Cystic and pseudocystic pulmonary malformations in children: Clinico-pathological correlation.

Pulmonary malformations are rare disorders, with cystic and pseudocystic pulmonary malformations (CPPM) the most frequent, and constitute the first cause of lobectomy in children <1 year of age. Morphological overlap of congenital cystic pulmonary lesions might correspond to a spectrum of lesions in which bronchial atresia is a common etiopathogenetic mechanism. We aimed to report the frequency of CPPM resected in a tertiary-level hospital and to evaluate the degree of agreement between presurgical and anatomopathological diagnoses. We studied 44 surgical pieces with a diagnosis of CPPM received at the Pathology Service from 2009 to 2014, resected from 39 patients, 51.3 % males, with a median age of 16.8 months. Up to 69.2% of the patients had adenomatoid malformation of pulmonary airway (AMPA), with type 2 the most frequent (55.5%). Pulmonary sequestration was present in 15.4% of patients; in two cases the diagnosis was an incidental finding during surgery for the repair of a diaphragmatic hernia. Congenital lobar hyperinflation (CLH) occurred in 7.6% cases. Bronchogenic cyst (BC) was present in 7.6% cases. Presurgical and anatomopathological diagnoses in all patients coincided in 71.8% of cases. Kappa coefficient was 0.56 for global concordance in patients with AMPA, and 0.72, 0.64, 0.37 and 0.33 for CLH, BC, and types 1 and 2 AMPA, respectively. This relatively low interobserver agreement could reflect the low reproducibility of diagnoses used in the current nomenclature. Thus, the new nomenclature must be promoted in order to allow for better reproducibility and greater clinico-pathological concordance. The anatomopathological analysis must include the intentional search for bronchial atresia.