Fig. 6

Histopathological findings of the recurrent lesion. A Hematoxylin and eosin staining findings. On the left side of the image, the recurrent tumor shows papillary proliferation that resembles the finding shown in Fig. 5A. Mucus production was observed in the atypical epithelial cells, as with the primary lesion. On the right side of the image, the tumor is expanding beyond the mucosa. B The tumor with a papillary structure was almost MUC1-negative; however, the tumor that exhibited invasion was MUC1-positive. C, D The tumor was MUC2-negative and MUC5AC-positive