Prominent dysautonomia in a patient with POEMS syndrome

Pires K, B. Hammerle M, Vianna P. Galvão PDM, L. Bergier L, V. V, França Silva MD, R. Caetano M, Perez F, Reyes KA, B. Almenara C, de Souza Lopes LC, V. Botelho D. An Atypical Case of POEMS Syndrome Associated with Autonomic Dysfunction

A 52 year old patient showed, for two years, symptoms compatible with sensorimotor polyneuropathy preventing him from walking. An electroneuromyography found a demyelinating pattern suggesting Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). The patient did not respond to corticosteroid therapy and later suffered sexual Dysfunction, Swelling, Lymphadenopathy, Hypotension, astrointestinal dysmotility, urinary retention and neuropathic pain. Analysis of the Cerebrospinal Fluid (CSF) revealed elevated protein levels and Computed Tomography (CT) scan found sclerotic bone lesions. High Vascular Endothelial Growth Factor (VEGF) levels and the results of Lambda light-Chain monoclonal gammopathy in urine protein Electrophoresis Suggested a Diagnosis of POEMS syndrome. The most striking feature, in this case, was the patient’s heightened and atypical polyneuropathy without axonal injury even after an extended period of time, and significant and atypical dysautonomia.

Nerve pathologic features differentiate POEMS syndrome from CIDP

The objective of this study is to determine if the nerve pathology in patients with POEMS syndrome is different from CIDP. We hypothesized that nerve biopsies from patients with POEMS syndrome would have more small vessels and axonal degeneration but less inflammation than CIDP.

We performed a retrospective analysis of nerve biopsies performed on “classic” CIDP and POEMS cases. Nerve biopsies were blinded and reviewed by two of the authors (EAP, PJBD). Teased fibers, paraffin-embedded sections, semithin sections and immunostains were analyzed. Small endoneurial and epineurial vessels were counted on paraffin sections with smooth muscle actin (SMACTIN) preparation to judge for neovascularization.

A total of 61 cases (35-POEMS, 26-CIDP) were included. The POEMS-group had significantly higher axonal degeneration and fewer normal myelinated fibers on teased fiber preparations. The CIDP-group had significantly more endoneurial mononuclear inflammation on paraffin sections and immunostains. Large onion-bulbs were present only in CIDP cases. A significantly higher number of epineurial vessels was present in POEMS biopsies, with a total count of 120 epineurial vessels predicted as best cutoff to differentiate both conditions (77 % specific and 54 % sensitive).

In conclusion, nerve biopsy can be helpful in distinguishing POEMS syndrome from CIDP. POEMS syndrome demonstrates more axonal degeneration and epineurial neovascularization whereas CIDP has greater endoneurial inflammation and onion-bulb formation. These findings support the idea that there are differing underlying mechanisms for these disorders, POEMS being related to paraneoplastic vasculopathy associated with angiogenic factors and CIDP related to inflammatory demyelination.