An Atypical Case of Guillain-Barré Syndrome Associated With Gastrointestinal Stromal Tumor

Abstract

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyneuropathy presenting with classic symptoms of progressive, symmetric muscle weakness and absent or depressed deep tendon reflexes. Molecular mimicry from an immune response to a proceeding infection inciting cross-reaction with peripheral nerves is the proposed etiology of GBS. The most common precipitant of GBS is Campylobacter jejuni infection. Rarely, GBS has been described to occur as a paraneoplastic syndrome with possible malignant triggers including small cell lung cancer and squamous cell carcinoma. We describe a case of GBS associated with gastrointestinal stromal tumor (GIST). To this author's knowledge, there are no other case reports in the literature of GBS associated with GIST. A 65 year-old man with a past medical history of hypertension and type II diabetes mellitus presented with 3 days of paresthesias of the fingers, toes, and mouth, slurred speech, vertigo, and mild hematemesis. His physical exam was significant for bilateral facial nerve palsy, dysarthria, and decreased reflexes in the lower extremities bilaterally. Laboratory results were significant for white blood cell count of 14 and hemoglobin (Hgb) level of 20.2. CT abdomen and pelvis with contrast showed a lobular soft tissue gastric mass 3.4 x 2.5 x 2.9 cm. CT head without contrast showed no acute intracranial process. Lumbar puncture revealed albuminocytologic dissociation. Nerve conduction study and needle electromyography showed demyelinating features. Based on these results, the patient was diagnosed with GBS, specifically the acute inflammatory demyelinating polyneuropathy variant. He was treated with 5 days of intravenous immunoglobulin (IVIG). For the gastric mass, he underwent endoscopic ultrasound-guided biopsy, and the pathology revealed GIST (Figures 1 and 2). Respiratory parameters remained stable, and he had mild improvement with IVIG. Campylobacter jejuni antibody was negative. For the elevated Hgb, the patient was negative for JAK2 V617F and CALR mutation, and erythropoietin was normal, making polycythemia vera unlikely. His Hgb trended down to within normal levels over the next month. The initial elevated Hgb could have been explained by hemoconcentration; however, there are murine models of GIST with KIT activating receptor tyrosine kinase mutations causing hematopoiesis. This case demonstrates a rare case of GBS associated with GIST. The patient is planned for open partial gastrectomy.Figure: Intramural lesion found in the lesser curvature of the stomach. It appears to originate from within the muscularis propria (Layer 4) and invades through the serosa. Fine needle aspiration initial cytology was suggestive of a spindle cell tumor. Sonographic appearance was suggestive of a GIST with concerning features (cystic components, large size, invading through serosa).Figure: EUS-FNA biopsy cytopathology images of GIST. A: Cytopathology conventional smear slide showing clusters of spindle cells typical for GIST (Papanicolaou stain, 200x); B: Cytopathology cell block preparation (H&E stain, 200x); C and D: Immunohistochemical stains performed on cell block section, positive staining of DOG-1 (C) and c-KIT (D) confirms the diagnosis of GIST (200x).