A case report: Diagnosis of early stage ascending colon adenocarcinoma due to concomitant lymphoma presented by ileocaecal intussusception and literature review.

Introduction And Importance: This case report describes a rare occurrence of ileocecal malignant lymphoma combined with adenocarcinoma, due to the low incidence rate of colonic malignant lymphoma.

Case Presentation: A 73-year-old female patient presented with abdominal pain and was diagnosed with "acute intussusception with intestinal obstruction" in the emergency department of our hospital. Due to the occurrence of intestinal obstruction the operation was performed, and postoperative pathology revealed a combination of ileocecal DLBCL and ascending colon adenocarcinoma at stage pT1N0M0. One month after the surgery, the patient received an R-CHOP chemotherapy regimen targeting the lymphoma from the hematology department of a local hospital. Upon reexamination after eight cycles of therapy, lymph nodes had enlarged and caused esophageal compression. Unfortunately, the patient contracted COVID-19 and was too weak to undergo any further targeted therapy treatment, and eventually passed away 17 months after the surgery.

Clinical Discussion: Synchronous cancers of the colon with malignant lymphoma and adenocarcinoma are rare but still exist. Emphasizing the importance of accurate diagnosis, this report aims to provide clinicians with a broad differential diagnosis, especially in cases where preoperative examination options are limited.

Conclusion: An accurate and comprehensive treatment plan should be tailored to the specific situations of different malignant tumors to improve the survival prognosis of patients.