C44-14 Pulmonary Sequestration and Aspergillus: Two Cases Mimicking Malignancy in Asymptomatic Adults

Introduction Pulmonary sequestration is a rare congenital bronchopulmonary malformation characterized by nonfunctional lung parenchyma that lacks normal communication with the tracheobronchial tree and receives its blood supply from the systemic circulation. Most sequestrations are diagnosed in childhood due to recurrent bacterial infections, making adult cases uncommon. Diagnoses are often incidental or discovered from workup for other pathologies. We present a case series of two asymptomatic women found to have a right lower lobe (RLL) pulmonary mass initially suspected to be malignant but diagnosed with Aspergillus as a unique presentation and avenue of diagnosing pulmonary sequestration. Case Series Case 1 is a 54yo female who was referred for evaluation of an incidentally discovered RLL mass (5.8 x 4.3 x 4.4 cm) on full-body screening MRI. Bronchoscopy with EBUS revealed acute inflammation, necrotic debris, and fungal hyphae. Bronchoalveolar lavage galactomannan was positive for Aspergillus, and the patient was started on voriconazole. Follow up CT chest revealed that the RLL mass (5.9 cm) is supplied by a systemic arterial vessel without normal bronchial communications, confirming intralobar sequestration (figure 1a). The patient underwent a successful robotic RLL wedge resection and was discharged on post-operative day one. Case 2 is a 77yo female with a history of breast cancer who had an incidental RLL mass (5.8 cm x 4.5 cm) found on CT when she was 72yo. Bronchoscopy with biopsy at that time showed neutrophilic debris, acute on chronic inflammation, macrophages, fungal organisms, and rare reactive bronchial cells. Galactomannan was within normal limits. Given pathologic findings, she was treated empirically with voriconazole. Follow-up imaging showed a slightly larger RLL mass (6.4 cm x 5.4 cm) (figure 1b) but she remained asymptomatic, so shared decision making opted for interval surveillance. Discussion With over 1.5 million chest CT scans being performed annually in the United States, providers are frequently tasked with risk stratifying incidental findings. This case series highlights two cases of incidentally found pulmonary sequestration, a rare phenomenon in adults. Aspergillus is often diagnosed post-operatively after surgical resection. To our knowledge, these cases are the first to highlight the diagnostic pathway of incidental identification of a pulmonary mass with nonsurgical diagnosis of Aspergillus and subsequently pulmonary sequestration. Providers should be wary of an Aspergillus diagnosis in large lesions with atypical presentation, maintain a high suspicion for sequestration, and refer to thoracic surgery for definitive management. This abstract is funded by: None