Paraneoplastic Syndromes (PNS) are a group of disorders that cause endocrinologic, hematologic, neurologic, and dermatologic manifestations of cancer. These conditions are not directly caused by tumour metastasis, but rather the malignancies produce hormones and other proteins which act to disrupt the body's homeostasis, thereby causing symptoms. The neurological complications of PNS are the result of an immune response to tumour antigens. PNS have been associated with a variety of cancers, such as genitourinary, ovarian, and breast, but are most commonly associated with neuroendocrine tumours. These syndromes can even occur before the primary tumour is identified. Historically, these conditions were considered rare, but given the difficulties with diagnosis, the exact prevalence is unknown. This book focuses on the symptoms, diagnosis, and treatment of PNS. More specifically, it discusses current concepts in common PNS; cutaneous PNS and skin features of internal malignancy; PNS in patients with malignancies of the genitourinary tract; PNS polyneuropathies; the correction of cancer-related anemai with oxyresveratrol; and PNS associated with lung cancer.