Collision Tumor of the Thyroid Gland: Primary Squamous Cell and Papillary Thyroid Carcinoma
Figure 1
(a) Histological examination shows two distinct areas, one with islands of squamous cells in various stages of differentiation, intercellular bridges, and small keratin pearls (black dotted arrows) and the other with papillae lined by cuboidal cells with overlapping nuclei and finely dispersed optically clear chromatin (black thick arrows), (Hematoxyllin and Eosin X200). (b) The tumor shows positive nuclear stain for TTF-1 in papillary area.
