甲狀腺髓質癌常見臨床症狀與治療建議.pdf

PAPILLARY CARCINOMA

• Most common thyroid malignancy: 65-60% of thyroid malignancies in adults, >90% in children
• Female predominance, mean age 40 yr
• Increased incidence in Hashimoto's thyroiditis or following radiation
• Clinical presentation: thyroid nodule (cold) in 67%, thyroid nodule and LN in 13%, LN only in 20%
• Size varies widely; may be quite small
• Solid, white, firm, often infiltrating; 10% show cystic change
• Well-developed branching, complex papillae with edematous or hyalinizedfibrovascular cores, ± lymphocytes, hemosiderin, some follicles (irregular to tubular)
• Nuclear features (may have some, none, all; focal or diffuse):
  • Ground glass (optically clear) nuclei, large, overlapping (note: often absent in frozen section/cytologic material)
  • Nuclear pseudoinclusions (cytoplasmic invaginations)
  • Nuclear grooves
• Mitoses rare; fibrosis common
• Psammoma bodies present in 30-50% of cases
• May see solid/trabecular pattern or squamous metaplasia (common; most common at periphery of lesion)
• Multifocal in 25-75% of cases; vascular invasion in 5%
• Immunoreactive for low and high molecular weight (MW) keratin (note: normal thyroid usually negative for high MW), thyroglobulin, EMA, vimentin, ±CEA
• Associated with RET oncogene and papillary thyroid carcinoma (PTC) oncogene
• SPREAD
  • Extrathyroid extension in 25%
  • Cervical LN involvement in ~50%; often cystic changes
  • Hematogenous spread less common than in other thyroid carcinomas
• PROGNOSIS
  • Poor prognosis: >40 yr old, male, extrathyroid extension, large tumor size, nonencapsulated, multicentricity, distant metastases, aneuploidy
  • Anaplastic foci develop in 1%; essentially all die
  • Not related to prognosis: relative amounts of papillae vs. follicles, history of irradiation, fibrosis, squamous metaplasia, positive cervical LNs