Term
| Mutations involving _______ are probably the best-characterized molecular abnormalities in pituitary adenomas. |
|
Definition
|
|
Term
| The a-subunit of a G protein binds... |
|
Definition
|
|
Term
| What is GNAS? Mutations can cause what sort of problem? Which types of adenomas has this been associated with? |
|
Definition
| gene for G-protein alpha subunit, mutation can interfere with intrinsic GTPase activity and lead to constitutive activation and generation of cAMP. 40% of somatotroph adenomas have these mutations. Also seen in corticotroph adenomas. NOT seen in thyrotroph, lactotroph, or gonadotroph because they don't use cAMP-dependent pathways |
|
|
Term
| Are most pituitary adenomas sporadic or familial? |
|
Definition
| overwhelming majority are sporadic |
|
|
Term
| Name the 4 genes identified as a cause of familial pituitary adenomas. |
|
Definition
| MEN1, CDKN1B, PRKAR1A, AIP |
|
|
Term
| What is MEN1, and what do mutations cause? |
|
Definition
| Gene product is tumor suppressor menin, those with MEN1 syndrome get tumors in multiple endocrine organs including pituitary. Rare in sporadic cases of pituitary adenomas. |
|
|
Term
| The gene product is cell cycle checkpoint regulator p27 or KIP1, mutations are responsible for subset of pts with MEN1-like syndrome who lack MEN1 abnormalities. What is the gene? |
|
Definition
|
|
Term
|
Definition
| Auto-dom disorder, mutation of PRKAR1A, protein kinase A regulatory subunit 1A. Characterized by pituitary and other endocrine tumors. Gene encodes a tumor suppressor that regulates activity of protein kinase A, loss of it leads to inappropriate activation of cAMP cellular targets. |
|
|
Term
| Testing for ____ is typically recommended for CH adenomas arising in younger patients. |
|
Definition
|
|
Term
| Abnormalities in cyclin D1, p53, RB1 are associated with what consequence? Activating mutations of HRAS are observed in which conditions? |
|
Definition
| Aggressive tumors. Rare pituitary carcinomas. |
|
|
Term
| What distinguishes an invasive adenoma? This is seen in approx what percentage of cases? |
|
Definition
| tumor is not grossly encapsulated and infiltrates the neighboring tissues. Macroadenomas tend to be invasive more frequently. |
|
|
Term
| What accounts for the soft, gelatinous nature of most pituitary adenomas? What distinguishes it from the rest of the normal parenchyma? |
|
Definition
| Reticulin is sparse. Cellular monophorphism and sparse reticulin distinguish it. |
|
|
Term
| A subset of adenomas, classified as atypical adenomas, display which features? |
|
Definition
| brisk mitotic activity, staining of greater than 3% of nuclei with Ki-67 proliferation marker, extensive p53 immunoreactivity. They have higher propensity for aggressive behavior. |
|
|
Term
| What is the most frequent type of hyperfunctioning pituitary adenoma? |
|
Definition
|
|
Term
| Prolactinomas have a tendency to undergo what sort of process? |
|
Definition
| dystrophic calcification, from isolated psammoma bodies to extensive calcification - pituitary stone |
|
|
Term
| What causes amenorrhea, galactorrhea, loss of libido and infertility? |
|
Definition
|
|
Term
| What cause underlies almost 25% of cases of amenorrhea and is more readily diagnosed in women from 20-40? |
|
Definition
|
|
Term
| Prolactinemia can result from ________ hyperplasia, such as when there is an interference with normal ______. |
|
Definition
| lactotroph, dopamine inhibition of prolactin secretion. |
|
|
Term
| Any mass in the suprasellar compartment can disturb the normal inhibitory effect on... |
|
Definition
|
|
Term
| Densely granulated somatotroph adenomas have which features? What about sparsely granulated? Which one do bihormonal mammosomatotroph adenomas resemble? |
|
Definition
| monomorphic, acidophilic, strong cytoplasmic GH reactivity, cytokeratin staining in perinuclear distribution. Chromophobe cells, pleomorphism, weak focal staining for GH. Usually the densely granulated version. |
|
|
Term
