A 51-year-old woman presented at another hospital four years ago with complaints of fever and back pain. A chest computed tomography (CT) image showed multiple nodular shadows (Fig. 1A), so she was referred to our hospital for further evaluation. She had no history of asthma, had never smoked, and had no significant family history. Although she had a low-grade fever, her physical examination, including chest auscultation, was normal. Her laboratory findings were as shown in Table 1 (left column), which included no significant elevation of tumor markers. We performed lung biopsies of the left upper lobe using video-assisted thoracic surgery. The histological evaluation of the lung specimen showed the infiltration of lymphocytes and granulomas with necrosis (Fig. 2A). There were no findings suggesting mycosis or acid-fast bacillus infection, and the specimen was negative for M. tuberculosis PCR. Therefore, we diagnosed her with NSG. Subsequently, the multiple nodular shadows, and her fever and back pain, gradually improved. We continued to follow her even though she did not require treatment.
Four years after her initial diagnosis, she came to our hospital for regular follow-up without any symptoms and abnormal chest CT shadows (Fig. 1B). Three weeks after that, she complained of acute back pain and high fever (>38  C) for a few days. She returned to our hospital for further evaluation. Her body temperature was 38.0  C. There were no remarkable findings on a physical examination, including chest auscultation or skin lesions. Her laboratory findings at this presentation are shown in Table 1 (right column). Although the antinuclear antibody was elevated, angiotensin-converting enzyme, lysozyme, anti-myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA), anti-serine protease 3-ANCA, and QuantiFERON were within the normal range.
Both chest radiography and CT showed multiple nodular shadows in both the lung fields. These shadows consisted of irregular margins and a hypovascular central area, which suggested necrosis (Fig. 1C), although there was no cavity formation. The sputum culture revealed no significant bacteria, including acid-fast bacilli. A Gallium-67 scan image demonstrated the increased uptake in the multiple lung nodules (Fig. 3A). A bronchoscopy was performed for further diagnosis. Transbronchial biopsy of nodular shadow revealed the infiltration of lymphocytes and macrophages in the alveoli. Samples of bronchoalveolar lavage fluid showed an elevated lymphocyte proportion (31.3%), and CD4/CD8 ratio was within the normal limit (3.19).
The bronchoscopy revealed a small nodular lesion in the trachea (Fig. 3B). The biopsy sample of this lesion revealed infiltration of lymphocytes and granulomas with necrosis (Fig. 2B), which was similar to the surgical lung biopsy obtained four years ago. The specimen was also negative for M. tuberculosis PCR. Therefore, we diagnosed her with the recurrence of NSG.
As her back pain, high fever, and chest radiography worsened, we initiated corticosteroid therapy with oral prednisolone 40 mg/day. Her symptoms dramatically improved within a week, and the multiple nodular shadows in both lung fields resolved almost completely after three months (Fig. 1D). Oral prednisolone was gradually decreased to 15 mg/day over three months without any recurrence.