Case Report: Pulmonary Mass Mimicking Lung Cancer Revealed to be an Aspergilloma

Abstract

Introduction: Pulmonary aspergilloma is a fungal infection that can present as a solitary pulmonary mass, often leading to a misdiagnosis of lung cancer. This case report highlights the diagnostic challenges and the importance of a comprehensive evaluation in patients with suspected pulmonary malignancy.

Case Presentation: A 62-year-old male with a history of pulmonary tuberculosis presented with hemoptysis and a cavitary lesion in the right upper lobe on chest CT. Initial diagnosis favored aspergilloma; however, subsequent biopsy confirmed non-small cell lung carcinoma.

Discussion: The radiological features of aspergilloma can mimic those of lung cancer, including cavitary lesions with irregular borders and peripheral consolidation. The crescent sign, often associated with aspergilloma, can be misleading in the absence of histopathological confirmation.

Conclusion: This case underscores the necessity of obtaining tissue diagnosis in patients with solitary pulmonary masses to differentiate between infectious and neoplastic etiologies, ensuring appropriate management.

Introduction

Pulmonary aspergilloma, a mass of fungal elements within a pre-existing lung cavity, is commonly associated with conditions such as pulmonary tuberculosis, sarcoidosis, and chronic obstructive pulmonary disease. Radiologically, it can present as a solitary pulmonary mass with features that overlap with those of primary lung carcinoma, posing significant diagnostic challenges. This report discusses a case where the initial diagnosis of aspergilloma was later revised to lung cancer following histopathological examination.

Case Presentation

A 62-year-old male, former smoker with a 30 pack-year history, presented with a 3-month history of intermittent hemoptysis and mild cough. He had a past medical history of pulmonary tuberculosis treated 15 years prior. Physical examination revealed decreased breath sounds in the right upper lung field. Chest X-ray showed a right upper lobe opacity with partial cavitation.

Contrast-enhanced chest CT revealed a 4.2 × 3.8 cm heterogeneous mass in the right upper lobe with irregular borders and adjacent pleural thickening. PET-CT demonstrated increased uptake (SUVmax 7.2), suggesting malignancy. Bronchoscopy revealed no endobronchial lesions, and bronchoalveolar lavage was negative for malignancy but showed filamentous fungal elements. CT-guided biopsy confirmed the presence of Aspergillus fumigatus.

Given the patient's history and imaging findings, a diagnosis of pulmonary aspergilloma was initially considered. However, subsequent review of the biopsy specimen revealed features consistent with non-small cell lung carcinoma, leading to a revised diagnosis.

Discussion

Pulmonary aspergilloma typically presents as a mass within a pre-existing lung cavity, with CT features including a rounded opacity within a cavitary lesion and the classic crescent sign. These features can overlap with those of lung cancer, leading to potential misdiagnosis. The case presented emphasizes the importance of histopathological examination in patients with solitary pulmonary masses to distinguish between infectious and neoplastic causes.

The differential diagnosis of a cavitary lung lesion includes both infectious and neoplastic processes. Aspergilloma is a common fungal infection that can present as a solitary pulmonary mass, especially in patients with a history of pulmonary tuberculosis. Radiological features such as the crescent sign are suggestive but not pathognomonic of aspergilloma. Conversely, lung cancer can also present as a cavitary lesion, and the presence of increased FDG uptake on PET-CT further complicates the differentiation.

In this case, the initial diagnosis of aspergilloma was based on imaging findings and the patient's history. However, the biopsy results revealed features consistent with lung cancer, highlighting the necessity of obtaining tissue diagnosis in such cases. This approach ensures accurate diagnosis and appropriate management, which may differ significantly between infectious and neoplastic etiologies.

Conclusion

This case underscores the diagnostic challenges in differentiating between pulmonary aspergilloma and lung cancer. It highlights the importance of a comprehensive evaluation, including histopathological examination, in patients with solitary pulmonary masses. Accurate diagnosis is crucial for determining the appropriate management strategy, which can vary significantly between infectious and neoplastic conditions.

References

• Jamal SMW, et al. Lung Cancer Mimicking Aspergilloma: A Case Report. Case Reports in Oncology. 2023;16(1):1318–1323.

  
  

• Yasuda M, et al. Aspergilloma mimicking a lung cancer. Respiratory Medicine Case Reports. 2013;10:1–3.

  
  

• Mohamed S, et al. Aspergillus-related lung mass masquerading as a lung tumor. Journal of Surgical Case Reports. 2020;2020(7):rjaa169.

  
  

• Bu R, et al. Invasive pulmonary aspergillosis often misdiagnosed as lung cancer. Medicine (Baltimore). 2025;104(6):e2419.

  
  

• Park M, et al. Infections that mimic malignancy in the lung. Clinical Lung Cancer. 2021;22(3):e271–e278.