A Rare Case of Renal Recovery in a Young Patient with Multiple Myeloma

Multiple myeloma (MM) is an uncommon hematologic malignancy accounting for 1% of all malignancies. Renal involvement is a common complication of MM. Rapid intervention to reverse renal dysfunction may be critical for management, especially in patients with light chain cast nephropathy. Recovery rate ranges from 5% to 15%. We describe an atypical presentation of MM in a young patient who presented with severe renal insufficiency requiring renal replacement therapy and achieved complete renal recovery with chemotherapy. 1. Introduction Multiple myeloma (MM) is described as a hematologic malignancy characterized by the neoplastic proliferation of a single clone of plasma cells producing a monoclonal immunoglobulin. The most common location for this neoplastic proliferation is bone marrow, but extraskeletal disease is described as well. MM accounts for approximately 1% of all malignancies and 10% of all hematologic malignancies [1]. The annual incidence in the US is approximately from 4 to 5 per 100,000 [2]. MM occurs in all races and occurs in all geographic locations, but the incidence varies by ethnicity. African Americans are 2-3 times more likely than whites to develop MM [3, 4]. Asians and Mexicans both have a lower incidence than whites. MM is more frequent in men than in women (approximately 1.4？:？1) [5]. MM has been known to be a disease of older adults, where the median age at diagnosis is 66 years. Only 10 percent are younger than 50 years, and a mere 2 percent of patients are younger than 40 years [6, 7]. The most common signs and symptoms of MM are anemia, bone pain, abnormal renal function, fatigue, and hypercalcemia [6]. Often the diagnosis of MM results from a workup of unexplained renal disease due to the excessive production of light chains that accumulate in the kidneys causing damage. Renal disease is a common feature in MM, and it is estimated that a serum creatinine of >1.3？mg/dL is present in approximately 50% of cases [6]. Severe renal insufficiency (serum creatinine >2.5？mg/dL) is seen in 15–20% of cases [8]. Several studies have shown that renal lesions in patients with MM vary. Cast nephropathy was found in 40–60%, 19–26% had light-chain disease, 4–30% had amyloidosis, and <1% had cryoglobulinemic renal disease [9]. It has been stated that the risk of renal failure is associated with the amount of light-chain excretion [10]. The presence and severity of renal insufficiency in patients with multiple myeloma is associated with poor prognosis in regards to both morbidity and mortality [10]. 2. Case Report A previously healthy,