Rare tumors (RT) are an increasing problem in oncology. The main characteristic of RT is the low frequency of the event, that determines difficult and sometimes late diagnosis and a great uncertainty in diagnosis and treatment. The aim of this book is to offer a little help in spreading the knowledge of low-incidence tumors in oncology, in order to alert the nonexpert clinician to take them into consideration, and to show the most accredited and updated medical treatment for some of the rare oncologic diseases. This booklet is not conclusive, but we hope to give help in prescribing treatments for the main RT, underlining the need of a multidisciplinary approach in these tumors, as well as cooperation with the centers of expertise. For the sake of brevity and competence, only solid RT are included; for the lymphoproliferative or hematologic low-incidence diseases we refer to hematologists. Each chapter provides brief information about the epidemiology of and clinical aspects for every RT; and, following each chemotherapy schedule, we report a short description of the hematologic toxicities related to the treatment.