Atypical Features Resembling Poorly Differentiated Thyroid Carcinoma Presenting Entirely within a Follicular Adenoma

Figure 3

(A) Low power view of PDTC-like focus and adjacent trabecular region that does not fulfil PDTC criteria; (B) PDTC-like focus and adjacent trabecular region showing higher MIB-1 proliferation index; (C) all areas showing retained of TTF1; (D) PDTC-like focus showing loss of thyroglobulin expression and trabecular region with reduced expression.

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