Abstract: TH-PO220

A Rare Case of Crescentic Glomerulonephritis Mimicking Multiple Myeloma

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Sarma, Alinda Madhab, Cleveland Clinic, Cleveland, Ohio, United States
  • Alomari, Mohammad, Cleveland Clinic, Cleveland, Ohio, United States
  • Vlasie, Anca C., Comprehensive Kidney Care, Westlake, Ohio, United States
Background

We describe a unique case of biopsy proven crescentic glomerulonephritis with an earlier presumptive diagnosis of multiple myeloma.

Methods

A 58 year old male with past medical history of hyperlipidemia and enlarged prostate was admitted to the hospital with worsening shortness of breath(SOB) and new onset generalized petechial non-pruritic rash. Vitals signs were temperature of 97.2 F, heart rate of 100 beats per minutes, and blood pressure of 112/64 mm Hg. Physical exam showed diffuse, raised, non-blanching, rash involving palms and soles, diffuse crackles on lung auscultation and bilateral foot drop. Initial laboratory studies showed hemoglobin of 8.3 g/dl, leukocytosis of 28,000(k/uL), severe acute kidney failure with creatinine of 12 mg/dl, and uric acid of 15 mg/dL. Urinalysis showed many RBCs and mild proteinuria without any cast. Based on sudden bilateral foot drop, anemia, axonal acute to sub-acute sensorimotor peripheral polyneuropathy on electromyography and elevated kappa to lambda ratio in blood workup, a presumptive diagnosis of multiple myeloma was made as an outpatient. On the day of bone marrow biopsy, patient developed severe SOB, confusion, and was brought to the hospital. On further inquiry, he endorsed a history of recurrent sinusitis for many years. Imaging studies including chest radiography, chest CT scan, brain CT scan and renal US were unremarkable. Bronchoscopy was done due to ongoing SOB, which showed diffuse alveolar hemorrhage. Further work-up showed a positive C-ANCA titer and elevated proteinase 3 antibodies. Subsequently kidney biopsy was done which was consistent with pauci-immune necrotizing crescentic glomerulonephritis(CrGN) with necrotizing arteritis. He responded very well to plasmapheresis, pulse dose steroid and cyclophosphamide.

Conclusion

Both ANCA –positive CrGN and mutiple myeloma can present with systemic manifestations of renal failure, peripheral neuropathy and skin lesions. An elevated kappa lambda ratio in this context can often perplex the clinical scenario. Careful history and serologic markers often aid in separating one from another. However, a kidney biopsy remains the gold standard in distinguishing amongst variants of RPGN to guide therapy and estimate prognosis. Prompt and aggressive plasmapharesis in addition to pulse therapy with cyclophosphamide can reverse kidney injury to a large extent.