Synchronous retroperitoneal diffuse large B-cell lymphoma with colon cancer: A case report

Abstract

Colon cancer and diffuse large B-cell lymphoma (DLBCL) are common malignancies, but retroperitoneal DLBCL is rarely reported. The co-occurrence of colon cancer and retroperitoneal DLBCL is exceedingly uncommon. In clinical practice, colon cancer is primarily treated with surgical resection, although for patients with advanced disease who are not candidates for radical resection, comprehensive therapies such as chemotherapy and immunotherapy might be considered. In contrast, DLBCL patients are mainly treated with anti-tumor chemotherapy, and the core anti-lymphoma medicines such as vincristine and doxorubicin are rarely used to treat colon cancer. Therefore, when invasive DLBCL and colon cancer co-occur, it is challenging to balance the two kinds of malignant tumors and design practical treatment approaches. Due to the scarcity of cases, the optimal treatment regimen has yet to be determined. If colon cancer is treated first, therapy for aggressive lymphoma may be delayed, worsening the prognosis. Furthermore, treating lymphoma first may result in the advancement of colon cancer, reducing patients' chances of survival. Clinicians often face these dilemmas while dealing with such situations. We report a case of synchronous retroperitoneal DLBCL with sigmoid adenocarcinoma to share our experience in diagnosis and treatment.