S6167 Non-Paraneoplastic Anti-Hu Mediated Chronic Intestinal Pseudo-Obstruction in the Setting of Sarcoidosis: A Case Report

Introduction: Chronic intestinal pseudo-obstruction (CIPO) is a rare disease affecting gastrointestinal motility that experiences delays in diagnosis. It has been associated with anti-Hu, typically related to paraneoplastic syndromes. We present a case of CIPO that is anti-Hu mediated but not related to a malignancy. Case Description/Methods: A 40-year-old woman presented with epigastric pain in November 2014. Imaging showed liver lesions for which she had a liver biopsy in March 2015. Pathology revealed granulomatous inflammation. Her initial findings were deemed secondary to toxoplasmosis as supported by serologies at the time. She then did not require admission until 2018 when she presented with obstructive symptoms. Subsequently, she was admitted 36 times with symptoms of obstruction between 2020 and 2024. During this time, she underwent extensive endoscopy, infectious testing, imaging, serologic workup, and diagnostic laparoscopies with no clear etiology identified. Endoscopic pathology in 2022 showed increased intraepithelial lymphocytes of the duodenum. CIPO was considered but not pursued since she did not have symptoms in between admissions. Sarcoidosis was pursued given prior liver biopsy and her mediastinal lymph nodes revealed non-necrotizing granulomas. However, since small intestine involvement is rare and steroid use could increase her risk of perforation, treatment was deferred. She followed in clinic and was treated aggressively for constipation with secretagogue with decreased frequency of hospital admissions. Due to ongoing admissions without an etiology, Mayo Clinic’s autoimmune gastrointestinal dysmotility evaluation panel was sent in 2025, which revealed anti-Hu positivity. Evaluation for a primary malignancy was unrevealing, but 2 enlarging lung nodules were found. These were felt to be related to her sarcoidosis given her findings thus far. She was evaluated in sarcoidosis clinic and her sarcoidosis with non-paraneoplastic anti-Hu positivity was deemed to likely be associated with her obstructions. As such, plans were made to trial methotrexate. Discussion: In this case, the patient underwent extensive workup prior to pursuit of CIPO as a diagnosis and identification of sarcoidosis that may warrant treatment despite not being a classic presentation. It may be worth considering early testing for autoimmune or paraneoplastic syndromes after a patient has had a few hospital admissions relating to bowel obstruction as this can reveal underlying pathology that may otherwise be overlooked.