title: Bilateral testicular microlithiasis predicts the presence of the precursor of testicular germ cell tumors in subfertile men.
abstract: OBJECTIVE
  A high prevalence of testicular microlithiasis has been described in adolescent and adult clinical cases of invasive testicular germ cell tumor (TGCT), that is seminomas and nonseminomas. However, to our knowledge it remains to be established whether testicular microlithiasis also indicates the presence of the pre-invasive lesion of this cancer, known as carcinoma in situ (CIS). We determined the predictive value of unilateral and bilateral testicular microlithiasis for CIS in subfertile men, a known risk population for TGCTs (approximately 1%).
  
  
  METHODS
  In a retrospective cross-sectional study the association between testicular microlithiasis and CIS was studied in a group of 263 men referred for subfertility. Testicular microlithiasis and CIS were diagnosed in all men by scrotal ultrasound and in testicular histology specimens as part of the routine evaluation of all patients.
  
  
  RESULTS
  Of the 263 subfertile men 53 (20%) had testicular microlithiasis. No CIS or TGCT was identified in the 23 men with unilateral testicular microlithiasis. In contrast, 6 of the 30 men (20%) with bilateral testicular microlithiasis were diagnosed with CIS. Therefore, the prevalence of CIS in subfertile men with bilateral testicular microlithiasis is significantly higher than in patients without testicular microlithiasis (1 of 210, 0.5%) and with unilateral testicular microlithiasis (0 of 23, 0%) (p <0.0001).
  
  
  CONCLUSIONS
  Bilateral testicular microlithiasis is indicative for CIS in subfertile men. Since these men are at particular risk for invasive TGCT, an assessment of testicular microlithiasis is a valuable tool for the early diagnosis of this disease.
authors.affiliation: Department of Andrology, and Laboratory for Experimental Pathology, Josephine Nefkens Institute, Erasmus Medical Center-University Medical Center Rotterdam, The Netherlands. c.degouveiabrazao@erasmusmc.nl
authors.forename: C A
authors.initials: CA
authors.lastname: de Gouveia Brazao
authors.forename: F H
authors.initials: FH
authors.lastname: Pierik
authors.forename: J W
authors.initials: JW
authors.lastname: Oosterhuis
authors.forename: G R
authors.initials: GR
authors.lastname: Dohle
authors.forename: L H J
authors.initials: LH
authors.lastname: Looijenga
authors.forename: R F A
authors.initials: RF
authors.lastname: Weber
mesh_terms: D000328:Adult; D001706:Biopsy; D002137:Calculi / Q000150:complications / Q000473:pathology*; D002278:Carcinoma in Situ / Q000473:pathology*; D003430:Cross-Sectional Studies; D003456:Cryptorchidism / Q000150:complications; D018237:Germinoma / Q000473:pathology; D006801:Humans; D007248:Infertility, Male / Q000150:complications; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions; D011379:Prognosis; D012189:Retrospective Studies; D013733:Testicular Diseases / Q000150:complications / Q000473:pathology*; D013736:Testicular Neoplasms / Q000473:pathology*; D014646:Varicocele / Q000150:complications