Case presentation
An 81-year-old female patient presented to our institution with gross hematuria, fatigue, nausea, anorexia, and progressively deteriorating renal function. ANCA enzyme immunoassay revealed a perinuclear staining pattern (p-ANCA) and serum anti-myeloperoxidase (MPO) antibody titer of 119 units/ml. She initially improved with intravenous methylprednisolone. However, after tapering the glucocorticoids and starting cyclophosphamide, her appetite and general state worsened, with increased body temperature, but serum creatinine and C-reactive protein concentrations and the erythrocyte sedimentation rate keep being decreased. Intravenous immunoglobulin and antibiotics had no effect. Intensive immunosuppressive therapy was initiated, and just as she improved, she suddenly developed purulent and blood-tinged sputum. Computed tomography of the chest showed a solid nodule with cavitation in the dorsal segment of the left lower lobe. Sputum culture revealed growth of Mucor species. Amphotericin B liposomes (LAMB) were administrated, and the cumulative dosage was 2.0 g with 2 months’ treatment duration. Finally, repeat sputum culture was negative, the nodular lesion disappeared, and only a cystic air space remained. No nephrotoxicity with LAMB was seen.