Fig. 3
From: Colorectal cancer metastases in thyroid: case report and literature review
Cytopathology and immunohistochemical staining of fine needle aspiration (FNA) sample from thyroid nodule. Cytopathology showed malignant features consistent with a metastatic adenocarcinoma of gastrointestinal origin, favouring a colorectal primary. Magnification is 400x. A ThinPrep with Papanicolaou stain shows clusters of malignant columnar cells forming glands with nuclear pleomorphism and hyperchromasia. Background “dirty necrosis” is evident. B Hematoxylin and eosin stained cell block sections show malignant columnar cells in glandular formations and background necrosis. C Immunohistochemical stain for CK-20 shows positive cytoplasmic staining. D Immunohistochemical stain for CDX-2 shows positive nuclear staining