857 Congenital Pulmonary Airway Malformation: A Case Report of Concealed Malignancy

Introduction

Congenital pulmonary airway malformation (CPAM) is a developmental disorder in which hamartomatous lesions arise in the lower respiratory tract. Large population data suggests the incidence to be between 0.87 and 1.92/10,000 live births. Adults most often present with persistent cough or recurrent LRTIs. Their rarity can lead to misdiagnosis as a cystic lesion.

Surgery is the intervention of choice for symptomatic patients. The role of expectant management in asymptomatic patients remains controversial. In adults, resection may be favoured as these lesions are prone to infection and malignancy develops in approximately 1%.

Method

We present the case of a 44-year-old woman, with shortness of breath and pleuritic chest pain. CT revealed a 9.7 x 5.4cm lucent lesion in the left lower lobe, initially identified as a large bulla or parenchymal cyst. Decision to resect was made post discussion with the patient, who was keen to proceed to surgery, due to ongoing symptoms.

Results

A left lower lobectomy was performed via VATS. She was discharged on post-operative day 6, made an excellent recovery on 6-week follow-up and has entered surveillance. Histopathology revealed that the cyst was partially lined with respiratory epithelium and palisading histiocytes; favouring a CPAM type 1 diagnosis. Microscopically, there were foci of mucinous lepidic adenocarcinoma.

Conclusions

It is important to consider CPAM in the differential for cystic lung diseases. Surgical resection should be considered for CPAM regardless of symptoms, due to the uncertainty in diagnosis from imaging alone and the potential for malignant change.