We present a challenging clinical case of an antisynthetase syndrome (ASS) with a four-year follow-up. The disease debuted with skin manifestations and interstitial lung disease (ILD), then the severe Raynaud's phenomenon came to the fore with the development of occlusive vasculopathy and critical digital ischemia. After the relief of vascular lesions, the severity of the condition was determined by ILD. The use of combined pulse therapy with cyclophosphamide and methylprednisolone, treatment with intravenous immunoglobulin made it possible to reduce the activity of ASS: lung lesion and the progression of vasculopathy. However, after the termination of an unplanned pregnancy, the patient again experienced an exacerbation with ILD progression. It was decided to use rituximab, against which the patient's condition was stabilized. Clinical and laboratory remission was achieved, which was maintained for a year and a half. However, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic triggered a re-exacerbation of the pulmonary domain of the disease, which forced us to use a nintedanib with a positive clinical and instrumental effect.

Vasculitis is a clinically diverse group of diseases with histopathological signs of blood vessel inflammation, which contributes to vascular damage and ischemic damage to the affected tissues. Vasculitic neuropathy is a common complication of the primary systemic vasculitides, such as polyartertis nodosa and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, systemic diseases of the connective tissue - systemic lupus erythematosus and Sjogren syndrome, vasculitis associated with infection, most often viral hepatitis C and B and non - systemic vasculitis neuropathy. Vessels of medium and small caliber are involved in the pathological process in these diseases. With all vasculitis, except for those caused by the direct effect of the infectious trigger on the blood vessel walls, the main pathogenetic mechanism is an autoimmune process with the development of vasa nervorum vasculitis - small arteries and vessels that supply peripheral nerves, and the outcome - nerve ischemia. The classic clinical presentation is an acute or subacute painful multifocal neuropathy that has a predilection for the lower extremities, affects two or more named nerves, and progresses in a step wise manner. However, vasculitic neuropathy can manifest in a variety of ways, including asymmetric polyneuropathies and distal symmetric sensory neuropathies, and it also can be slowly progressive, particularly in cases of nonsystemic vasculitic neuropathy (NSVN), a form of vasculitis that clinically remains restricted to peripheral nerves. Nerve biopsy can help establish the diagnosis of a systemic vasculitis, particularly when other organ involvement is not clinically apparent, and is required for diagnosis of NSVN. Neuropathy due to systemic vasculitis should be treated in accordance with the recommendations for the treatment of the underlying disease. In NSVH, the main medicine of choice are glucocrticoids, and in severe/progressive cases, pulse therapy with cyclophosphamide.

Aim: To study the nature of different variants of paraneoplastic syndrome (PNPS) in lung cancer, taking into account the features of the tumorous process and the complications of radiochemotherapy. Patients and Methods: We performed an analysis of the data of 1,669 patients with lung cancer aged between 24 and 87 years, among whom there were 89% of men and 11% of women. The ratio of small cell and non-small-cell histological variants of the lung cancer was 1: 4, IB, IIA, IIB, IIIA, IIIB and IV stages of cancer — 1:2:6:58:43:57. Results: PNPS developed in 16% of the lung cancer patients, in these patients we have detected a marked increase in the disease incidence in women, the peripheral form of the tumor, the apical variant of Pancoast — Tobias and adenocarcinoma, but no cases of the median lower localization of the tumor. The number of the upper lobar pathology was decreased, while the severity of the cancer was significantly greater, which more often occurred with exudative pleurisy, germination of the tumor into the chest wall and compression of the upper vena cava. The 21 components of PNPS pathology were established. We distributed them conditionally into the musculoskeletal system lesions, variants of skin vasculitis and autoimmune processes, the nature of which depended on the localization and course of the tumorous process, its histological variation and severity of the course. Moreover, PNPS negatively affected the development of radiochemotherapy complications and worsened survival rate. Conclusions: The course of PNPS in lung cancer is highly diverse, being a risk factor for a severe tumorous process that worsens the survival of patients