Cytopathologic diagnosis of fine needle aspiration biopsies of thyroid nodules

Figure 1 Follicular cells arranged in a flat sheet, colloid and pigment-laden macrophages (× 40 pap stain on ThinPrep slide) (diagnostic categories II).

Figure 2 Crowded macrofollicles with mild irregularities in nuclear membrane and prominent nucleoli in a specimen with scant colloid (× 40 pap stain on ThinPrep slide) (diagnostic categories III).

Figure 3 A cellular specimen composed of Hürthle cells arranged in loosely cohesive sheets or isolated in a case diagnosed as Hürthle cell adenoma (× 40 pap stain on ThinPrep slide) (diagnostic categories IV).

Figure 4 Presence of cell group with nuclear crowding, increased nuclear-cytoplasmic ratio, irregularities in nuclear membrane and micro-nuclei (× 40 pap stain on ThinPrep slide) (diagnostic categories V).

Figure 5 Flat sheets showing enlarged, pale nuclei with finely granular chromatin of a papillary Ca case (× 40 pap stain on ThinPrep slide) (diagnostic categories VI).

Figure 6 Enlarged follicular cells arranged in monolayer sheets and follicular groups with nuclear elongation and chromatin clearing in a follicular variant of PTC case (× 40 pap stain on ThinPrep slide) (diagnostic categories VI).

Figure 7 Tumor cells with distinct granules with eccentric nuclei. The nuclear chromatin appears as “salt and pepper type” in a medullary carcinoma case (× 40 pap stain on ThinPrep slide) (diagnostic categories VI).