Oligo-secretory myeloma in a patient with ankylosing spondylitis.

Non-secretory myeloma is a plasma cell dyscrasia characterized by the absence of serum and urinary monoclonal immunoglobulins on electrophoretic tests. Because of the lack of monoclonal protein, the identification of the disease is more difficult than for secretory myelomas. The coexistence of ankylosing spondylitis and multiple myeloma has been reported occasionally. We report a rare case of oligo-secretory myeloma coexistent with ankylosing spondylitis.