Congenital cystic adenomatoid malformation type I

Abstract

Congenital cystic adenomatoid malformation (CCAM) is an hamartomatous congenital pulmonary airway malformation with incidence ranging between 1:10,000 and 1:35,000 newborns. Currently CCAM is classified into five groups according to clinical and pathological features. The clinical outcome varies depending on the subtype and the extent of involvement. The authors report the case of a premature male newborn with the prenatal diagnosis of CCAM Type 1 associated with cardiac right axis deviation, who died 67 hours after birth due to respiratory failure. In addition to the autopsy report of this rare entity, the authors present its classification and prognosis.

Keywords: Autopsy; Classification; Cystic Adenomatoid Malformation of Lung, Congenital; Prognosis.

Figure 1. A – Monoblock’s anterior view showing the bulky mass that occupied the whole left hemithorax, slightly displacing the mediastinum to the right side; B – Posterior view of the monoblock depicting the mass; C – Involvement of the left inferior pulmonary lobe compressing the right lung; D – Gross appearance of the left inferior pulmonary lobe with multiple varying-sized cystic lesions.

Figure 2. Photomicrography of the pulmonary mass. A – Low magnification appearance of adenomatoid cystic malformation type 1: multiples varying-sized bronchiole-like cysts in a typical back-to-back conformation (HE 100X); B – Cysts lined by pseudostratified and cuboidal to tall columnar epithelial cells with a thin fibrovascular layer (HE 200X); C – Island of mucogenic epithelium (HE 200X); D – High magnification showing mucinous cells resembling pyloric mucosa (HE 400X).

Figure 3. Photomicrography of the lung. A – The transition between the tumor mass and left upper pulmonary lobe (HE 100X); B – Inferior right pulmonary lobe showing hyaline membrane (HE 100X).