Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive form of peripheral T-cell lymphoma originating from intestinal epithelial lymphocytes and is associated with a poor prognosis. We present the case of a 50-year-old woman who developed a gastrointestinal perforation, initially suspected to be due to ovarian cancer with peritoneal dissemination. The patient underwent laparoscopic adnexal resection and laparotomy for the intestinal perforation. Postoperative pathology confirmed that the cause of the intestinal perforation and enlarged adnexa was MEITL. Prompt chemotherapy was administered, followed by autologous hematopoietic stem cell transplantation. Despite rapid disease progression, effective management led to favorable treatment outcomes. Early diagnosis and timely intervention are crucial to improve the prognosis of patients with MEITL.