Successful Treatment of a Mixed Neuroendocrine-Nonneuroendocrine Neoplasm of the Colon with Metastases to the Thyroid Gland and Liver

Figure 2

Histopathological and immunohistochemical findings of the thyroid tumor following the thyroidectomy. (A) The tumor consists of two distinct areas: a small-cell carcinoma indicated by arrows and a large-cell carcinoma shown by arrow heads (H&E staining at low power). (B) Half of the tumor shows solid growth of small cells with round-to-oval nuclei and scant cytoplasm, consistent with small-cell carcinoma (H&E staining at high power). (C) The other half shows nests and rosettes of polygonal cells with enlarged round-to-oval and prominent nuclei, consistent with large-cell carcinoma (H&E staining at high power). (D) Immunohistochemistry revealed positive staining for synaptophysin in the overall tumor at low power.