Fig. 1

The morphologies of MPE-derived human breast cancer In Vitro models exhibited heterogeneous patterns. A Majority of cell lines grow as adherent form, suggesting cells floating in the pleural cavity maintained the capability to adhere. Various growth patterns include polygonal (n = 8), fibroblast-like (n = 1), round (n = 9), oval (n = 1) and mixed (n = 5) form. The names of cell lines are indicated upper-left corner. Multiply collected samples from the same patient are indicated with black squares. Scale bar = 200 μm. B Bright field images of three PDX-derived organoids displayed mostly spheroidal and asymmetric morphologies. Scale bar = 100 μm. C Immunocytochemistry of PDX-derived organoids and hematoxylin–eosin (H&E) staining of paraffin sections demonstrated organoids maintained the characteristics of the original breast tumor. Scale bar = 20 μm