Immunoglobulin D Multiple Myeloma Presenting as Spontaneous Fracture.

Immunoglobulin D multiple myeloma is a rare type of multiple myeloma that usually presents as bone pain, fatigue, or weight loss. We report a case of immunoglobulin D multiple myeloma in a 53-year-old Caucasian male patient with previous medical history of anaplastic oligodendroglioma status post-surgical resection who was evaluated for back pain while mowing the lawn. His physical examination showed tenderness over the lower thoracic vertebrae with no sensory or motor impairment. Initial lab investigations showed normocytic anemia and hypercalcemia with low parathyroid hormone. Magnetic resonance imaging of thoracic spine with and without contrast showed acute pathological fracture of the T12 vertebral body with enhancing soft tissue which extended into the left ventral epidural space and left T11-T12 neural foramen. Serum protein electrophoresis showed abnormal protein band in the gamma globulin. Free light chain assay showed serum free kappa which was elevated at 3,090.0 mg/L (reference range 3.3-19.4 mg/L). Immunoglobulin D was elevated at 566.0 mg/dL (reference range <15.3 mg/dL). The patient was successfully treated with standard chemotherapy and autologous peripheral blood stem cell transplant with complete remission 3 years after starting treatment. Advancement in the treatment of immunoglobulin D multiple myeloma urge clinicians to offer their patients new treatment options especially as of the earlier presentation of this subtype of multiple myeloma and the previous reports of worse prognosis.