title: Advances in the diagnosis of gestational trophoblastic tumors and tumor-like lesions.
abstract: BACKGROUND
  Gestational trophoblastic tumors and tumor-like lesions are derived from trophoblastic cells and are composed of different trophoblastic subpopulations. Recent histopathological and molecular studies indicate that these trophoblast-related lesions recapitulate the differentiation of normal trophoblast in early placenta development.
  
  
  OBJECTIVE
  To distinguish trophoblastic tumors from other types of neoplastic disease and differential diagnosis among different types of trophoblastic lesion are important as far as treatment plans are concerned.
  
  
  METHODS
  This article reviews the histopathological features of these trophoblastic lesions and recent advances in the trophoblast-associated markers, which are helpful in differential diagnosis.
  
  
  CONCLUSIONS
  Histopathologic features serve as the basis in the diagnosis of various types of trophoblastic lesion. In difficult cases, a stepwise immunohistochemistry approach, called trophogram, may prove useful in assisting the differential diagnosis.
authors.affiliation: National Taiwan University, Pathology, Taipei, Taiwan.
authors.forename: Tsui-Lien
authors.initials: TL
authors.lastname: Mao
authors.forename: Ie-Ming
authors.initials: IeM
authors.lastname: Shih