Background: Although there are a few reports of recurrence of multiple myeloma in the transplanted kidney, recurrence of multiple myeloma (MM) presenting, as an isolated lesion in the brain, has been reported rarely.
Case report: Here we present a 60-year-old woman who underwent a kidney transplantation following a rise in her BUN and creatinine, having shown advanced tubulo-interstitial nephritis in her native kidney microscopic biopsy examination. Two years following her renal transplantation, she presented with a skull mass which was regarded as a possible meningioma. A biopsy of her transplanted kidney was performed due to her constantly raised BUN/Cr which revealed "Myeloma cast nephropathy".
Conclusion: We describe an unusual presentation of recurrent multiple myeloma, as a brain mass mimicking meningioma and simultaneously in the transplanted kidney, and discuss the differential diagnosis of the patient's primary disease.