Abstract
Because of the histopathological similarity, histological differentiation between basal cell carcinoma (BCC) and trichoblastoma (TB) can be difficult. Recent investigations show that constitutive activation of the patched (PTC) -hedgehog signaling pathway plays an central role in the development of BCC. By contrast, TBs do not show either loss of heterozygosity (LOH) at the loci surrounding PTC gene or overexpression of PTC mRNA, suggesting that the deregulation of the PTC-hedgehog signaling pathway is not involved in the molecular pathogenesis of TB. These findings indicate that, although morphologically similar, TB and BCC have different molecular pathogenesis, and that molecular biological methods such as in situ hybridization for PTC mRNA would be useful in the differential diagnosis between TB and BCC. [Skin Cancer (Japan) 2002; 17: 21-25]
