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.

引言：胃肠道间质瘤（GISTs）虽然相对罕见，但却是引起不明原因胃肠道出血的重要原因，且偶尔可能与神经纤维瘤病I型（NF1）等基因性皮肤病变相关。与散发型GISTs相比，与NF1相关的GISTs具有独特的表型特征，由于其偏好在小肠发生，可能逃过诊断。病例报告：我们报道了一例45岁的新加坡女性患者，她出现咖啡斑和皮肤神经纤维瘤，伴有隐匿性不明原因胃肠道出血，最终被诊断为出血性回肠GIST。结合其皮肤症状，这一发现最终导致了对NF1的诊断。结论：在成年东南亚人群中，基因性皮肤病变及其胃肠道并发症可能被低估报告，且值得在此地区行医的胃肠病学家给予更多的关注。