BACKGROUNDSo-called pulmonary sclerosing hemangioma (PSH) is a rare kind of pulmonary tumor. Its histological origin and nature, which have become research hot spots for many years, are still uncertain. The aim of this study is to investigate the immunophenotype of cuboidal cells and polygonal cells through observing the expression of E-cadherin, β-catenin and p120ctn in cuboidal cells and polygonal cells of PSH.

METHODSExpression of E-cadherin, β-catenin and p120 ctn was detected in 25 cases of PSH samples and 8 cases of pulmonary inflammatory pseudotumor samples by immunohistochemistry.

RESULTSImmunohistochemistry results showed that the surface cuboidal cells of PSH were strongly positive on membrane for E-cadherin, β-catenin and p120 ctn , with cytoplasmic positive expression of β-catenin. However,the polygonal cells were negative for E-cadherin, cytoplasmic positive for β-catenin and predominantly cytoplasmic positive and weakly membranous positive for p120ctn . In polygonal cells, all the three adhesion molecules showed heterogenicity staining. The cytoplasm and membrane of inner covering cells in the hemorrhagic pattern were positively stained for E-cadherin, β-catenin and p120ctn . The expression of the three adhesion molecules in hyperplastic type II alveolar cells of pulmonary inflammatory pseudotumor was similar to cuboidal cells of PSH.

CONCLUSIONSIt is concluded that cuboidal cells of PSH may be the hyperplastic type II alveolar cells, whereas polygonal cells are true tumor cells lacking the E-cadherin/catenin complex which is expressed in well differentiated epithelial cells. The inner covering cells in the hemorrhagic pattern of PSH are perhaps epithelial cells as cuboidal cells rather than vascular endothelial cells.