A 63-year-old female patient was admitted in July 2022 with intermittent cough and poor appetite for three months, accompanied by two weeks of headache. The patient had experienced paroxysmal cough without significant sputum production since April 2022, and the cough initially went unnoticed. Subsequently, the aforementioned symptoms recurred intermittently. In early June 2022, the patient sought outpatient care at a tertiary hospital in Nanjing, where chest computed tomography (CT) indicated interstitial pneumonia, and rheumatologic autoantibody testing yielded positive results for anti-Sjogren's syndrome A. A diagnosis of interstitial pneumonia associated with Sjögren's syndrome was made, and treatment with prednisone (30 mg qd) and cyclosporine (75 mg, bid) was initiated. The patient's cough improved gradually following treatment. A follow-up CT on July 8, 2022 showed marked absorption of interstitial pneumonia, with a newly developed circular nodule in the right upper lobe measuring approximately 22 mm × 21 mm. However, a week later, the patient developed a fever, with a peak temperature of 39.2 °C, prompting her visit to our hospital. The patient had no significant past medical history. The patient had no significant personal history, reproductive history, or family history. On admission, the patient's vital signs were as follows: temperature 36.5 °C, pulse rate 105 beats/min, respiratory rate 18 breaths/min, blood pressure 120/83 mmHg, and SpO2 94% (without oxygen supplementation). The patient was alert, breathing normally, without cyanosis of the lips, and the patient had no superficial lymph node enlargement. Decreased breath sounds were auscultated in the right upper lung, while no crackles or wheezes were detected in either lung. No abnormalities were observed on cardiac auscultation or abdominal palpation, and there was an absence of lower extremity oedema and pathological reflexes. The highly C-reactive protein (CRP) level was > 10.00 mg/L. Routine blood tests were as follows: white blood cell count 6.00 × 109/L, neutrophil percentage (N%) 80.6%, absolute lymphocyte count 0.83 × 109/L, lymphocyte percentage (L%) 13.8%, haemoglobin 133 g/L, and platelet count 143 × 109/L. Biochemical parameters included total bilirubin 22.7 µmol/L, direct bilirubin 12.5 µmol/L, alanine aminotransferase 46.9 U/L, albumin 29.4 g/L, and globulin 29.9 g/L. The lymphocyte subset counts were as follows: CD4+ T cells 83 cells/μL and CD8+ T cells 601 cells/μL. Rheumatologic autoantibody tests yielded positive results for antinuclear antibodies. In addition, tumour marker tests, sputum fungal and bacterial cultures, acid-fast bacilli smears, galactomannan (GM) tests, beta-glucan (G) tests, cryptococcal antigen qualitative assays, tuberculosis infection T-cell assays, and respiratory pathogen IgM screening all yielded negative results. Lesion changes occurred on chest CT at different periods.