Case Report: First report of pneumonia and organizing pneumonia in a patient with myelodysplastic and Sweet syndromes.

The immunocompromised population is susceptible to pneumonia. The diagnosis and treatment of pneumonia in immunocompromised individuals are challenging clinical endeavors. Previous studies have identified pneumonia as a potential cause of organizing pneumonia (OP), however, the association between pneumonia and OP has not received enough clinical attention. We retrospectively evaluated a case involving infection and OP in a patient with myelodysplastic syndrome and concurrent Sweet syndrome. The diagnosis of pneumonia was confirmed through various methods: metagenomic next generation sequencing (mNGS), Giemsa-staining and fluorescence hybridization of lung tissue, as well as serum immunofluorescence antibody testing. Histopathological analysis of lung tissue revealed OP. The patient was successfully treated with a combination of antibiotics and low-dose glucocorticoids. In immunocompromised individuals, mNGS was capable of detection non- pneumophila serogroup 1. The pathological examination is important for identifying secondary OP and provides the evidence for treatment with glucocorticoids.