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What is True about anaplastic thyroid carcinoma:a) Common in elderlyb) Well encapsulatedc) Will not invade surrounding structuresd) Distant metastasis commone) Some degree of differentiation to Papillary and Follicular types seen and explain in detail?
About option 'e' Schwartz writes:
"On gross inspection, anaplastic tumors are firm and whitish in appearance. Microscopically, sheets of cells with marked heterogeneity are seen. Cells may be spindle-shaped, polygonal, or large, multinucleated cells. Foci of more differentiated thyroid tumors, either follicular or papillary, may be seen, suggesting that anaplastic tumors arise from more well-differentiated tumors."