Ossicle/Oncology

THYROID DISEASE
Medullary Thyroid Carcinoma produces calcitoninAmyloid and leukocytic infiltrate on path Associated with RET-protooncogene and MEN IIa and IIb   Thyroid Binding Globulin Increases with estrogens, BCP's, pregnanacyDecreases with androgens High TBG = High T4, Low T3RU (T3RU inversely proportional to # unoccupied T3 binding sites) High T3RU with hyperthyroidism, alternate ligands - salicylate, clofibrate Low T3RU with hypothyroidism, increased TBG

T1 + T1 => T2, PLUS ADD'L T2 => T4 => T3 + T1<ul><ul> <li>T4 => T3 blocked in periphery by propylthiouracil <li>Tyr => Iodotyrosine blocked by thiouracil <li>T3 much more active than T4, half life 30h <li>T4 less active, half life 7 days <li>Serum T4 = Bound + Free (free T4 is active)</ul></ul>

Hypothyroidism - Low T4, Low T3RU Hyperthyroidism - High T4, High T3RU Grave's Ophthalmopathy - decompress orbits into ethmoids and maxillary sinus

Thyroiditis<ul><ul> <li>Acute Suppurative - (rare), hi WBC, nl ESR; Staph, Strep, Pneumococcus <li>Subacute (DeQuervan's) - (common), Decr T3RU, High T3 & T4; Rx steroids, ASA <li>Fibrous (Reidel's) - (rare), Rx debulking, steroids, cyclophosphamide <li>Chronic Lymphocytic (Hashimoto's) - (common), α-microsomal and α-TBG antibodies; Rx: thyroxine <li>Chronic non-suppurative - (rare) </ul></ul>