A treacherous case of primary non-Hodgkin lymphoma of the bone: appearances can be deceptive.

Introduction: Primary lymphoma of the bone constitutes an extremely rare but distinctive clinical entity, accounting for approximately 3% of all primary bone malignancies and less than 1% of all non-Hodgkin lymphomas.

Case Presentation: We report a rare case of a male patient with an atypical clinical presentation of non-Hodgkin primary lymphoma of the bone, initially misdiagnosed as ankylosing spondylitis. To our knowledge, this is the first case in the literature in which magnetic resonance imaging was contra-indicated.