Endo memorization stuff

PIT1

• master switch shared by the cells that make prolactin, GH, and TSH

• (high levels of prolactin suppress GnRh in the hypothalamus)

TPIT

corticotroph cell type —> ACTH excess causing Cushing disease

SF1

• develops gonadotrophs (LH and FSH)

• most common silent PitNET

Thyroid cancers

papillary/follicular —> oncoytic —> poorly differentiated —> anaplastic

• moving along this spectrum, tumors lose thyroid-specific features

• also become more aggressive and accumulate more mutations

Papillary carcinoma

• BRAF V600E is the classic mutation

• spread through lymphatics (commonly goes to cervical lymph node)

• most common type of thyroid cancer

• generally excellent prognosis

Follicular carcinoma

• driver: RAS mutations (feed into growth-signaling pathways)

• spread: invade blood vessels, spread hematogenously to bone and lung

• rarely goes to lymph nodes

oncocytic carcinoma

• follicular-derived tumor

• cells are packed with abnormal mitochondria

• mitochondria DNA mutations and widespread chromosomal loses

• low RAI avidity, RAI therapy is less effective

poorly differentiated carcinoma

• high-grade follicular cell cancer (btwn differentiated and anaplastic)

• starts with RAS or BRAF mutation

• acquires additional hits, especially TERT and p53 mutations

• aggressive

• reduced iodine avidity

anaplastic carcinoma

• follicular cells that are undifferentiated

• genetics: BRAF, RAS, p53, TERT

• rapid, locally invasive growth

• most lethal human cancers

• fast-growing neck mass

• near-complete loss of follicular cell identity

• does not take up iodine

medullary carcinoma

• parafollicular C cells (neuroendocrine cells)

• RET mutations (germline in MEN2 or somatic)

• biomarkers: calcitonin and CEA

• doesn’t come from follicular cells —> doesn’t take up iodine, RAI is not useful

MEN1

• menin

• Parathyroid

• Pituitary

• Pancreatic

• neuroendocrine tumors

MEN2A

• RET

• medullary thyroid carcinoma

• pheochromocytoma

• parathyroid disease hyperplasia

MEN2B

• medullary thyroid carcinoma

• pheochromocytoma

• marfanoid habitus

MEN4

• rare MEN 1 -like tumor predisposition syndrome