S6491 Gastrointestinal Involvement in POEMS Syndrome Presenting as Gastroparesis: A Case Report

Introduction: Gastroparesis is a syndrome of delayed gastric emptying of solids in the absence of a mechanical obstruction with cardinal symptoms of nausea, vomiting, early satiety, bloating, and upper abdominal pain. Most cases are idiopathic, diabetic, iatrogenic or postsurgical. Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes syndrome (POEMS) is a rare paraneoplastic syndrome of multisystem disorder associated with plasma cell discraysia. Gastrointestinal (GI) involvement is not a typical feature of POEMS but may present in rare cases. Here we report a rare case of POEMS-associated gastroparesis. Case Description/Methods: A 55-year-old man with a history of IgG kappa M-spike presented with nausea, vomiting, weight loss, progressive neuropathy, and diffuse skin ulcers. Esophagogastroduodenoscopy (EGD) showed a large amount of retained food contents but was otherwise normal. Biopsies showed marked chronic gastritis with reactive polytypic plasmacytosis of the gastric mucosa consistent with autoimmune gastritis. H. pylori was positive, for which he was treated. MR enterography showed severe distention of gastric antrum and no masses. Gastric emptying study showed 82% retention at 240 minutes. Colonoscopy was normal. The patient was initiated on steroids and vomiting resolved. Labs were notable for anemia, normal CA 19-9, and C-reactive protein 58(<5) mg/L. Disease activity parameters were elevated: VEGF 63 pg/ml, (0-115), IL-6 33.7 pg/mL, (0-13), immunoglobulin A <10 mg/dl (66-433), immunoglobulin M 116 mg/dL (45-281), immunoglobulin G 3051 mg/dL (637 – 1741) that improved on treatment with daratumumab, lenalidomide, and dexamethasone. Before repeat EGD/GES could be performed to assess response to treatment, the patient collapsed due to PEA arrest of unclear etiology and expired. Discussion: Rare cases of GI involvement in POEMS in patients with monoclonal gammopathy have been reported, and clonal plasma cell infiltration is a common histological feature often found on gastric biopsy. In our case, treatment of POEMS syndrome was associated with resolution of emesis, possibly through improvement of gastric inflammation and gastroparesis. Dogan et al. reported a case of resolved chronic diarrhea in which endoscopic and histological inflammatory features of the stomach and colon normalized 45 days after the initiation of chemotherapy. While GI symptoms are not a typical feature of POEMS syndrome, it is important to consider gastroparesis as secondary to rare systemic illnesses after ruling out more common etiologies.