The glandular component in congenital cystic adenomatoid malformation of the lung

Abstract

Although severe congenital cystic changes (CCC) of the lung may be fatal, less severe forms may regress or vanish spontaneously. With recent advances in sonography, asymptomatic CCC are increasingly found. Whether all CCC should be promptly excised, or not, is uncertain. Congenital cystic changes conceptually are bronchopulmonary foregut malformations (BPFM) with a predilection for malignant degeneration. Among all BPFM, congenital cystic adenomatoid malformation (CCAM) is most common. We therefore searched for evidence of early malignant transformation in five surgically excised and three autopsy lungs with CCAM. By light microscopy, CCAM resembled poorly formed and dilated bronchi, bronchioles and respiratory air spaces. Four lungs had multiple nodular aggregates of mucus producing cells; the glandular component (GC). By scanning electron microscopy, GC appeared as multiple micropolyps, resembling neuroepithelial bodies. By transmission electron microscopy, GC had a surface proliferation of cells with granules of the mucous type and a basal increase in cells with owl-eyed neuroendocrine granules. The glandular component in CCAM appeared similar to the mucous cells in hyperplastic polyps of the colon and a type of mucus producing bronchioloalveolar carcinoma. Our findings support the hypothesis that CCAM is caused by dysregulated paracrine growth of mature cells and extracellular matrices and that GC could have the potential for malignant transformation. Further clinical and laboratory studies of BPFM are needed for the appropriate management of congenital cystic changes.

Bronchioloalveolar carcinoma arising in a congenital pulmonary airway malformation in a child: case report with an update of this association

“…Type 1 lesions are the most common, accounting for 60% to 70% of all cases and hitherto have been only eventually associated with mucinous BAC [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The clusters of mucogenic cells, present in 35% to 50% of type 1 CPAMs [14] and rarely reported on type 2 CPAMs [15], have been implicated in malignant transformation [11,16,17]. In addition, to exhibit a morphogenetic pattern similar to colonic hyperplastic polyps, which can evolve into dysplastic lesions and adenocarcinoma (AC) [16], chromosomal aberrations have been described in areas of AGCH giving support to their preneoplastic status [17].…”

“…The clusters of mucogenic cells, present in 35% to 50% of type 1 CPAMs [14] and rarely reported on type 2 CPAMs [15], have been implicated in malignant transformation [11,16,17]. In addition, to exhibit a morphogenetic pattern similar to colonic hyperplastic polyps, which can evolve into dysplastic lesions and adenocarcinoma (AC) [16], chromosomal aberrations have been described in areas of AGCH giving support to their preneoplastic status [17]. However, the incidence of carcinoma is less than 1% [12,13,17], and the only evidence that these lesions represent true malignancies is the rare incidence of metastatic spread [9,12,13].…”

Bronchopulmonary foregut malformations: embryology, radiology and quandary

“…The BC have been associated with bronchogenic carcinoma in adults [62]. Wang et al identified glandular tissue, similar to adenomatous polyps and bronchoalveolar carcinoma within CCAM [1], and Cass et al found increased cell proliferation and decreased apoptosis within CCAM [2] suggesting the possibility for premalignant change in BPFM. Conran and Stocker [3] identified rhabdomyomatous degeneration in 48% of combined ELS/CCAM lesions that they examined.…”

“…Improvements in fetal intervention and surgery, combined with a desire to reduce the number of terminations in affected fetuses, have necessarily led to further consideration of the antenatal progress and prognosis of cystic lung lesions. In addition, several authors have reported cases of malignancy that appeared to arise from congenital cystic lung lesions [1,2,3,4,5,6]. The radiological diagnosis and assessment of these lesions has therefore become ever more important.…”

Squamous metaplasia in the cyst epithelium of type 1 congenital pulmonary airway malformation after thoracoamniotic shunt placement

“…It has been reported that tufts of mucigenic cells exist on the surface on large cysts or within the smaller bronchiolar-like structures adjacent to the larger cysts in about 35% of type 1 CPAM cases [2]. Past reports indicate that these cells are involved with the occurrence of bronchioloalveolar carcinoma in both older patients with type 1 CPAM and patients who have had a type 1 CPAM removed in infancy [8][9][10][11][12][13].…”