| Describe what corticotroph adenomas tend to look like at the time of diagnosis. They have variable reactivity for which substances? |
|
Definition
| Usually small microadenomas, often basophilic or densely granulated, rarely chromophobic or sparsely granulated. POMC, ACTH, B-endorphin. |
|
|
Term
| A large destructive adenoma develops in patients after surgical removal of the adrenal glands for tx of Cushings syndrome. This pt has which syndrome? He would present with what sort of symptoms? Why might his skin look odd? |
|
Definition
| Nelson syndrome, mass effects (no hypercortisolism), hyperpigmentation |
|
|
Term
| How do unusual plurihormonal adenomas usually behave? |
|
Definition
|
|
Term
| Why can gonadotroph adenomas be difficult to recognize? |
|
Definition
| they secrete hormones inefficiently and variably, and do not usually cause a recognizable clinical syndrome |
|
|
Term
| Gonadotroph adenomas are associated with paradoxical.... |
|
Definition
| hypogonadism (decreased energy, libido, amennorhea) |
|
|
Term
| Demonstration of craniospinal or systemic mets is a sine qua non of a pituitary... |
|
Definition
|
|
Term
| Majority of pituitary carcinomas have what properties? |
|
Definition
| functional, secreting ACTH and prolactin most commonly |
|
|
Term
| Hypopituitarism accompanied by evidence of posterior pituitary dysfunction in the form of DI is almost always __________ in origin. |
|
Definition
|
|
Term
| If I had a structure lined by ciliated cuboidal epithelial cells with occasional goblet cells and anterior pituitary cells, that accumulated proteinaceous fluid and expanded, compromising the rest of my pituitary gland, what might I have? |
|
Definition
|
|
Term
| What syndrome involves a defect in the diaphragma sella that allows arachnoid mater and cerebrospinal fluid to herniate into the sella, classically occurring in obese women with a hx of multiple pregnancies? |
|
Definition
|
|
Term
| What is secondary empty sella? |
|
Definition
| A mass enlarges the sella, then it is surgically removed or undergoes spontaneous necrosis |
|
|
Term
| Mutation of POU1F1 leads to... |
|
Definition
| (pituitary-specific homeobox gene) combined pituitary hormone deficiency |
|
|
Term
| Gonadotropic deficiency leads to... |
|
Definition
| Amenorrhea and infertility in women. Decreased libido, impotence and loss of public and axillary hair in men. |
|
|
Term
| One of the most frequent causes of SIADH is ectopic secretion by... |
|
Definition
| malignant neoplasms, particularly SCC of lung |
|
|
Term
| Tumors in which region can cause hypo or hyperfunction of the anterior pituitary, DI or combinations? |
|
Definition
|
|
Term
| What are the most common suprasellar tumors? |
|
Definition
| fliomas and craniopharyngiomas |
|
|
Term
| What is the age distribution for craniopharyngiomas? Abnormalities of which signaling pathways have been reported? |
|
Definition
| bimodal - 5-15 and over 65. WNT signaling including B-catenin mutations |
|
|
Term
| Which type of tumor does this describe: Radiological demonstrable calcification, nests or cords of stratified squamous epithelium embedded in a spongy reticulum, palisading of the squamous epithelium in the periphery, compact lamellar "wet" keratin? |
|
Definition
| adamantinomatous craniopharyngioma |
|
|
Term
| What type of fluid is often found in adamantinomatous craniopharyngiomas? What extends into the adjacent brain? |
|
Definition
| cholesterol-rich, thick brown-yellow fluid compared to machine oil, extends fingerlets of epithelium into adjacent brain where they elicit a brisk glial reaction |
|
|
Term
| Papillary craniopharyngiomas lack which features? |
|
Definition
| keratin, calcification, cysts, peripheral palisading, spongy reticulum |
|
|
Term
| What is the prognosis of craniopharyngiomas? |
|
Definition
| generally great, recurrence-free. Larger are more invasive but this doesn't impact survival. Malignant transformation into squamous carcinomas is very rare, and usually occurs after radiation. |
|
|
