Cancer甲状腺癌课件.pptVIP

Thyroid Cancer Thyroid Cancer Accounts for 1.5% of all cancers in the US Most common endocrine malignancy (95%) 22,000 cases per year and estimated 500 – 1000 patients die annually 90% of thyroid cancer cases have favorable prognosis Classification Incidence of Thyroid Cancer Follicular cell origin Differentiated Papillary 80% Follicular 10% Hurthle cell 3-5% Undifferentiated Anaplastic 1-2% Parafollicular cell origin – Medullary 5% Papillary Carcinoma Accounts for 90% radiation induced cancer Classified as microcarcinoma, intrathyroidal, and extrathyroidal Histologic variants: tall-cell, clear-cell, columnar, diffuse sclerosing Multicentric in 30-50% of tumors Spreads via lymphatics with propensity for mid- and lower-anterior cervical chain (Level VI) 20-50% patients have involvement of cervical LN Follicular Carcinoma Only 10% of thyroid cancers in developed countries, although more prevalent in regions with iodine deficiency Diagnosis depends on demonstration of vascular or capsular invasion Classified as minimally or widely invasive Vascular invasion tends to have a more aggressive course than capsular invasion Uncommon to have multicentric disease Hematogenous spread Follicular Carcinoma Where does follicular carcinoma tend to metastasize? Bone Lung Hurthle Cell Carcinoma High propensity to spread to cervical lymph nodes and high incidence of distant metastasis Less than 10% of Hurthle cell carcinomas take up radioiodine High tumor recurrence rate High mortality rate – 30% mortality at 10 years Anaplastic Carcinoma Increasingly rare Arise within differentiated cancers Pts 60 years old with rapidly expanding neck mass Local invasion very common at time of dx (FNA) Surgery plays limited role given advanced stage at dx Radiation and chemotherapy have not demonstrated any significant improvement in survival Median survival ~ 4 - 6 months Medullary Thyroid Carcinoma Originates from the parafollicular C cells Elevation in calcitonin