Delayed Diagnosis of Small Cell Lung Cancer in a Patient with Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity disorder induced by Aspergillus fumigatus that occurs generally in patients with underlying chronic airway disorders. However, the development of ABPA associated with lung malignancy remains unknown. An 80-year-old woman was admitted for evaluation of chronic cough. Her radiologic finding was a mass like opacity with mucoid impaction, showing finger-in-glove sign, one of the typical radiologic findings for ABPA. In addition, laboratory tests revealed that her data satisfied the diagnostic criteria for ABPA. Interestingly, final pathologic examination showed that the mass lesion was small cell lung cancer. Here, we describe a case of delayed diagnosis of small cell lung cancer with ABPA, suggesting that a possibility of accompanying lung malignancy such as small cell lung cancer should be considered in patients with ABPA. This case let us realize the importance of clinical suspicion that different entities of diseases can be occurred simultaneously for the correct diagnosis without delay.