Figure 1.

Cecum mixed adenoneuroendocrine carcinoma consists of proliferation of two components. First component is represented by glandular structures with mucinous foci (A-B) and displays positivity for keratin 20 (C) without immunoreactivity for synaptophysin (D), with a high Ki67 index (E) and cytoplasmic expression of maspin (F); The second component is represented by solid tumor islands (G) that are negative for keratin 20 (H) and are immunoreactive for synaptophysin (I), with a lower Ki67 index (J) and slightly cytoplasmic expression of maspin (K).