Supplementary Material for: Neurofibromatosis Type 1 presenting as bleeding jejunal gastrointestinal stromal tumour

Introduction: Gastrointestinal stromal tumours (GISTs) are an important, though uncommon, cause of obscure gastrointestinal bleeding and may rarely be associated with genodermatoses such as Neurofibromatosis Type 1 (NF1). NF1-related GISTs have unique phenotypic features compared with sporadic GISTs and may elude diagnosis due to their predilection for the small bowel. Case Presentation: We report a case of a 45-year-old Singaporean woman with café-au-lait macules and cutaneous neurofibromas who presented with occult obscure gastrointestinal bleeding and was eventually discovered to have a bleeding jejunal GIST. This finding, considered together with her cutaneous signs, eventually led to the diagnosis of NF1. Conclusion: Genodermatoses and their gastrointestinal complications are likely under-reported in adult Southeast Asian populations and deserve greater awareness from gastroenterologists practising in this region.