<prompt> True about anaplastic thyroid carcinoma:Common in elderlyWell encapsulatedWill not invade surrounding structuresAll  <response>: Ans is A Common in elderly About option e Schwaz 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. 