Correct!
Answer: 3. Congenital bronchial atresia
Differential Diagnosis: The differential diagnostic “gamut” for this case is that of the solitary pulmonary nodule (SPN). The differential diagnosis for an SPN is large, but the most common causes of an SPN include primary pulmonary malignancy (both bronchogenic carcinoma and carcinoid tumors), solitary metastases, and infections (typically granulomas). Other lesions that may present as an SPN on chest radiography include hamartoma, arteriovenous malformation, mucoid impaction of a bronchus (common with congenital bronchial atresia), round atelectasis, artifacts and abnormalities external to the lug (such as skin lesions), pleural abnormalities (particularly loculated pleural fluid or pleural plaques), among numerous other potential etiologies.
References