Long-Term Recurrence-Free Survival of an Elderly Patient With Diffuse Large B-cell Lymphoma in the Setting of Rituximab-Containing Therapy and a Natural History of Gastric Adenocarcinoma

Diffuse large B-cell lymphoma (DLBCL) is a high-grade malignancy. We present a case of a 97-year-old female with gastric cancer and DLBCL in whom remission with rituximab-containing minimum chemotherapy was sustained for 10 years. As she had severe adverse effects, she refused further treatments for both tumors. Ten years after the initial treatment, examinations showed several tumors in the lungs, the right pleura, and the liver, as well as advanced gastric cancer. She eventually passed away, and the autopsy revealed that multiple tumors were not lymphoma, but adenocarcinoma. This case report is a valuable addition to the literature as it analyzes whether rituximab-containing minimum chemotherapy is effective for elderly DLBCL and delineates the natural history of gastric cancer.