Rationale: Gastrointestinal stromal tumor and mesenteric fibromatosis are rare mesenchymal tumors. Coexistence of these two diseases is uncommon, with only a few anecdotal reports of individuals.
Patient concerns: Clinical data and treatment of a 43-year-old man with subsequent mesenteric fibromatosis from gastrointestinal stromal tumor are summarized. The Ethics Committee of The Second Affiliated Hospital, College of Medicine, Zhejiang University approved this study, and the patient provided written informed consent form.
Diagnoses: The initial diagnosis of the recurrent mesenteric mass was recurrent gastrointestinal stromal tumor.
Interventions: The operation was performed as possible at the time when the mass was found after the first surgery.
Outcomes: The diagnosis was revised as mesenteric fibromatosis according to the postoperative immunohistochemical staining. The postoperative condition was normal without adjuvant therapy and no recidivation has been found.
Lessons: The potential for the coexistence of gastrointestinal stromal tumor and mesenteric fibromatosis should always be considered.