Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive form of primary gastrointestinal T-cell lymphoma. Symptoms can vary but often include fever, abdominal pain, weight loss, diarrhea, obstruction, and perforation.Disease-specific symptoms rarely present before patients reach an advanced stage, which contributes to delayed diagnosis and poor survival outcomes. Approximately half of the patients with MEITL undergo emergency surgery for acute intestinal obstruction or perforation, leading to peritonitis, septic shock, and multiple organ failure. These factors contribute to treatment delays, which are associated with a worse prognosis, particularly in the case of chemotherapy. This paper reports two fatal cases of patients with MEITL who deteriorated rapidly after emergency surgery for intestinal perforation. Patient 1 complained of persistent diarrhea, but a delayed diagnosis led to bowel perforation, and the subsequent chemotherapy treatment was canceled. Patient 2 was diagnosed relatively early, but treatment was delayed due to intestinal perforation. Despite its rarity, MEITL should be considered through a “high index of suspicion” approach when a patient complains of unexplained abdominal pain and diarrhea. This is expected to improve early diagnosis and ultimately patient prognosis.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive form of primary gastrointestinal T-cell lymphoma. Symptoms can vary but often include fever, abdominal pain, weight loss, diarrhea, obstruction, and perforation.Disease-specific symptoms rarely present before patients reach an advanced stage, which contributes to delayed diagnosis and poor survival outcomes. Approximately half of the patients with MEITL undergo emergency surgery for acute intestinal obstruction or perforation, leading to peritonitis, septic shock, and multiple organ failure. These factors contribute to treatment delays, which are associated with a worse prognosis, particularly in the case of chemotherapy. This paper reports two fatal cases of patients with MEITL who deteriorated rapidly after emergency surgery for intestinal perforation. Patient 1 complained of persistent diarrhea, but a delayed diagnosis led to bowel perforation, and the subsequent chemotherapy treatment was canceled. Patient 2 was diagnosed relatively early, but treatment was delayed due to intestinal perforation. Despite its rarity, MEITL should be considered through a “high index of suspicion” approach when a patient complains of unexplained abdominal pain and diarrhea. This is expected to improve early diagnosis and ultimately patient prognosis.