Recurrent Intra-abdominal Low-Grade Fibromyxoid Sarcoma Managed With Multivisceral Resections: A Case Report.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue sarcoma with deceptively bland histology. There is a recognized risk of late local recurrence and metastasis. Intra-abdominal presentations are uncommon and may remain clinically silent until the tumor is large, at which point complete resection can require multivisceral surgery. We report a 61-year-old woman diagnosed with intra-abdominal LGFMS in 2021. Histopathology showed classic fibromyxoid architecture with strong MUC4 expression, focal CD34 positivity, and a Ki-67 index of approximately 6%. After a margin-negative ileocecal resection, systemic therapy was administered. Multifocal intra-abdominal recurrence developed in early 2024 and was completely resected. Further recurrence occurred in 2025. The tumor involved the sigmoid colon, small bowel, urinary bladder, and spleen. Wide multivisceral resection was performed, including sigmoid colectomy, two small-bowel resections, partial cystectomy, splenectomy, and excision of additional nodules. Pathology confirmed recurrent LGFMS consistent with the original tumor, with negative surgical margins. The patient remains disease-free six months after the most recent surgery. This case underscores the propensity for persistent intra-abdominal LGFMS recurrence and supports complete surgical excision, often requiring multivisceral resection, as a key strategy for disease control in resectable recurrent disease.