Clinical diagnostic imaging modalities of breast cancer are still having certain limitations such as low sensitivity in dense breast in mammography and low specificity of the B-mode ultrasound [1, 2]. Photoacoustic (PA) imaging has been introduced as an enabling tool to acquire important functional information of the pathologic tissues as well as molecular imaging of cancer when it is augmented with nano-sized contrast agents [3]. US tomography (UST) has shown superior utility imaging of the breast and is growing as reliable tool for characterizing breast lesions [4, 5]. In this study, we demonstrate the development of an US and PA tomography (USPAT) system, consists of a full-ring US acquisition and an all-reflective, aberration-independent, and easy to implement light delivery to achieve an omni-directional co-planar ring illumination.