Ishida Taiki, Morita Ken, Masamoto Yosuke, Mizuno Hideaki, Taoka Kazuki, Abe Hiroyuki, Odawara Motoki, Hirakawa Yosuke, Nangaku Masaomi, Kurokawa Mineo
Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Case Rep Oncol. 2025 Apr 4;18(1):554-562. doi: 10.1159/000545498. eCollection 2025 Jan-Dec.
Fibrillary glomerulonephritis (FGN) is a rare form of immune complex-mediated primary glomerular disease frequently coexisting with malignancies or autoimmune diseases. The kidney prognosis is extremely poor, with approximately 50% of patients progressing to end-stage kidney disease within 2-4 years after diagnosis. However, no established treatment currently exists.
Here we describe a rare case of FGN diagnosed in a patient progressing from monoclonal gammopathy to multiple myeloma. The histopathological findings of the kidney biopsy were consistent with classical FGN and revealed no evidence of myeloma cast nephropathy. Albumin-dominant, Bence Jones protein-negative proteinuria further supported this diagnosis. The patient was successfully treated with anti-myeloma chemotherapies including autologous stem cell transplant, resulting in significant improvement in kidney function.
Based on our experience, secondary FGN associated with plasma cell neoplasms may represent a rare entity that responds favorably to anti-myeloma therapies. Initial investigations to rule out coexistent plasma cell neoplasms are crucial for the optimal management of FGN patients.
纤维性肾小球肾炎（FGN）是一种罕见的免疫复合物介导的原发性肾小球疾病，常与恶性肿瘤或自身免疫性疾病并存。肾脏预后极差，约50%的患者在诊断后2 - 4年内进展为终末期肾病。然而，目前尚无既定的治疗方法。
在此，我们描述一例罕见的FGN病例，该患者从单克隆丙种球蛋白病进展为多发性骨髓瘤。肾脏活检的组织病理学结果与经典FGN一致，未发现骨髓瘤管型肾病的证据。以白蛋白为主、本周氏蛋白阴性的蛋白尿进一步支持了这一诊断。该患者接受了包括自体干细胞移植在内的抗骨髓瘤化疗，肾功能得到显著改善。
根据我们的经验，与浆细胞肿瘤相关的继发性FGN可能是一种对抗骨髓瘤治疗反应良好的罕见疾病。排除并存浆细胞肿瘤的初步检查对于FGN患者的最佳管理至关重要。
