The article reports the problems of rheumatic disease as paraneoplastic syndrome. It includes the description of the clinical case of axial spondyloarthritis as paraneoplastic syndrome related to the neuroendocrine tumor of the duodenum. In this case, axial spondyloarthritis was characterized by rapid involvement of peripheral and axial symptoms, high acute phase reactants, resistance to drug therapy and reduction of clinical and laboratory symptoms after treatment for neuroendocrine tumor. In differential diagnostics of and paraneoplastic rheumatic disease, it is necessary to pay attention for the time of occurrence of rheumatic symptoms, clinical symptoms before and after surgical and non-surgical treatment for cancer, response to drug therapy, family cancer anamnesis, exposure to carcinogens, previous immunosuppressive therapy, as well as severity of general constitutional symptoms, atypical manifestations of rheumatic disease, age of disease debut over 50 years.