Skull mass as the first manifestation of recurrent multiple myeloma in a renal transplant patient.

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.