Fig. 2

Histopathology and cytology of BC-PDMs and corresponding PTT. H&E staining of BC-PDMs and corresponding primary, (A) invasive ductal breast carcinomas (NST) with/without ductal in-situ (DCIS) lesions and (B) invasive lobular breast carcinomas (ILC) with/without lobular in-situ (LCIS) lesions. (C) Pathological evaluation of BC-PDMs. n = 39/40 BC-PDMs resembled histopathology of breast carcinomas, n = 36/38 of the corresponding primary tumor histotype (NST/ILC; NST/ILC histology not available for one sample; one other sample classified as medullary carcinoma and excluded from comparison of NST and ILC BC-PDMs) and n = 23/40 BC-PDMs displayed stromal parts. Histopathological tumor characteristics of BC-PDMs were assessed such as hyperchromasia and nuclei differentiation (nuclear grade 1: nuclei with little variation in size and shape; grade 3: large nuclei with high variation in size and shape; grade 2: nuclei show features between 1 and 3. (D) Movat-pentachrome staining revealed connective tissue compartments in BC-PDMs and PTT e.g. collagen fibers (yellow), PGs/GAGs (cyan blue), collagen/PGs/GAGs-superimposition (green), mucins (blue) and elastin (black; representative images shown for n = 8 matched pairs of BC-PDMs and corresponding PTT). (E) Amount of collagen fibers within BC-PTT and BC-PDMs. Collagen fibers are measured semi-quantitatively as %-area fraction. RGB images were unmixed by subtractive mixing (color deconvolution) via ImageJ. (F) Averaged %-area fraction of BC-PTT and BC-PDM (n = 17) samples shown in (E). Data are mean with SEM. *p < 0.05, **p < 0.01, ***p < 0.001. Unpaired, parametric t-test. Scale bars BC-PDMs: 50 µm/10 µm (zoom); PTT: 500 µm/50 µm (zoom; paired sections of BC-PDMs and corresponding PTT specimen were available from n = 17 samples displaying stromal parts for Movat-pentachrome stainings)