title: [Composition and morphology of stones in enlarged prostatic utricle].
abstract: OBJECTIVE
  To investigate the composition and morphology of the stones in the enlarged prostatic utricle (EPU).
  
  
  METHODS
  We took out 36 EPU stones from 11 patients by transurethral fenestration between 1992 and 2011, and analyzed the stones by scanning electron microscopy, x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIS).
  
  
  RESULTS
  Under the scanning electron microscope, all the EPU stones were constituted of many intensive minicrystals and amorphous matrix. XRD and FTIS revealed that all were hydroxyapatite crystal.
  
  
  CONCLUSIONS
  EPU stones belong to the category of prostatic pseudo-calculi, whose formation is ascribed not to the abnormal change of urine composition, but to the continuous secretion, absorption and concentration of EPU liquid and ablated epithelial cells from the EPU.
authors.affiliation: 1. Department of Urology, Nanjing BenQ Hospital, Nanjing, Jiangsu 210019, China.
authors.forename: Jiu-Ming
authors.initials: JM
authors.lastname: Li
authors.forename: Hong-Fei
authors.initials: HF
authors.lastname: Wu
authors.forename: Nai-Cen
authors.initials: NC
authors.lastname: Xu
authors.forename: He-Tong
authors.initials: HT
authors.lastname: Zhou
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Yu
authors.forename: Ning-Hong
authors.initials: NH
authors.lastname: Song
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
mesh_terms: D002137:Calculi / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry; D006801:Humans; D008297:Male; D011467:Prostate / Q000737:chemistry* / Q000473:pathology*; D011469:Prostatic Diseases / Q000473:pathology* / Q000503:physiopathology
chemical_list: D017886:Durapatite