A 74-year-old woman experienced parotid gland enlargement and swelling of the eyelid margins on the left side. Following a biopsy, the patient was diagnosed with IgG4-related Mikulicz’s disease. Her symptoms improved spontaneously. Three years later, she presented with swelling of the eyelid margins on both sides accompanied by a visual disorder. The patient was referred to the departments of ophthalmology, rheumatology and, connective tissue disorders. CT which revealed extensive abnormalities in the trachea and both bronchi, was subsequently referred to our department.
The patient’s vital signs were as follows: body temperature, 36.8 ℃; heart rate, 66 beats/min; blood pressure, 163/73 mmHg; and SpO
2, 97% (on room air). Breath sounds were within the normal range. Routine blood investigation results were normal. Immunological examination results revealed the following: IgG, 3028 mg/dL (normal range: 861–1747); IgG4, 1994 mg/dL (normal range: 11–121); IgA, 220 mg/dL (normal range: 93–393); IgM, 39 mg/dL (normal range: 50–269); and IgE, 2143 IU/mL (normal range: 28–138). The angiotensin-converting enzyme level was 12.8 U/L, and IL-2R was 960 U/mL. Chest CT revealed extensive multiple nodules and mucosal oedema of the trachea and both bronchi; however, no ground-glass nodules or lung masses were observed (shown in Figs.
1 and
2). Pulmonary function tests revealed that the vital capacity (VC) was 2.02 L/min, %VC was 90.6%, forced expiratory volume in one second (FEV
1) was 1.25 L, and FEV
1% was 67.57%, peak expiratory flow volumes (PEF) was 2.13 L/s, suggesting an obstructive disorder. On flexible bronchoscopy under sedation, extensive lesions were observed from the middle of the trachea to the carina and further on both segmental bronchi. The nodules were continuous with the normal respiratory tract mucosa, and the surfaces were smooth with little neovascularisation. It was difficult to pass an Olympus BF-1TQ290 through the left carina 1 and the right carina 2 (shown in Fig.
3) because of the severe mucosal oedema. We tried to perform a biopsy using standard forceps, but the lesion was too solid to obtain an adequate amount of specimen (Fig.
4a). Subsequently, we used a 1.9 mm cryoprobe (ERBE; Medizintechnik, Tübingen, Germany) under intubation. Minimal bleeding was observed during the procedure. Following cryobiopsy (Fig.
4b), hematoxylin and eosin staining revealed a dense, non-monotonous lymphoplasmacytic infiltrate with focal interstitial fibrosis in the tracheal mucosa (shown in Fig.
4c). Immunostaining for IgG4 and IgG revealed abundant IgG4 + plasma cells, with > 40 IgG4 + plasma cells per high power field and an IgG4/IgG ratio of > 40% (shown in Fig.
4d, e); thus, these findings satisfied the diagnostic criteria for IgG4-RD. No malignant cells or areas were positive on Congo red staining. Consequently, the patient was diagnosed with IgG4-RLD. Treatment commenced with oral prednisolone at 30 mg/day (0.5 mg/kg/day). Subsequently, the symptoms of bilateral swelling of the lid margin and visual disorder rapidly improved. We continued prednisone at 30 mg/day for 4 weeks and then tapered it by 2.5-5 mg every 2–4 weeks [
3,
6]. The symptoms did not relapse. The radiological findings on chest CT after 6 months of treatment are shown in Fig.
5. Bronchoscopy revealed only a few nodules (shown in Fig.
6). The pulmonary function test results also improved as follows: VC, 2.43 L; %VC, 110.0%; FEV
1, 1.79 L; FEV
1%, 69.38%; and PEF 4.16 L/s.