Pneumocystis jirovecii and Legionella pneumophila coinfection in a patient with diffuse large B-cell lymphoma: A case report

BACKGROUND Diffuse large B-cell lymphoma (DLBCL) is a common non-Hodgkin's lymphoma. R-CHOP is a protocol for long-term chemotherapy for DLBCL patients. Long-term chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients. CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii (P. jirovecii) and Legionella pneumophila (L. pneumophila) in a patient with DLBCL. The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection. P. jirovecii and L. pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining, isothermal amplification and metagenomic sequencing. CONCLUSION To the best of our knowledge, this is the first case of P. jirovecii and L. pneumophila coinfection found in a DLBCL patient. Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.