multiple myeloma, follow-up, hemoglobin, immunoglobulins, paraproteinemias, respiratory rate, bone lesion, bortezomib, computed tomography/positron emission tomography imaging, c-reactive protein, increased

Background Multiple myeloma (MM) is the second most common hematological malignancy characterized by plasma cell (PC) infiltration of the bone marrow. Unfortunately, better imaging techniques convey multiple reports about increased incidence of the so-called extramedullary disease of MM (EM), an aggressive, mostly resistant entity with poor prognosis for patients. EM probably develops because of 'bone marrow escape' of PC subclone that migrates out of the BM infiltrating soft tissues losing dependence on the BM microenvironment, either partially or completely. There are two types of EM - primary, found at the time of MM diagnosis, and secondary, found at the time of MM relapse. However, there are very few reports about EM.