Paraneoplastic syndromes in daily clinical practice

Paraneoplastic syndromes consist of disorders that accompany benign and malignant tumours, but are not directly related to mass effects or invasion by the primary tumour or its metastases. The pathophysiology of mostly paraneoplastic syndromes is not well known. The usual mechanism of their development is the aberrant production of substances (protein hormones, hormone precursors or hormone-like substances) by tumour tissue or autoimmune disorder. The neurological paraneoplastic syndromes are autoimmune disorders that can affect almost any part of the nervous system. The endocrine paraneoplastic syndromes are often certain clinical syndromes like paraneoplastic hypercalcaemia or the aberrant production of hormones by cancers. Many haematologic conditions, including anaemia, leucocytosis, thrombocytopenia or thrombocytosis, coagulapathy have been reported in association with cancer. Also paraneoplastic rheumatic syndromes have been reported in association of cancer. Skin can be involved in cancer in different ways: by metastases, as a part of a genetic disorder with a cutaneous component in which there is an inherited predisposition to the later development of malignancy, as a part of an acquired syndrome due to the toxicity of a carcinogen that induces malignant change and accompanying skin changes, as a consequence of immunosuppression, or by the development of specific lesions that occur as a paraneoplastic syndromes The most frequently diagnosed dermatologic conditions include acrokeratosis paraneoplastica, Sweet’s syndrome and paraneoplastic pemphigus. The purpose of this article is to describe the most popular in internal clinical practice neurologic, endocrine, haematologic, rheumatologic and dermatologic paraneoplastic syndromes associated with cancer.