Abstract

Background: Pulmonary sclerosing haemangioma (PSH) is an uncommon tumour that is composed of glandular/papillary lining cells and polygonal cells. The biological behaviour of this tumour has been investigated; however, the molecular pathogenesis of PSH remains unknown.

Aims: To characterise the role of the Wnt/β-catenin pathway in the genesis of PSH.

Methods: 37 PSH samples were investigated immunohistochemically for detection of the β-catenin protein and direct sequencing of exon 3 of the β-catenin gene.

Results: Nuclear expression of β-catenin was found in the lining component of 23 tumours (62%) and in the polygonal component of 11 tumours (30%). The expression of β-catenin was stronger in the lining component, but weaker in the polygonal component. Interestingly, all the tumours with expression of β-catenin in the polygonal component also expressed β-catenin in the lining component. However, mutation of exon 3 of the β-catenin gene was detected in only one tumour that expressed nuclear β-catenin in lining and polygonal components.

Conclusions: The Wnt/β-catenin pathway is involved in the genesis of PSH, but mutation of exon 3 of the β-catenin gene rarely contributes to the activation of the Wnt/β-catenin pathway in PSH.