SM148 Pathology/Histology Flashcards
What are pituicytes, where are they found?
Specialized glial cells that support axons in the posterior pituitary
What are Herring bodies, where are they found?
Neurosecretory vesicles in the posterior pituitary
What is the major blood supply of the anterior pituitary lobe? What is at risk for?
Low-pressure portal venous circulation from hypothalamus. Low pressure, so vulnerable to ischemia.
What is the major blood supply of the posterior pituitary lobe?
Direct branches of hypophyseal arteries.
Development of the anterior and posterior pituitary lobes?
Anterior is an ectodermal pocket (Rathke’s pouch) that extends from the oral cavity. Posterior is a depression of the hypothalamic floor (neuroectoderm). Anterior grows up and posterior grows down and they fuse.
What is the most common cause of hyperpituitarism?
Pituitary adenomas.
Morphological features of pituitary adenomas?
Monomorphous cytoplasm (cells all look the same, no nests). Low mitotic activity. Loss of reticulin network.
How are pituitary adenomas categorized? What is the most common variant?
By the type of hormone that is secreted. Prolactin-producing adenomas are the most common.
Clinical signs of prolactinoma? Pathology?
Clinical: amenorrhea/galactorrhea in females, impotence and loss of libido in males. Path: can be micro or macro, calcification (pituitary stones), stalk effect (compression of pituitary stalk).
Clinical signs of GH-producing adenoma? Pathology?
Clinical: gigantism and acromegaly. Path: most are macro. Densely-granulated (strong pink staining) or sparsely-granulated (fibrous bodies). Elevated IGF-1.
Clinical signs of ACTH-producing ademona? Pathology?
Clinical: Cushing’s disease, Nelson syndrome (enlargement of ACTH adenoma after removal of adrenal glands). Path: most are micro. Basophilic, densely-granulated, strong PAS and ACTH-reactive.
Clinical signs of non-functioning pituitary adenoma? Pathology?
Clinical: mass effect/hypopituitarism. Path: most macro. Synaptophysin and chromogranin positive, hormone markers negative.
Where are craniopharyngiomas derived from? Path findings?
Most common childhood supratentorial tumor. Derived from remnants of Rathke’s pouch (squamous differentiation). Suprasellar, “wet keratin,” calcifications, cholesterol crystals. T
Lymphocytic hypophysitis characteristics?
Common during pregnancy or postpartum period. Autoimmune. Both cellular and humoral components. Symmetric enlargement of pituitary with anterior insufficiency.
CNS sarcoidosis characteristics?
Affects suprasellar region. Non-caseating granulomas with multinucleated giant cells.
