce Prolactin
Cardiomegaly and HTN
Face growing and bone growing stufffffffff
Sausage fingers hahaa
Abnormal Glucose Tolerance and Glucosuria! - Insulin resistance
What is the second most common functional neoplasm? What can it co-express? How do you treat it?
What does persistent hypersecretion lead to....
Somatotroph Adenoma - causes Acromegaly and Gigantism
Co-expression of Prolactin seen
Medical Tx - Octreotide
Persistent hypersecretion of GH stimulates hepatic secretion of IGF-1 leading to insulin resistance
Cushing's Disease - what's happening there? Disease vs Syndrome? Who gets it?
Cushing Disease - small tumor in sella causing pituitary hypersecretion of ACTH (vs syndrome which is non-pituitary source)
Females > Males
ACTH producing adenoma that leads to hyperplastic adrenals secondarily
What are the pathological findings for a Corticotroph adenoma?
Often small Microadenoma (< 1cm)
*Crooke's Hyaline Change - cells lose granules and gain cytokeratin filaments in cytoplasms of the non-neoplastic ACTH cells bc too much Cortisol causing negative feedback on them but not on the tumor cells
What are other functioning adenomas of the pituitary?
Gonadotroph Adenomas - LH/FSH present in middle aged people
- gonadotroph deficiency often paradoxically present bc adenoma destroying pituitary moreso than secreting
Thyrotroph Adenoma - 1% of all adenoma - rare cause of central hyperthyroidism
- high TSH levels in the face of High Thyroxin
What do you need to diagnose pituitary carcinoma?
Metastatic disease - very rare
How much pituiary has to be destroyed to see hypopituitarism? What are some causes of it?
75% destruction and causes include:
- Apoplexy - hemorrhage into an ademona (excruciating HA)
- Sickle Cell
- Elevatd Itracranial pressure
- Trauma and radiation
- Empty Sella Syndrome
- Rathke's Cleft Cyst!!!
What is empty sella syndrome?
Herniation of arachnoid tissue through defect in sellar diaphragm into sella
can expand and see empty sella bc looks devoid of contents but not really empty bc herniation of arachnoid in there
What is a "SupraSellar Tumor" ? Who gets them? What are the buzzwords for this? Subtypes?
Craniopharyngioma - 5% intracranial tumors
Kids and young people
Slow growing but difficult to resect:
- on imaging/grossly see Cystic w/ Calcifications
- Machinery Oil-like cyst fluid
- tooth remnants from walls of Rathkes cleft - tumors of mandible-like - Odontogenic Tumor
- Peripheral Palisading, Stellate, Wet Keratin
Subtypes: Adamantinomatous (more common) and Papillary
What are the 2 posterior Pituitary Syndromes we leanred about and how do you get them and how do they present? commee onnnnn.....easssyyyyy
1) Diabetes Insipidus - presents w/ polyuria, polydipsia, inability to concentrate urine, Hypernatremia
Causes include - Trauma (surgery), tumors, inflammatory disorders
2) Syndrome of Inappropriate ADH secretions - Hyponatremia, cerebral edema and neurologic dysfunction
Causes include - Small cell carcinoma/paraneoplastic, TB, Pneumonia, injury to hypothalamus