[Multiple Myeloma Without Monoclonal Component: Nonsecretory and Non-Producing. Case Report and Review].

In a small percentage, multiple myeloma (MM) lacks a measurable monoclonal component, which is termed non-secretory (NS) MM, which includes oligosecretory, true NS and non-producing NS MM (NP). The latter is notable for complete and true absence of paraprotein production. We report a case of a 66-year-old male, studied for low back pain and vertebral lytic lesions, whose blood analysis showed only hypogammaglobulinemia, with no monoclonal component. However, the vertebral biopsy identified a plasma cell tumor. Bone marrow study showed pathological plasma cells without Kappa or Lambda production. With a diagnosis of MM NS NP, he received therapy, achieving complete remission. Extremely infrequently, this group presents a higher incidence of bone lesions and t(11;14) translocation. Therapy follows the general guidelines in MM. The difference lies in the follow-up, which considers myelogram and PET-CT, in addition to monitoring of organic damage.