A 59-year-old man who appeared healthy without any underlying disease, visited our hospital with a cough and sputum that had persisted for more than a month. The patient had undergone chest computed tomography (CT) after abnormal findings on chest X-ray at another hospital. Based on the chest CT results, he was diagnosed with pneumonia in the right upper lobe and was admitted to that hospital. He was treated with intravenous injections of third-generation cephalosporin antibiotics for 3 weeks. However, after the treatment, there was no improvement in the lesion. Hence, he was transferred to our hospital. He had a 40-pack-years smoking history and no family history. He also had a working history of iron welding in the preceding 5 months.
He was alert, and the following findings were noted in the physical examinations upon admission: blood pressure, 140/70 mmHg; pulse rate, 85 beats per minute; respiratory rate, 20 breaths per minute; and body temperature, 36.8  C. He had a chronically ill appearance. His conjunctiva was not anemic and his sclera was not icteric. Clear breathing sounds were auscultated on both lung fields and his heartbeats were regular without murmur upon auscultation. The other examination results were also within normal limits. The following were the results of a laboratory examination: hemoglobin and hematocrit levels, normal; white blood cell count, 11,670/muL: differential count, 52.4% neutrophils, 31.7% lymphocytes, 12.5% monocytes, and 3.2% eosinophils; platelet count 292 x 109/L; C-reactive protein levels, slightly elevated at 32 mg/L (normal range 0-5 mg/L); serum ferritin levels, 151.4 mug/L (normal range 30-400 mug/L); serum transferrin saturation levels 31.1% (normal range 20-50% in males); and renal and liver function tests, normal. Arterial blood examination while breathing room air showed a blood pH of 7.44, a PaO2 of 71.0 mmHg, a PaCO2 of 36.7 mmHg, and HCO3 of 24.7 mM/L, with 96% oxygen saturation.
Pulmonary function studies revealed results within a normal range. Forced vital capacity (FVC) of 4.19 liters (96% of predicted) and forced expiratory volume-one second (FEV1) of 3.16 liters (102% of predicted) were observed. To examine the possible source of infection, he underwent recurrent sputum analysis. However, the bacterial, viral, fungal and acid fast bacilli cultures from sputum were all negative.
Three months before admission, he had undergone a chest X-ray at our hospital. At that time, his chest X-ray showed normal images. When he was admitted, his chest X-ray showed a pattern of consolidation in the right upper lung field (Fig. 1). A CT scan of the chest showed peribronchial distribution with peripheral segmental air-space consolidation in the right upper posterior segment, and small ill-defined nodules. It also showed centrilobular emphysema in both the upper and mid-lung zones. The air space consolidation on right upper lung field was increased compared with previous study results (Fig. 2).
Bronchoscopy was performed 3 days after admission and there was no endobronchial lesion observed. Bronchial washing was performed in the right upper lobe and bronchoalveolar lavage (BAL) was performed in the right middle lobe. Retrieved lavage fluid volume was 60ml (31%). Cytospin examination showed 4% neutrophils, 6% lymphocytes, 88% alveolar cells, and 2% eosinophils. Photomicrographic findings after bronchoalveolar lavage revealed many alveolar macrophage-containing iron particles. The intracellular iron particles were markedly positive upon Prussian blue staining (x 1000) (Fig. 3). Moreover, no malignant cells were observed. Acid-fast bacilli cultures and smears, tuberculosis detection PCR, bacterial detection Gram stain and cultures, and bronchoalveolar lavage fluid fungus cultures also presented negative results.
We did not measure the ferritin levels in bronchoalveolar lavage fluid. CT-guided trans thoracic needle biopsy was performed for histological confirmation. The biopsy specimen also showed alveolar, macrophage-containing, Prussian blue-positive iron particles in the alveolar space (Fig. 4). No evidence of vasculitis and malignancy was observed in the histological examination. Serum ANCA levels were also measured and confirmed to be negative. Based on the patient's occupational exposure history and test results, the diagnosis of pulmonary siderosis (welder's lungs) was confirmed.
Subsequently, we advised him to discontinue his job and discharged him from the hospital. No specific treatment was administered and only medications to control symptoms were prescribed. One month later, we performed bronchoalveolar lavage again. Two months later, a chest X-ray was performed in the outpatient clinic. The consolidation lesion observed in the right upper lobe had slightly improved (Fig. 1). The patient is currently undergoing observation, and has not shown any special symptoms.