Case Report: Mixed ductal–lobular carcinoma consisting of invasive lobular carcinoma with a glycogen-rich clear cell pattern and elevated tumor mutation burden

In this case, the gILC and IDC components of an MDL shared a common origin, but exhibited marked genomic divergence. This experience also shows that SETD2 functional impairment may underlie gILC hypermutation, while HNF1B overexpression could contributes to a glycogen-rich clear cytoplasm. Overall, this case emphasizes the complexity of MDL with gILC, and highlights the need for further studies to clarify the underlying molecular mechanisms and their prognostic implications.