Pituitary Pathology Flashcards
What is the most common cause of hyperpituitarism?
Pituitary Adenomas
What is special about Atypical Adenomas?
They are more likely to be aggressive
Uniform, monomorphic sheets/cords of cells with an absence of reticulin
Pituitary Adenoma
What mutation is associated with Pituitary Adenomas?
GNAS –> inhibition of GPCR –> continual activation of hormone synthesis
Sx’s = amenorrhea, galactorrhea, loss of libido, infertility
Prolactinemia (commonly Lactotroph Adenoma)
What type of adenoma can cause gigantism and acromegaly?
Somatotroph Adenoma
What hepatic product is released due to a Somatotroph Adenoma?
IGF-1
What pituitary hormone is released due to a Somatotroph Adenoma?
GH
Sx’s = Increased body size with disproportionately long arms and legs, some signs of acromegaly in children
Gigantism
Sx’s = Enlarged jaw, feet, and hands, sausage-like fingers, thyroid, liver, heart, and adrenal issues
Acromegaly
What are some other findings due to GH oversecretion?
DM/Glucose intolerance
HTN
Muscle weakness
Gonadal dysfunction
How would you Dx a Somatotroph Adenoma?
Elevated serum GH/IGF-1 + failure to suppress GH after oral glucose load
What hormones does a Mammosomatotroph Adenoma secrete?
GH and PRL
What hormone does a Corticotroph Adenoma secrete and what is the net effect?
ACTH –> increased cortisol secretion –> hypercotisolism
What disease is due to excess ACTH secretion by a tumor?
Cushing Syndrome
What disease is due to excess ACTH secretion by the pituitary?
Cushing Disease
Corticotroph Adenomas will stain + for which things?
PAS, POMC
Sx’s = Buffalo hump, round face, stretch marks, ab weight gain, easy bruising, hirsutism
Excessive ACTH/Cortisol secretion
What is Nelson Syndrome?
Excessive cortisol secretion with no inhibitory effect due to Corticotroph Microadenoma present and surgical removal of the adrenal glands
How does excess ACTH lead to hyperpigmentation?
ACTH is a precursor molecule for melanocytes
What type of pituitary adenoma typically doesn’t cause any clinical Sx’s?
Gonadotroph Adenoma
How doo Gonadotroph Adenomas typically cause Sx’s and what are those Sx’s?
Mass effect
Sx’s = impaired vision, HA, diplopia, pituitary apoplexy
Define Plurihormonal Adenomas
They elaborate more than one hormone
Are aggressive
How do non-functioning Pituitary Adenomas typically present?
Mass effect Sx’s
How are Pituitary Carcinomas Dx?
By the presence of metastases
What are the most common hormones secreted from Pituitary Carcinomas?
ACTH, PRL
What is the most common cause of hypopituitarism?
Destruction of the anterior pituitary
What is Sheehan syndrome?
Postpartum necrosis of the anterior pituitary
What is the most common cause of ischemic necrosis of the anterior pituitary?
Sheehan syndrome
What is Primary Empty Sella syndrome?
A defect in the diaphragma sella –> arachnoid mater/CSF herniating into sella –> expansion of sella –> compression of pituitary
In what type of people does Primary Empty Sella syndrome typically occur?
Obese women with a history of multiple pregnancies
What are the most common presenting Sx’s of Primary Empty Sella syndrome?
Visual field defects
Hyperprolactinemia
Other endocrine abnormalities
Which hormone causes pallor due to loss of stimulatory effects on melanocytes?
MSH
Decreased ADH secretion due to a pituitary issue…
Central DI
Decreased ADH activity due to renal inability to find hormone…
Nephrogenic DI
Sx’s = excessive urination with low specific gravity, increased serum Na/Osmolality, thirst and polydipsia, dehydration
DI
Sx’s = hyponatremia, cerebral edema, neurologic dysfunction
SIADH
What are the most common causes of SIADH?
ADH secreting neoplasm (small cell carcinoma of lung)
Drugs increasing ADH secretion
CNS disorders
What tumors arise from remnants of the Rathke pouch?
Craniopharyngiomas
What are the main presenting Sx’s of Craniopharyngiomas?
HA
Visual disturbances
What is the morphology of Craniopharyngiomas?
Cystic and multilobulated with a capsule
Morphology = Calcified, nests/cords of squamous epithelium with peripheral palisading and lamellar keratin
Adamantinomatous Craniopharyngioma
Cysts containing cholesterol-rich, thick brown-yellow (machine-oil) fluid
Adamantinomatous Craniopharyngioma
What age group do Adamantinomatous Craniopharygiomas affect?
Children
Morphology = Solid sheets of papillae lined by well-differentiated squamous epithelium and NO calcifications, keratin, or cysts
Papillary Craniopharyngioma
What age group do Papillary Craniopharyngiomas affect?
Adults
What is the prognosis for Papillary Craniopharyngiomas?
Excellent, malignancy is very rare
