华氏巨球蛋白血症 (WM) 是伴有骨髓受累和血清 IgM 副蛋白的淋巴浆细胞淋巴瘤的主要亚型，是一种通常与肾实质受累相关的血液病。然而，淋巴瘤浸润肾脏的抗中性粒细胞胞浆抗体（ANCA）阴性寡免疫新月体肾炎（PICGN）非常罕见，迄今为止英文文献中仅描述了两例慢性淋巴细胞白血病病例。我们在此报告了第一例发生 ANCA 阴性 PICGN 的 WM 患者。患者为76岁男性，因血清球蛋白升高、双侧腹股沟淋巴结肿大，经骨髓及腹股沟淋巴结病理检查确诊为WM。一个月后，他被查出患有急性肾损伤和蛋白尿。肾活检证实存在 WM 伴 PICGN 实质受累； ANCA 检测呈阴性。他接受了甲基泼尼松龙脉冲治疗，随后口服泼尼松龙。此外，还给予静脉注射利妥昔单抗和口服环磷酰胺六个疗程。他的肾脏和血液状况都有显着改善。该病例的临床病程提示 ANCA 阴性 PICGN 可能代表一种副肿瘤综合征，也是 WM 相关肾脏病变的罕见表现。早期肾活检和及时治疗可以改善患者的预后。© 2024 亚太肾病学会。

Waldenstrom macroglobulinaemia (WM), the predominant subtype of lymphoplasmacytic lymphoma with bone marrow involvement and serum IgM paraprotein, is a haematological condition commonly associated with renal parenchymal involvement. However, antineutrophil cytoplasmic antibody (ANCA)-negative pauci-immune crescentic glomerulonephritis (PICGN) in kidney infiltrated by lymphoma is very rare, with only two cases described in chronic lymphocytic leukaemia in English literature so far. We herein report the first patient with WM developing ANCA-negative PICGN. He was a 76-year-old male who presented with elevated serum globulin level and bilateral groin lymph node enlargement, subsequently diagnosed to have WM after pathologic examination of the bone marrow and groin lymph node. One month later, he was found to have acute kidney injury and proteinuria. Renal biopsy confirmed the presence of parenchymal involvement by WM accompanied by PICGN; while ANCA testing was negative. He was treated with pulse methylprednisolone followed by oral prednisolone. In addition, six courses of intravenous rituximab and oral cyclophosphamide were given. There was significant improvement in both his renal and haematological conditions. The clinical course of this case suggested that ANCA-negative PICGN may represent a paraneoplastic syndrome and a rare manifestation of WM-associated renal lesion. Early kidney biopsy and prompt treatment may improve the outcome of patients.© 2024 Asian Pacific Society of Nephrology.