The first case of POEMS syndrome with synchronous breast cancer: What are the associated diagnostic challenges?

Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, Skin changes (POEMS) syndrome causes the following clinical manifestations: (the initial letters of which form the word POEMS) as well as extravascular volume overload, erythrocytosis/thrombocytosis, osteosclerotic lesions, and elevated vascular endothelial growth factor (VEGF) levels 1. Table 1 shows the diagnostic criteria for POEMS syndrome. The condition is diagnosed based on the presence of both polyradiculoneuropathy and a monoclonal plasma cell disorder, as well as at least one of the other three major criteria and at least one minor criterion. POEMS syndrome is often misdiagnosed because its symptoms mimic those of other disorders. In addition, it has a rapidly progressive course; therefore, early diagnosis is important. Pleural effusion, ascites, and/or cardiac effusion are the first symptoms to appear in more than half of patients with POEMS syndrome, and these conditions can become life‐threatening in some cases 2. Table 1 The criteria for POEMS syndrome Due to the abovementioned unique manifestations of POEMS syndrome, it can be difficult to achieve an early or accurate diagnosis in cases in which a patient with undiagnosed POEMS syndrome develops cancer. In other words, pleural effusion, ascites, lymphadenopathy, and bone lesions caused by POEMS syndrome might be misdiagnosed as cancer metastases if the preexisting POEMS syndrome is not detected. Herein, we present the first case report of POEMS syndrome with synchronous breast cancer and describe potential diagnostic problems associated with such cases.