<prompt> A well differentiated follicular carcinoma of thyroid can be best differentiated from a follicular adenoma byHuhle cell changeLining of tall columnar and cuboidal cellsVascular invasionNuclear features  <response>: A well differentiated follicular carcinoma of thyroid can be best differentiated from a follicular adenoma by capsular invasion vascular invasion. This is not made out in FNAC and hence FNAC is not very useful. USG can make out this differentiating feature of follicular carcinoma. Reference : page 482 SRBs manual of surgery 5th edition 