分析抗中性粒细胞胞浆抗体(ANCA)相关性血管炎(AAV)合并小细胞肺癌的临床症状、影像学表现、病理学特征，提高对该病的认识。

回顾性分析1例经实验室指标及病理学证实的AAV合并小细胞肺癌患者的临床、实验室检验及影像学资料并文献复习。

AAV合并小细胞肺癌患者临床表现为发热、咳嗽、咳痰，抗感染治疗效果差，实验室结果：髓过氧化物酶、pANCA阳性；尿常规：红细胞2＋；cANCA、抗肾小球基底膜抗体定性、抗蛋白酶3抗体、抗心磷脂抗体IgG、抗心磷脂抗体IgM、癌胚抗原、神经特异性烯醇化酶、抗核抗体均阴性；患者胸部增强CT：左肺下叶占位并纵隔多发肿大淋巴结，周围型肺癌可考虑，建议进一步检查除外炎性病变；双肺间质性改变。

对于患者肺内表现为肺间质改变和肺内实变影，反复应用抗生素症状未见好转，应该完善血管炎筛查，并积极明确肺内病变病理，需考虑血管炎合并肺癌的可能，避免漏诊、误诊的发生。

To enhance the recognition of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) combined with small cell lung cancer by analyzing the clinical symptoms, imaging features, pathological features.

The clinical status, serum biochemical and computed tomography (CT) data of ANCA-associated vasculitis combined with small cell lung cancer confirmed by serum biochemical and pathology were analyzed retrospectively, and relevant literatures were reviewed.

Clinical manifestations of ANCA-associated vasculitis with small cell lung cancer were fever, cough, sputum, effect of anti-infection treatment was poor, laboratory results: myeloperoxidase, pANCA were positive; routine urine: 2+ of red blood cells; cANCA, glomerular basement membrane antibody qualitative resistance, anti-proteinase 3 antibodies, anti-cardiolipin antibody IgG, IgM, carcino-embryonic (CEA), neuron specific enolase (NSE), antinuclear antibodies were negative.Enhanced chest CT showed left lower lobe placeholder and multiple swollen lymph nodes in mediastinal; peripheral lung cancer might be considered.Double pulmonary interstitial changed.

For patients with pulmonary interstitial and pulmonary consolidation, the use of symptoms did not improve after repeated use of antibiotics, we should check the vasculitis screening and positively definite lung lesions in pathology, especially when therapy effect is poor.We should consider the possibility of AAV combined with lung cancer, avoiding the occurrence of missed diagnosis and misdiagnosis.