The latest authoritative medical textbook published in the United States in 2010, Murray and Nadel Respiratory Medicine, may no longer have a chapter on “Wegener’s granulomatosis”. The textbook has officially renamed “Wegener’s granulomatosis” to “necrotizing granulomatosis (NGV)”. NGV is an autoimmune disease that mainly affects the upper respiratory tract, lungs and kidneys, but can also involve the ears, eyes, joints, muscles, skin, heart and nervous system, etc. The clinical manifestations are complex and varied, and the diagnosis depends mainly on clinical and pathological findings. Other immunosuppressive and biological agents also have a role. The clinical features of NGV are characterized by systemic necrotizing microangiitis and granuloma formation, which can affect all systems, most often the upper and lower respiratory tracts and the kidneys, with a variety of clinical manifestations. In a recent study, the rates of involvement of the upper respiratory tract, lower respiratory tract and kidney were 63.5%, 60.4% and 57.3%, respectively. Lungs: one of the most frequently involved organs with diverse clinical manifestations The common clinical manifestations of NGV involvement in the lungs are cough, chest pain, hemoptysis and dyspnea, and the chest imaging changes are complex and varied. The incidence of chest CT abnormalities is high, and our study showed that abnormalities were found in 92.1% of patients. Single or multiple nodules and masses in the lungs are the most common manifestations of NGV, and the size and number of nodules and masses increase as the disease progresses, and our study showed their incidence to be 76.3%, which is consistent with the literature incidence of 70%-80%. Necrotic cavities are one of the main manifestations of NGV. The cavities are irregular in shape and appear as thick-walled, thin-walled or circular cavities, with thick-walled cavities being the most common. Patchy shadows are also a common feature of NGV, and bronchial inflation signs are seen within the shadows, often with wandering changes, suggesting possible combined alveolar hemorrhage. Alveolar hemorrhage is often considered to be the initial clinical manifestation of NGV, with an incidence of approximately 5%. The feature of ground glass changes is also a common manifestation of the lesion, with pathology of alveolar hemorrhage, infiltration of necrotic cells within the alveoli, and fluid exudation secondary to small vessel vasculitis. When the hemorrhage occurs around a nodule, high-resolution CT shows a ground glass pattern surrounding the solid nodule, called the “halo sign. Studies have shown that nodules or masses, solid lung changes, or ground glass shadows suggest active lung disease in patients with NGV, while irregular pleural changes are more common in patients with previously active NGV. In addition, our study showed a 26.3% incidence of imaging abnormalities in asymptomatic patients, suggesting that chest CT should also be routinely performed in patients without pulmonary symptoms. Changes in lung function in NGV include restrictive and/or obstructive ventilatory impairment, with the most common change being reduced diffusion function. Patients with combined large airway or subglottic stenosis have pulmonary function manifested by abnormal flow rings. Other organs: NGV also frequently invades the heart and kidneys NGV often involves other organs (e.g., kidneys, heart). Oliveira reported that 31% of patients with NGV have cardiac lesions associated with the disease. common lesions include focal ventricular wall motion abnormalities, left ventricular enlargement, and pericardial effusion. patients with NGV have an increased incidence of deep vein thrombosis, with an annual incidence of 7.0% reported by Merkel et al, which is 7 times higher than in patients with SLE and 23 times higher than in the normal population. Our study showed a 48.3% incidence of cardiac ultrasound abnormalities, 4.2% incidence of venous thromboembolism, and 43.9% incidence of anemia in patients with NGV. A study of 23 patients with chronic renal failure found no significant correlation between anemia and abnormal renal function, which is consistent with the results of foreign studies, suggesting that factors other than renal insufficiency may play an important role in the cause of anemia in NGV patients. New advances in NGV diagnosis For patients with NGV, biopsies of upper and lower respiratory tract, lung, kidney and skin are an important basis for diagnosis. For asymptomatic patients, serological examination of ANCA and CT scans of sinuses and lungs are helpful for diagnosis. Diagnostic points: mainly rely on clinical and pathological findings The average time to diagnosis of Wegener’s granulomatosis is 5 to 15 months. Foreign data report that the time to diagnosis is 3 months in 40% of patients and up to 5 to 15 years in 10% of patients. For the most effective treatment, early diagnosis of NGV is crucial. In asymptomatic patients, serological examination of ANCA and CT of the sinuses and lungs can help in the diagnosis. Tissue biopsies of the upper and lower respiratory tract, lungs, kidneys, and skin are important for diagnosis, and pathology shows necrotizing granulomatous inflammation. Small to moderate caliber arterioles and a few capillaries have vasculitis and fibrinoid degeneration with neutrophil infiltration of the vessel wall. The kidneys often show granuloma formation, focal, segmental, crescentic necrotizing glomerulonephritis with no or little immunoglobulin as well as complement deposition by immunofluorescence. When diagnosis is difficult, thoracoscopy or open-chest biopsy may be performed to provide a pathologic basis for diagnosis. The most common pathologic manifestations of NGV include necrosis, granulomas, and/or vasculitis, but the probability of all three being present together is low, and some patients require repeated biopsies with a wide variation in the rate of positive biopsies from site to site. Current diagnostic criteria for NGV often use the 1990 American College of Rheumatology classification criteria (see table). Ancillary diagnosis: ANCA as a marker of NGV Laboratory tests in patients with NGV show elevated blood white blood cells (WBC), increased erythrocyte sedimentation rate (ESR), elevated C-reactive protein (CRP), and renal insufficiency. Recent studies have shown the importance of ANCA as a marker for the early diagnosis of ANCA-associated small vessel vasculitis, and the enzyme-linked immunosorbent assay (ELISA) with high-sensitivity protease 3-specific anti-neutrophil cytoplasmic antibody (PR3-ANCA) has a sensitivity of 98.5% and specificity of 96% for the diagnosis of NGV. Our study showed that PR3-ANCA positivity was 79.3% and myeloperoxidase-specific anti-neutrophil cytoplasmic antibody (MPO-ANCA) positivity was 12%. MPO-ANCA positivity was mainly seen in PR3-ANCA negative patients and ANCA titers could assess the degree of disease activity.