A 45-year-old female patient was admitted to the First Affiliated Hospital of Guangxi Medical University for a sore throat lasting for 20 days on September 8, 2022. She was a teacher and had no underlying diseases. Computed tomography (CT) examination showed a space-occupying lesion. The primary lesion had not yet been determined, and the patient was admitted to our hospital. The contrast-enhanced chest CT examination showed mixed nodules in the anterior segment of the right upper lobe, inflammation of posterior segment, and middle of the right upper lobe and inferior lingual segment of left upper lobe, and mediastinal space-occupying lesions and multiple lymphadenopathy (Figure 1). The mediastinal space-occupying lesion was suspected to be a tumor, so ultrasound-guided mediastinal mass puncture was performed in the daytime operating room of our hospital. 
On admission, the patient's laboratory results were as follows: hemoglobin (HGB) was 106.60g/L, the CD4+ lymphocyte count was 549/microL, the serum high sensitivity C-reactive protein levels were 2.65mg/L (normal 0-1mg/L), serum albumin was 37.6g/L (normal 40-55g/L), glycoprotein antigen 199 54.0U/mL (normal 0-37U/mL), serum glycosylated HGB was normal, and beta-(1,3)-D-glucan (BDG) and galactomannan (GM) were negative. Liver and renal functions were normal. The human immunodeficiency virus antibody test was negative. The patient's mediastinal lesion was located near the main trachea, and infection was not ruled out, and EBUS-TBNA was performed. EBUS-TBNA showed an extratracheal pressure stenosis and unspecified echo mass at the 4-6 o'clock position in the 5cm trachea under the glottis (Figure 2). The patient's mediastinal mass tissue was sent for mNGS (KingMed Diagnostics, Nanning, China). DNA extraction was performed with the JianShi universal DNA/RNA extraction kit, and subsequently an Illumina Next 550 sequencer was used for a single-end 76-base pair sequencing strategy. A DNA library was constructed, and subsequently Burrows-Wheeler Aligner (BWA) software and the NCBI database were used for analysis. Within 24 h after receipt of the sample, the mNGS results reported Aspergillus fumigatus infection. The mNGS detected 301 sequences that could be mapped to Aspergillus fumigatus in a total of 28,759,120 sequences, and the coverage was 0.12%, making up 97.80% of the total microbe sequences (Figure 3). Tissue from EBUS-TBNA mass puncture tissue was sent for pathological examination, and 5 days after receipt of the sample, the histopathological results showed large number of neutrophil cell infiltrations and Aspergillus hyphae (Figure 4), and periodic acid-Schiff (PAS) staining of specimens was positive. Microscopic examination of EBUS-TBNA mass tissue cytological smear showed no cancer cells. Fourteen days after receipt of the sample, the EBUS-TBNA tissue fungi culture (the culture media medium was CHROMagar medium) suggested growth of Aspergillus fumigatus, and bacterial culture showed no bacteria growth. No fungi sequences were found in mNGS of the bronchoalveolar lavage (BAL) fluid. BAL-BDG and -GM were negative. Subsequently, the histopathology of ultrasound-guided mediastinal mass puncture tissue results also showed inflammatory cell infiltration and Aspergillus hyphae (Figure 4). PAS staining of specimens was positive, and the mass was considered aspergillosis with suppuration. Considering that the patient had eating disorder, gastroscopy was performed. An esophageal mass with stenosis was found, and gastroscopic biopsy of the esophageal submucosal mass tissue revealed esophageal aspergillosis. The patient was diagnosed as having mediastinal abscess with Aspergillus fumigatus infection and treated with voriconazole (0.2 g, IV infusion, q.d.) beginning September 13. Her symptoms improved, and she was discharged on September 18 on continued oral voriconazole (0.2 g, twice a day) antifungal therapy. One month after discharge, the patient was followed up by telephone. The patient was generally in good condition, and the liver and kidney functions and blood routine tests were normal. The patient is still being followed-up.
Contrast-enhanced chest CT of the patient on September 1, 2022. Space-occupying lesion of anterior upper mediastinum is shown. A low-density necrosis area can be seen on enhanced scan, which is separated from the surrounding esophagus. (A) Lung view.