Vaginal cancer: Why should we care? Anatomy, staging and in-depth imaging-based review of vaginal malignancies focusing on MRI and PET/CT

Vaginal cancer often poses a challenge for clinical and radiological diagnosis, and its risk factors, progression, and treatment are still poorly established. Although vaginal malignancies are rare, even globally, their rates have increased due to the increased access to healthcare and the evolution of screening measures and diagnostic methods. Because the vaginal cavity is a virtual space, it can harbor lesions that often go unnoticed and, not infrequently, diagnosed belatedly. MRI and, more recently, PET/CT are part of the imaging armamentarium that have already been incorporated into the clinical staging and management of gynecological tumors, allowing excellent morphological characterization of the lesion, its topography and relationship with adjacent structures for the investigation of disease dissemination, overcoming limitations of clinical methods, such as speculum examination, usually restricted to observation only of the superficial characteristics of these lesions. Some vaginal neoplasms have characteristic MRI patterns, which, combined with expert knowledge of anatomy, allow identification of local macroscopic details (such as the mucosal, submucosal, and muscle layers). Furthermore, the application of PET/CT, already well established for identifying systemic disease, has a large impact on patient prognosis. The objective of this work is to review the epidemiological aspects of primary vaginal cancers and the imaging patterns of their main histological subtypes based on MRI and PET/CT, with a brief discussion of the local anatomy, oncological staging, and treatment.