AUTHOR=Xia Pianpian , Liu Deliang , Deng Feihong , Ou Dalian , Deng Mingyang TITLE=Idiopathic AA amyloidosis presenting with initial abdominal pain: a case report and literature review JOURNAL=Frontiers in Medicine VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1640436 DOI=10.3389/fmed.2025.1640436 ISSN=2296-858X ABSTRACT=Amyloidosis is a rare disease, often secondary to chronic inflammation or autoimmune disorders, with an unclear etiology in some cases. Herein, we report a 67-year-old male patient presenting with recurrent abdominal pain and multi-system involvement. The diagnosis of AA amyloidosis was confirmed by Congo red staining of small intestinal mucosal and bone marrow biopsies. Despite comprehensive screening, no definite etiology was identified. This case highlights that amyloidosis should be considered in patients with unexplained abdominal pain and multisystem abnormalities, and early tissue biopsy is crucial for diagnosis.