Deep learning has emerged as a transformative tool in medical diagnostics, particularly in the fields of radiology and histopathology. This study presents a comparative analysis of three prominent deep learning architectures: Convolutional Neural Networks (CNNs), Transformers, and hybrid models that combine the strengths of both. We explore the computational methods employed in each architecture, emphasizing their technical novelties, such as the use of attention mechanisms in Transformers and the integration of feature extraction and contextual learning in hybrid models.