What is the classic urinary finding in multiple myeloma?

The classic urinary finding in multiple myeloma is the presence of Bence Jones proteins, which are free light chains of immunoglobulins that are excreted in the urine. Multiple myeloma is characterized by the overproduction of abnormal plasma cells that produce monoclonal immunoglobulins. In this condition, these light chains can be released into the bloodstream and subsequently filtered by the kidneys, leading to their excretion in the urine.

The detection of Bence Jones proteins is clinically significant because it can be used as a diagnostic marker for multiple myeloma. The presence of these proteins in the urine can help confirm a diagnosis, especially when correlated with other clinical findings and laboratory results, such as hypercalcemia, anemia, and skeletal lesions. Furthermore, urine protein electrophoresis or immunofixation can be utilized to identify these Bence Jones proteins specifically.

In contrast, the other options do not appropriately characterize the urinary findings associated with multiple myeloma. Increased urine phosphate relates more to conditions affecting bone metabolism, glucosuria is more commonly associated with diabetes or renal glycosuria, and proteinuria with high albumin could indicate different renal pathologies such as nephrotic syndrome or glomerulonephritis, but