POEMS syndrome: diagnosis, treatments, and outcomes.

POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes) syndrome is a complex paraneoplastic syndrome related to a lambda-restricted low-tumor burden neoplasm. The diagnosis must be considered in the context of what might otherwise be believed to be a "monoclonal gammopathy of undetermined significance," with unusual features including, but not limited to, peripheral neuropathy, thrombocytosis, and extracellular volume overload. Once a diagnosis of POEMS syndrome is made, besides very specific supportive care, the treatments resemble those of multiple myeloma or solitary plasmacytoma of the bone. Based on case series, autologous stem cell transplant is still a favored therapy with durable remissions even without maintenance therapy. Even before the era of therapeutic monoclonal antibodies, bispecific T-cell engagers, and chimeric antigen receptor antibodies, 10-year overall survival approached 80%. Patients achieving a complete hematologic response have a progression-free survival of 88% even without maintenance therapy. Herein, a case of a patient with a less-than-average outcome is described to highlight some of the long-term challenges and complexities of managing patients with POEMS syndrome.