Congenital Pulmonary Airway Malformation: 24 Cases from a Tertiary Referral Center.
Deepti M Reddi, Elizabeth N Pavlisko, James L Burchette, Thomas A Sporn, Victor L Roggli. Duke University Medical Center, Durham, NC
Background: Congenital pulmonary airway malformation (CPAM), formerly known as congenital cystic adenomatoid malformation (CCAM) is a rare congenital cystic pulmonary lesion, secondary to abnormal embryogenesis with anomalous lung and airway development. Several have hypothesized that CPAM subtypes originate at distinct stages of lung development with bronchiolar subtypes (CPAM types I to III) developing in the pseudoglandular stage and the acinar-alveolar subtype (CPAM type IV) occurring in late saccular period. Increased E-cadherin, which is regulated by HOXb5, is seen in CPAM lesions. Here we report, CPAM frequency and associated congenital anomalies in a tertiary referral center. We further hope to elucidate E-cadherin protein expression in specific CPAM types.
Design: With institutional approval, 24 cases (21 surgical; 3 autopsy) of CCAM/CPAM from 1993 to 2010 and age-matched controls were retrieved from our archives for clinicopathologic correlation. E-cadherin expression by immunohistochemistry was evaluated in representative cases from types I to III and compared to age-matched controls.
Results: Of 24 cases (13 male; 12 female) patient age at radiographic diagnosis ranged from 5.5 weeks gestation to 47 years; pathologic confirmation ranged from 24 weeks gestation to 47 years. Frequency of CPAM types I to III was 50%, 37.5% and 12.5%, respectively. The right lung was more often affected, with lower lobe predominance. Additional congenital anomalies were localized to the thoracic cavity and included extrapulmonary sequestration, bronchogenic cyst, diaphragmatic hernia and pulmonary hypoplasia. One case of bronchiolo-alveolar cell carcinoma arose from CPAM type I. In comparison to age-matched controls, E-cadherin protein expression, as qualified by immunohistochemistry, is uniformly strongly expressed in representative CPAM types I to III in comparison to controls.
Conclusions: The most common type of CPAM is type I. Although congenital anomalies, notably extrapulmonary manifestations, have been associated with type II, our cases show congenital anomalies in other types. Radiographic diagnosis of type I occurred as early as 5-6 weeks which indicates that the bronchiolar subtype may develop in or prior to the pseudoglandular stage. HOXb5 upregulation has been previously reported in CPAM without specification to type. Our series indicates increased E-cadherin protein expression via immunohistochemistry specifically in the bronchiolar subtype which may correlate with increased gene expression and upregulation of the HOXb5 pathway.
Monday, February 28, 2011 1:00 PM
Poster Session II # 197, Monday Afternoon