Urine dipsticks only detect albumin and not all proteins, including light chains (i.e Bence Jones Protein). Therefore, a patient with Multiple Myeloma who has a large amount of light chains in the urine will not have a conventional positive dipstick. 
1. Dimopoulos M, Kyle R, Fermand JP, Rajkumar SV, San Miguel J, et al. Consensus recommendations for standard investigative workup: report of the International Myeloma Workshop Consensus Panel 3. Blood. 2011 May 5. 117 (18):4701-5.
A common finding described on computed tomography (CT) imaging. A disease with a peribronchovascular distribution…