Rare subtype of multiple myeloma presenting as sacroiliac joint pain in an avid golfer: a case report.

Objective: Kappa (κ) light chain multiple myeloma can be disguised as low back pain (LBP), and as such may present to a primary contact provider such as a chiropractor. The rarity and non-specific nature of the clinical presentation of this condition typically lead to a delayed diagnosis.

Case presentation: A 53-year old male avid golfer presented to a chiropractor with a chief complaint of LBP. He was diagnosed with sacroiliac joint dysfunction. His pain was initially improving with chiropractic management. The character of his pain changed, and the chiropractor referred for further imaging. He was subsequently diagnosed with κ light chain multiple myeloma.

Summary: This case presentation highlights that spinal malignancy is a possible cause of LBP. It reminds the clinician to investigate signs and symptoms that could lead to a suspicion of malignancy, to monitor patient progression, and consider further evaluations if the expected response to treatment is not achieved.