Lymphadenopathy in POEMS syndrome: a correlation between clinical features and imaging findings

Lymphadenopathy is an important characteristic of POEMS syndrome, and a Castleman disease (CD)-like pathologic change in the lymph nodes is one of the major diagnostic criteria. However, the characteristics of lymphadenopathy in POEMS still have not been completely elucidated. The lymph node biopsies are available only for a small proportion of patients. A simple and safe way is needed to rule CD in or out. This study aimed to analyse the features of lymphadenopathy and estimate the role of imaging methods, including computed tomography (CT) and positron emission tomography-CT (PET/CT), in the diagnosis of lymphadenopathy in patients with POEMS syndrome. We conducted a retrospective analysis of 23 patients with confirmed POEMS syndrome. All of the patients received chest and abdominal CT scan and/or superficial ultrasound examinations. Four patients underwent PET/CT examinations, and 6 patients received lymph node biopsies. Enlarged lymph nodes (short diameter ≥ 1 cm) were found in 48% (11/23) of patients, but only 1 patient had an enlarged lymph node with a diameter ≥ 2 cm. Lymph nodes with CD-like pathologic changes from 2 patients showed increased maximum standard uptake values (SUV_max) of ¹⁸F-deoxyglucose (¹⁸FDG) on PET/CT, while lymph nodes with reactive pathologic changes from 2 other patients showed a normal metabolic PET/CT profile. The extent of lymph node enlargement in patients with POEMS was less than that in patients with CD per se. We draw the conclusion that most of the enlarged lymph nodes had diameters ≤ 2 cm, which is less than that in cases of CD per se and PET/CT may be helpful in determining whether enlarged lymph nodes are characterized by CD-like changes or not.