POEMS Syndrome Masquerading as Metastatic Prostate Cancer Based on PSMA Avid Lesions.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin change (POEMS) syndrome is a multisystem disorder, and it is often misdiagnosed with other entities including chronic inflammatory demyelinating polyneuropathy (CIDP). Here, we present a case of a patient with presumed metastatic prostate cancer due to prostate-specific membrane antigen (PSMA) avid lesions and a history of neuropathy not responding to conventional treatment for CIDP. His physical exam findings, in addition to an appropriate workup, led to a diagnosis of POEMS syndrome. This case highlights the importance of a high index of clinical suspicion, even when imaging suggests otherwise.