Atypical Presentation of Multiple Myeloma as Acute Renal Failure of Unknown Etiology: Two Case Reports.

Multiple myeloma (MM) is a clonal plasma cell proliferative disorder that accounts for 1% of all cancers (Rajkumar). It is a disease of older adults, presenting with anemia, bone pain, and end-organ damage in the form of CRAB features. With increasing awareness regarding this entity and the availability of more-sensitive diagnostic modalities, involvement of younger age-groups with atypical presentations is becoming more common. Newer case series report that nearly 50% of MM cases present initially with renal failure of unknown etiology (Shankar et al.), highlighting the unique role of the nephrologist in the diagnosis of this condition. In these two case reports, we wish to highlight two cases presenting with acute renal failure of unknown etiology, who were subsequently diagnosed to have occult MM with light chain deposition disease (LCDD).