A Teaching Case: Persistent COVID-19 Pneumonia Resembling Cryptogenic Organizing Pneumonia in a Patient With Remitted Lymphoma.

We report a case of a female patient in her 50s, previously diagnosed with follicular lymphoma (now in complete remission), who was admitted to our hospital due to antibiotic-resistant pneumonia lasting a month. The patient had contracted coronavirus disease 2019 (COVID-19) pneumonia a year earlier and exhibited persistent hypogammaglobulinemia. Chest CT scans revealed wondering ground-glass opacities and consolidations initially suggestive of cryptogenic organizing pneumonia (COP). Despite repeatedly negative nasopharyngeal SARS-CoV-2 tests, the virus was detected in the bronchoalveolar lavage fluid (BALF) using the BioFire FilmArray Respiratory Panel 2.1. She was subsequently diagnosed with COVID-19 pneumonia and responded well to treatment with remdesivir (RDV) and intravenous immunoglobulin. The SARS-CoV-2 variant in the BALF was suspected as the Omicron variant (XBB.1.16), prevalent in the area at the admission, indicating a re-infection rather than a recurrence. This case underscores the protracted nature of COVID-19 pneumonia in immunocompromised patients and the risks of false negatives in nasopharyngeal SARS-CoV-2 tests. Direct SARS-CoV-2 measurement from BALF can be crucial in such cases. A COP diagnosis based solely on imaging and administering corticosteroids without antiviral treatment might exacerbate the situation by reactivating SARS-CoV-2. Given the current pandemic, clinicians should be aware of the potential for persistent or recurrent COVID-19, particularly in immunocompromised patients.