Introduction:COVID-19 can have severe consequences for immunocompromised individuals, including those with hematological malignancies. Prolonged infections causing pneumonia and lung injury are rare in patients with diffuse large B-cell lymphoma (DLBCL) treated with chimeric antigen receptor T-cell (CAR-T).

Case presentation:A 43-year-old male with a history of DLBCL, in remission for 2 years after CAR-T therapy, developed a persistent COVID infection, as confirmed via positive polymerase chain reaction. This slowly progressed to symptomatic hypoxemic pneumonitis and biopsy-proven diffuse alveolar damage, which responded to corticosteroid treatment.

Discussion:COVID-19 poses increased risks to patients with a history of hematologic malignancies and can lead to severe respiratory distress and mortality. Studies have shown prolonged pneumonitis may require corticosteroids for improvement. However, data on appropriate regimen for managing prolonged COVID-19 pneumonitis are lacking.

Conclusions:This case highlights challenges of the treatment of COVID-19 infections in immunocompromised individuals with hematological malignancies. Corticosteroid treatment shows benefits, but dosing and duration should be based on individual patient response. Extended monitoring, individualized treatment plans, and research are crucial for optimizing outcomes in this vulnerable population.