title: [Clinicopathological study of intermediate trophoblastic non-tumor lesions: exaggerated placental site and placental site nodule].
abstract: OBJECTIVE
  To investigate the clinicopathological features of intermediate trophoblastic non-tumor lesions, and to evaluate the position of immunohistochemistry in differential diagnoses.
  
  
  METHODS
  Clinical presentation and morphological study of 15 cases of exaggerated placental site (EPS) and 4 cases of placental site nodule or plaque (PSNP) were reviewed. Immunohistochemical stains for hCG, hPL, inhibin-alpha, PLAP, CK18 and Ki-67 were performed.
  
  
  RESULTS
  The age of patients ranged from 25 to 40 years with an average of 31.5 years for EPS and 26 to 39 years with an average of 34.3 years for PSNP. Microscopically, EPS was characterized by cords and small sheets of implantation site intermediate trophoblasts infiltrating the endometrium, myometrium and arterial walls. The general histological structures of the endometrium and myometrium were preserved. PSNP was characterized by multiple circumscribed nodular lesions consisting of so-called chorionic-type intermediate trophoblasts and hyaline-like matrix present in the endometrium. Immunohistochemical stainings for hPL and CK18 were positive in the 15 EPS cases. Immunoreactivity for CK18, Inhibin-alpha and PLAP was detected in 4 PSNP cases. The Ki-67 labeling index in 15 EPS cases was low (< or = 5%), while Ki-67 index in 4 PSNP cases was close to 0.
  
  
  CONCLUSIONS
  The clinical presentation and pathological features of EPS and PSNP differ from those of trophoblastic tumors (placental site trophoblastic tumor, epithelioid trophoblastic tumor and choriocarcinoma). Immunochemical staining is of great value in their differential diagnoses.
authors.affiliation: Department of Pathology, People's Hospital, Peking University, Beijing 100044, China. Shenpath@sohu.com
authors.forename: Dan-hua
authors.initials: DH
authors.lastname: Shen
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Liao
authors.forename: Yan-li
authors.initials: YL
authors.lastname: Liu
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: You-zhi
authors.initials: YZ
authors.lastname: Yu
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004717:Endometrium / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007044:Hysterectomy / Q000379:methods; D007265:Inhibins / Q000378:metabolism*; D007633:Keratins / Q000378:metabolism*; D009215:Myometrium / Q000473:pathology; D010920:Placenta / Q000378:metabolism / Q000473:pathology*; D010922:Placenta Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D010928:Placental Lactogen / Q000378:metabolism*; D011247:Pregnancy; D014328:Trophoblastic Neoplasms / Q000473:pathology; D018245:Trophoblastic Tumor, Placental Site / Q000473:pathology; D014327:Trophoblasts / Q000473:pathology; D014594:Uterine Neoplasms / Q000473:pathology
chemical_list: C094377:inhibin-alpha subunit; D007265:Inhibins; D007633:Keratins; D010928:Placental Lactogen