Ossicle/Oncology

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Head and Neck Oncologic Surgery[edit]

THYROID DISEASE[edit]

Medullary Thyroid Carcinoma produces calcitonin

  • Amyloid and leukocytic infiltrate on path
  • Associated with RET-protooncogene and MEN IIa and IIb


Thyroid Binding Globulin

  • Increases with estrogens, BCP's, pregnanacy
  • Decreases 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

  • T4 => T3 blocked in periphery by propylthiouracil
  • Tyr => Iodotyrosine blocked by thiouracil
  • T3 much more active than T4, half life 30h
  • T4 less active, half life 7 days
  • Serum T4 = Bound + Free (free T4 is active)


Hypothyroidism - Low T4, Low T3RU

Hyperthyroidism - High T4, High T3RU

Grave's Ophthalmopathy - decompress orbits into ethmoids and maxillary sinus

Thyroiditis

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