A 58–year–old male patient, who had worked as a welder for 30 years, complained of 3 months history of progressively worsening hemoptysis. He underwent thoracotomy and right upper lobectomy 5 years ago for suspected malignant nodules but histopathology revealed welding related nodules. He had been an active smoker until 5 years ago. On examination, his vital signs were normal. Chest examination revealed no abnormalities except a scar of previous thoracotomy. The remainder of the examination was also within normal limits. His CXR showed a 1.5 cm multiform density nodular shadow in the right upper zone. CT chest showed ill–defined and solitary nodular shadow in the right upper lobe. Since it was extremely difficult to distinguish this lesion from malignant nodule based on just radiographic findings, a right sided thoracotomy and wedge resection of the right upper nodule was carried out. Histopathology revealed Aspergilloma with surrounding chronic granulomatous inflammation, fibrosis and sheets of macrophages having cytoplasmic iron pigment. The diagnosis of aspergilloma complicating pulmonary siderosis was made. Post operative course was uneventful and surgery resulted in resolution of his symptoms with no recurrence of his hemoptysis over 6 months follow up and has been well since.
Aspergilloma (fungus ball) is formed when aspergillus colonize and grow into a cavity and is typically seen in patients with a preexisting lung cavity from a variety of causes, such as pulmonary tuberculosis, lung cancer following treatment, COPD, fibrocavitary sarcoidosis, pneumatocele and pneumoconiosis. A typical radiologic finding of aspergilloma is a solid, round, or oval mass with soft–tissue opacity within a lung cavity, manifesting as “air crescent sign” which was absent in our case probably due to the limit of radiographic or CT resolution. Moreover, here in our case, we also describe a rare case of aspergilloma developed in pulmonary siderosis (welder’s lung). Pulmonary siderosis is a pneumoconiosis caused by chronic iron inhalation. A typical radiographic finding of pulmonary siderosis includes ill–defined, diffusely distributed centrilobular micronodules and rarely presents as a solitary nodule lesion like in our case. Because the radiographic findings were atypical, we conducted a thoracotomy and open wedge resection to exclude the diagnosis of lung neoplasm. After confirming iron deposition in the lung tissue, we concluded that this was an unusual case of pulmonary siderosis complicated by aspergilloma, and it can be manifested as a pulmonary irregular nodule mimicking lung neoplasm.
This case emphasizes the importance of practitioners recognizing the unusual presentation of pulmonary siderosis as a solitary nodule mimicking lung neoplasm which may expose the patients for unnecessary interventions. It also increases the awareness of the uncommon coexistence of aspergilloma with pulmonary siderosis.
Figure 1Computed Tomographic (CT) Scan of the Chest, lung window, shows 1.5 cm irrigular solitary nodular shadow in the right upper lobe (arrow).
Figure 2Wedge resection histopathology of the right lung nodule. Aspergilloma and pulmonary siderosis. A: Cavity containing pale–staining proliferating fungal hyphae (fungal ball) with iron staining in adjacent fibrous scar (Prussian blue iron stain, 100×). B: Dense interstitial fibrosis containing clusters and sheets of macrophages with cytoplasmic bright blue iron pigment (Prussian blue iron stain, 200×). C: Aspergillus f. fungal ball with clusters of fungal hyphae (GMS stain, 400×). D: Aspergillus fumigatus with classic fruiting head. (GMS stain, 630×).