[1]¿p#1 The Art of Deception: Multiple Myeloma Imitating Spondyloarthritis - A Diagnostic Challenge

Key Clinical Message:Multiple myeloma can mimic spondyloarthritis, leading to diagnostic delay.HLA-B27 positivity and sacroiliac changes may mislead clinicians when typical features persist without treatment response.Persistent back pain unresponsive to therapy should prompt evaluation for malignancy to avoid misdiagnosis and ensure timely, appropriate management.AbstractRheumatic symptoms can be associated with malignancies.Sacroiliitis, though not a classic paraneoplastic syndrome, may result from malignant infiltration of sacroiliac joints, mimicking inflammatory rheumatologic diseases.Multiple myeloma (MM), a plasma cell malignancy often presenting with bone pain, can involve these joints.We report a 40-year-old male with chronic low back pain and bilateral ankle enthesitis, unresponsive to NSAIDs, along with systemic symptoms.Initial HLA-B27 positivity and imaging suggested Spondyloarthritis (SpA).However, lack of treatment response and emerging systemic features prompted further evaluation, revealing IgG kappa MM.This case underscores the diagnostic challenge of MM simulating SpA, leading to delayed diagnosis.It highlights the need for clinical vigilance and reconsideration of diagnoses in patients with atypical features or poor response to standard rheumatologic treatments, even when serologic markers are suggestive.