Clinical mismatches leading to the misdiagnosis of multiple myeloma as diabetic nephropathy: A case report

BACKGROUND Diabetic nephropathy (DN), characterized by the presence of protein in the urine, is a primary contributor to chronic kidney disease. Nonetheless, the clinical considerations often overlook non-diabetic renal disease (NDRD). Multiple myeloma (MM) is a blood cancer, which can present as renal impairment like DN, leading to delays in diagnosis and prognosis. CASE SUMMARY A 60-year-old lady with 12 years of type 2 diabetes (T2D) developed severe anemia with progressive renal insufficiency. Contrary to the occurrence of DN, her clinical profile revealed a suboptimal blood glucose control but three major mismatches. These mismatches were disproportionately severe anaemia not in keeping with the degree of renal impairment; a large gap between high total urinary protein and low albuminuria; and absence of hypertension or edema despite advanced renal failure. A serum protein electrophoresis and bone marrow biopsy were found to confirm the presence of λ-type MM (stage III, group B). Following systemic chemotherapy (bortezomib/dexamethasone), her renal function and anemia improved significantly. CONCLUSION When patients with T2D present with atypical renal features, clinicians should consider the possibility of NDRD. Identifying clinical mismatches is essential for the early diagnosis of MM in patients with diabetes.