Thoracic pain (especially with nocturnal pain) is a red flag for serious disease. While lytic lesions characteristic for myeloma on a skeletal survey, lack of bone density can be a feature. Bone chemistry is important in a patient with myeloma but it would be unusual for abnormalities in bone chemistry (e.g. hypercalcaemia) to present as bone pain in isolation. Around 20% of cases of myeloma will have non diagnostic immunoglobulins but positive urine free light chains (Bence–Jones protein).

Myeloma (NHS Choices)