[Paraneoplastic syndromes: pathogenetic theories, clinical aspects and therapeutic approach].

Paraneoplastic syndromes are uncommon diseases with different pathogenesis and clinical manifestations, correlated with neoplasms but not due to the tumor, metastasis or other distant effects. The aim of the present article is to describe the main paraneoplastic syndromes (neurological, endocrine-metabolic, rheumatological, osteo-articular, dermatological, hematological, vascular and nephrological), the associated pathogenetic theories (theory of the common embryonal sketches, theory of reactivation of the information and autoimmune theory) and the most important therapeutic approaches, on the basis of the literature. Experimental works, reviews and clinical observations, in some cases still in progress, regarding the described syndromes, their pathogenesis and their therapeutic approach have been examined. No meta-analyses regarding paraneoplastic syndromes have been published in the literature. The better described pathogenesis is the autoimmune one, characteristic of neurological, nephrologic and some dermatologic syndromes, for which the clinical and laboratory findings have been well supported. The pathogenetic theories associated with the other syndromes have been correlated on the basis of the literature. Paraneoplastic syndromes are important because their identification permits an early diagnosis of tumors and rapid treatment, with a largely improved prognosis and life expectancy for the patient. They often represent the only signal of a silent neoplasm; sometimes they precede the tumor itself. More studies are necessary for a better definition of their clinical aspects and pathogenesis and to delineate standard guidelines for a diagnostic-therapeutic approach to these diseases.