Digitized TCGA pathology images can be found in the Genomic Data Commons — GDC Legacy Archive. GDC is the official source of TCGA genomic, clinical and molecular data.
Please note that where The Cancer Imaging Archive's collections reads:
Matched TCGA patient identifiers allow researchers to explore the TCGA/TCIA databases for correlations between tissue genotype, radiological phenotype and patient outcomes.
this means that patient identifier is matched across the GDC website (slides, genotype, clinical information) and TCIA (radiological imaging, clinical data) NOT case/control matching. Only patient data were included.
If you have downloaded radiology data of some TCGA subjects and want to access the pathology images, you'll need to follow the following steps