title: [Intra-scrotal lithiasis. Crystallographic analysis].
abstract: OBJECTIVE
  To present two cases of intrascrotal lithiasis associated with hydrocele and the results of the crystallographic study.
  
  
  METHODS
  Three intrascrotal calculi in two patients aged 72 and 75 years that underwent surgery for hydrocele were analyzed. Two 2-mm. calculi were incidentally discovered during surgery for a right hydrocele in one patient. An ultrasound scan of the other patient showed a left hydrocele with a free-floating, round, hyperechoic, 6-mm. calculus, with posterior acoustic shadow. None of the patients had a previous history of trauma. The 3 calculi were white and smooth, but turned yellow and rough after removal. Scanning electron microscopy and x-ray dispersion studies were performed.
  
  
  RESULTS
  All 3 calculi had a center comprised of hydroxyapatite and white organic matter, and an exterior of yellow organic matter. The mineral portion of the center of the 6-mm. calculus and one of the 2-mm. calculi was composed of 33% phosphorus and 67% calcium, and the other 2-mm. calculus contained 32% phosphorus and 68% calcium by x-ray dispersion analysis.
  
  
  CONCLUSIONS
  Intrascrotal lithiasis is rare. In the two cases described herein, we observed abundant organic matter, particularly on the stone surface, and hydroxyapatite, particularly in the center. Among the possible etiologic causes, the deposit of organic matter in the presence of high oversaturation of calcium phosphates and absence of crystallization inhibitors, can initiate calcification and the subsequent collection of organic matter makes the process irreversible.
authors.affiliation: Servicio de Urología, Hospital del Bierzo, La Coruña, España.
authors.forename: José María
authors.initials: JM
authors.lastname: Sánchez Merino
authors.forename: Alberto
authors.initials: A
authors.lastname: Lancina Martín
authors.forename: Félix
authors.initials: F
authors.lastname: Grases Freixedas
authors.forename: Luis
authors.initials: L
authors.lastname: Parra Muntaner
authors.forename: Sergio Carlos
authors.initials: SC
authors.lastname: Gómez Cisneros
authors.forename: Jesús
authors.initials: J
authors.lastname: García Alonso
mesh_terms: D000368:Aged; D018360:Crystallography, X-Ray; D017886:Durapatite / Q000032:analysis*; D006801:Humans; D020347:Lithiasis / Q000737:chemistry* / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D008297:Male; D008855:Microscopy, Electron, Scanning; D009930:Organic Chemicals / Q000032:analysis; D012611:Scrotum / Q000000981:diagnostic imaging / Q000601:surgery; D006848:Testicular Hydrocele / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D014463:Ultrasonography
chemical_list: D009930:Organic Chemicals; D017886:Durapatite