Complete response in a frail patient with high-grade B-cell lymphoma to only one cycle of R-CHOP or to prolonged COVID-19?

BACKGROUND: COVID-19 infection increases mortality in hematological malignancies. In a large meta-analysis, patients aged 60 years and older had a significantly higher risk of death than patients under 60 years of age [1]. Furthermore, a high risk of death and reduced survival in patients receiving B cell depletion therapy with prolonged COVID-19 infection was reported in a recent study [2]. High-grade B-cell lymphomas are classified as morphologically aggressive lymphomas with the presence of a high mitotic index and Ki-67 proliferation rates. They demonstrate aggressive behavior clinically as well as morphologically, and COVID-19 infection is an important factor that increases mortality in these patients. Herein, we present an elderly patient with a diagnosis of high-grade B-cell lymphoma, in whom a complete response was observed after prolonged COVID-19 infection. CASE SUMMARY: An 81-year-old female patient received her first cycle of R-CHOP (rituximab, cyclophosphamide, vincristine, and prednisolone) treatment after being diagnosed with high- grade B-cell lymphoma. After being discharged from the hospital, the patient was referred to the emergency department with complaints of fever and fatigue when she came for the second cycle of chemotherapy. Her COVID-19 PCR test was found positive. She was admitted to the infectious diseases service and favipiravir treatment was started. On the 24th day of hospitalization, it was decided to perform interim FDG-PET/CT (Fluorodeoxyglucose - Positron Emission Tomography/Computed Tomography) scan at a time that her PCR (Polymerase Chain Reaction) test was still positive. A complete metabolic response was detected in her imaging. On the 26th day, the PCR test became negative and the patient was transferred to the oncology service and received the second cycle of R-CHOP treatment. CONCLUSION: Our case emphasizes that antitumor effect could be seen in a patient with SARS-CoV-2 infection and a hematologic malignancy. It also highlights being alert to prolonged COVID-19 infection in patients receiving B-cell depletion therapy.