Genetic alterations in pulmonary epithelioid hemangioendothelioma and epithelioid angiosarcoma

Epithelioid hemangioendothelioma (EHE) is a low-to-intermediate-grade vascular tumor that occurs in many organs, and epithelioid angiosarcoma (EA) is a subtype of angiosarcoma that is associated with high-grade malignancy. These two types of tumors have different forms of biological behavior. Pulmonary epithelioid hemangioendothelioma (PEH) and epithelioid angiosarcoma (PEA) are both very rare, and genetic studies on them are extremely limited. We examined and compared the cytogenetic characteristics of these two types of lung tumors in two patients utilizing the Array-Comparative Genomic Hybridization (Array-CGH) method. Considerable differences in the cytogenetic characteristics were observed between the two types of tumors. Small fragment gains (<10 MB) were dominant in PEH, whereas large fragment gains and deletions (>10 MB) were dominant in PEA. Some large fragment alterations, such as gains in chromosomes 19q and 19p, and deletions in chromosomes 9p and 13q, involved over half of a chromosome arm. PEH and PEA showed great cytogenetic differences; therefore, further genetic studies on these two types of tumors are warranted.