CD10 and CD34 as markers in vascular malformations with PIK3CA and TEK mutations: Immunohistochemical Profile in Vascular Anomalies.

AIMS: Vascular malformations (vMs) encompass a wide range of diseases often associated with somatic or, more rarely, germinal genetic mutations. A mutation in the PIK3Ca/mTOR pathway is more often involved in various vMs. CD10 and CD34 are cellular markers that may play a role in mesenchymal differentiation and proliferation. The aim of our study was to find a possible link between the immunohistochemical expression of CD10 and CD34 in vMs and their relationship with mutations in the PIK3CA/mTOR signaling pathway. METHODS AND RESULTS: Our study on 58 samples of vMS showed that in endothelial cells CD10 was significantly expressed in PIK3CA mutated samples compared to samples without any mutation (p<0.05), especially and even more consistently when compared to samples with mutation in other pathways (p <0.0001). Conversely, in the same PIK3CA mutated samples, CD34 expression in endothelial cells was significantly reduced compared to samples either without any mutation or mutations in other pathways (p<0.05 and p<0.0005). Compared to samples with mutations in other pathways a significant overexpression of endothelial CD10 was also found in samples with TEK/TIE2 mutation, a gene linked to the PIK3CA/mTOR pathway (p<0.01). However, CD34 expression was not altered. In samples with PIK3CA mutation, the CD10 expression was significantly increased in the stroma as compared to samples with TEK/TIE2 gene or other genes mutations (p<0.05). CONCLUSION: Therefore, CD10 and CD34 immunohistochemical profile could suggest/support the presence of mutations in PIK3CA/mTOR pathway in samples of vMs.