The patient, a 44-year-old Chinese woman, presented with chronic cough, sputum production, recurrent low-grade fevers, and chest pain. She had previously been diagnosed with secondary pulmonary tuberculosis, tuberculous pleuritis, sternal tuberculosis, and lymph node tuberculosis three years ago. A left upper lung lobe wedge resection and excision of chest wall masses were performed on her along with the administration of ATT, which proved to be ineffective. One month before she visited our institution, she sought medical attention at another hospital due to multiple subcutaneous abscesses on the head, trunk, and limbs. Cultures from an ulcer on her trunk revealed NTM infection, where M. avium was identified through DNA microarray chip array testing. Consequently, she was diagnosed with disseminated M. avium infection and treated using amikacin, moxifloxacin, clofazimine, clarithromycin, and linezolid. However, her condition did not improve after one month of treatment; instead, she gradually developed mental symptoms such as disorganized speech and hallucinations, leading to her subsequent evaluation and treatment at our hospital.
On physical examination, the patient presented with pallor and cachexia. Subcutaneous abscesses and cutaneous ulcers accompanied by yellowish purulent discharge measuring 2 to 4 cm in diameter were observed on the head, chest, abdomen, and lower limbs (Fig. 1). Laboratory investigations revealed leukocytosis (white blood cell [WBC]: 18.62×109/L, neutrophils ratio: 92%, lymphocytes ratio: 2.6%), anemia (hemoglobin [Hb]: 4.4 g/dL, red blood cell [RBC] count: 3.35×1012/L), hepatic and renal dysfunction (gamma-glutamyl transpeptidase [GGT]: 80 U/L, serum creatinine: 135 µmol/L), elevated erythrocyte sedimentation rate (ESR: 46 mm/h, normal range [NR]: 0–20 mm/h), increased C-reactive-protein levels (CRP: 103 mg/L, NR: 0–9 mg/L), elevated IgG levels (36.58 g/L, NR: 8.6-17.4g/L). The CD4 + lymphocyte count was below average at 368/µL (NR: 414–1440/µL). The anti-HIV test, TPPA (Treponema pallidum particle agglutination test), and TRUST (Tolulized red unheated serum test) were negative.
Chest computed tomography (CT) showed bilateral lung infection with enlarged lymph nodes in the bilateral supraclavicular, neck, axillary, and mediastinal regions. Additionally, thickening of the left pleura, bilateral pleural effusion, and pericardial effusion were observed. Multiple areas of bone destruction involving the sternum, numerous ribs, vertebral bodies, and scapula were also seen (Fig. 2). Cephalic magnetic resonance imaging (MRI) revealed scattered lesions on the head and cheeks, along with abnormal enhancement in the left frontal lobe, suggestive of infectious lesions and multiple abscesses (Fig. 2).
Histopathological examination of a skin abscess in the right upper abdomen revealed diffuse histiocytoid cells and lymphocytic and neutrophil infiltration in the dermis. A few small-sized fungal spore-like structures, which were positively stained with Gomori's methenamine silver (GMS), were identified in affected areas (Fig. 3). Subsequently, T. marneffei was isolated by culturing the pus from a scalp abscess (Fig. 4) and confirmed through polymerase chain reaction (PCR) sequencing. In addition, next-generation sequencing (NGS) of tissue from the left upper lobe confirmed that the initial pulmonary infection was caused by M. avium.
Thus, the patient was diagnosed with disseminated M. avium and T. marneffei co-infection. She received treatment consisting of oral itraconazole 0.2 g, twice daily, clarithromycin 0.5 g, twice daily, moxifloxacin 0.4 g once daily, ethambutol 0.625 g once daily, and doxycycline 0.1 g once daily. Subcutaneous abscesses were managed through incision, drainage, and local wound care. After two weeks of treatment, the patient became afebrile, and partial improvement was observed in cutaneous lesions. Her mental state was improved. Laboratory examination showed a slight recovery of leukocytosis (WBC: 15.44×109/L, neutrophil ratio: 90.4%). Liver and kidney function markers were improved (GGT: 39 U/L, serum creatinine: 103 µmol/L). The patient requested discharge for unknown reasons and was lost to follow-up.