This is true difficult case especially based a few photos. Differential diagnosis includes benign mucocele-like lesion and mucinous carcinoma.

Focal cystic wall lined with benign looking epithelial cells with associated myoepithelial cells, hemosiderin-macrophages (suggestive rupture of the cysts), detached clusters of epithelium within the mucin (often present in mucinous carcinoma, but they have benign looking in this case). Basically my feeling is that this is  mucocele-like benign lesion. However I cannot make the diagnosis only based on the above photos in true case. I have to read all true glass slides with microscopy for diagnosis.

So above just for your reference.

要排除粘液癌

粘液腺癌?好病例,学习了!