Massive limb lymphedema as the initial presentation of multiple myeloma: a case report.

Multiple myeloma is a malignant neoplasm of plasma cells that primarily causes bone destruction and marrow failure. We report a female patient who presented with limb lymphedema as the first manifestation of multiple myeloma. According to guideline of the International Myeloma Working Group, this patient was diagnosed as symptomatic IgG lambda MM (Durie-Salmon stage II and International System Stage II) based on the detected values of an M-protein in the serum, clonal bone marrow plasma cells > 10% and anemia. Lymphedema was divided into primary and secondary. The most common secondary factor is malignant tumor, especially breast cancer. We excluded other causes and found no other contributing factors to the patient's massive limb lymphedema apart from multiple myeloma. After one cycle of bortezomib-based chemotherapy, the patient's lymphedema began to resolve and almost completely disappeared after 4 months. As far as we know, this is the first reported case of multiple myeloma patient who developed massive lymphedema. NF-κB signaling pathway is the main pathogenesis of multiple myeloma, and closely related with the development of lymphedema. More importantly, the symptom of lymphedema relieved after the treatment of NF-κB inhibitor Bortezomib in this patient. Based on the findings of the present study, as well as those of the literature, we proposed NF-κB may play an important role in the development of the patient's lymphedema. Further studies are warranted to explain the underlying mechanisms. But this case indicated multiple myeloma may present atypically. We should further examine and clarify the secondary factors of lymphedema, in order to early diagnosis and treatment.