Positron Emission Tomography with Computed Tomography (PET/CT) is a nuclear medicine imaging modality using positron-emitting radiotracers and a combined PET and CT scanner in order to detect and localize high radiotracer signal abnormalities. Although PET has evolved into a diagnostic modality of prime importance in oncology (with the radiotracer (F18-FDG) it was originally envisioned to image and diagnose diseases of the brain and the heart. Lack or limited experience in PET may result in an erroneous interpretation of the findings in this sensitive imaging modality. The existence of various rare cancers has resulted in scanty if not a lack of knowledge about the usefulness of PET in these interesting albeit uncommon maladies. The author, drawing from more than ten years of experience as the chairman/director of the only PET Center in the Philippines, aims to present the most interesting cases he has encountered which may be educational to those beginning their practice or even helpful to veterans of the field whose scope of practice has been limited to the most common and reimbursable indications of an FDG-PET scan.