Open AccessMonotypic plasma cell interstitial nephritis as the only clinical manifestation in a patient with previously undiagnosed indolent multiple myeloma
Author(s) -
Philippe Attias,
Anissa Moktefi,
Marie Matig,
Jehan Dupuis,
Céline Debiais-Delpech,
Philippe Grimbert,
Philippe Lang,
Vincent Audard
Publication year - 2016
Publication title -
medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 148
eISSN - 1536-5964
pISSN - 0025-7974
DOI - 10.1097/md.0000000000004391
Subject(s) - medicine , plasma cell , pathology , multiple myeloma , renal biopsy , interstitial nephritis , al amyloidosis , cyclophosphamide , biopsy , chemotherapy , kidney , bone marrow , immunoglobulin light chain , antibody , immunology
Predominantly monotypic plasma cell infiltrates are an uncommon renal finding in patients with malignant lymphoplasmacytic proliferation. Case presentation: We report the case of a 52-year-old man with chronic kidney disease and significant proteinuria associated with a monoclonal immunoglobulin spike (IgGκ). Kidney biopsy revealed the presence of atypical multinucleated CD138 + plasma cells with voluminous nuclei stained exclusively with a κ antibody. Electron microscopy showed mesangial and segmental parietal electron-dense, nonorganized hyaline deposits without immunogold labeling for the κ light chain. The bone marrow aspirate revealed 6% of apparently mature plasmocytes without dystrophy. We therefore concluded that the patient had an indolent multiple myeloma with specific renal involvement in the form of malignant monotypic interstitial plasmacytic infiltration. We initiated a specific chemotherapy regimen including bortezomib–cyclophosphamide–dexamethasone. After 4 months of follow-up, creatinine levels had improved slightly and free κ light-chain levels had decreased significantly within the normal range. Conclusion: This case highlights the need to consider neoplastic interstitial plasma cell infiltration systematically in patients diagnosed with an apparently benign monoclonal gammopathy and to consider adaptation of the chemotherapy regimen, to improve renal function.