Vol.:(0123456789) 1 3 Pediatr Surg Int DOI 10.1007/s00383-017-4206-0 REVIEW ARTICLE Presence of viable germ cells in testicular regression syndrome remnants: Is routine excision indicated? A systematic review Ramesh Mark Nataraja 1,2  · Evie Yeap 1  · Costa J. Healy 3  · Inderpal S. Nandhra 3  · Feilim L. Murphy 4  · John M. Hutson 5,6  · Chris Kimber 1,2   Accepted: 24 October 2017 © Springer-Verlag GmbH Germany 2017 parameters and terms. Strict inclusion and exclusion crite- ria were ultilised to identify articles relevant to the review questions. Twenty-nine paediatric studies with a total of 1455 specimens were included in the systematic review. The mean age of the patients undergoing nubbin resection was 33 months and the TRS specimen was more commonly excised from the left (68%). The incidence of SNTs was 10.7% (156/1455) and the incidence of GCs, 5.3% (77/1455). His- tological analysis excluding the presence of either SNTs or GCs was consistent with TRS, fibrosis, calcification or haemosiderin deposits. There is limited evidence on sub- set analysis that GCs and SNTs may persist with increasing patient age. This systematic review has identified that 1 in 20 of resected testicular remnants has viable GCs and 1 in 10 has SNTs present. There is insufficiently strong evidence for the persistence of GCs and SNTs with time or future malig- nant potential. Intra-abdominal TRS specimens may contain more elements and, therefore, require excision, although this is based on limited evidence. However, there is no available strong evidence to determine that a TRS specimen requires routine excision in an inguinal or scrotal position. Keywords Testicular remnants · Testicular regression syndrome · Testicular nubbin · Undescended testicles · Cryptotorchism · Monorchidism Introduction Undescended testicles are a common finding in paediatric patients, 3% of full-term male infants at birth and 0.8% of males at one year of age. Of these patients, 20% are found to be clinically impalpable [1]. These impalpable testicles may be present within either the peritoneal cavity, inguinal canal, or an ectopic position. There may also only be a small Abstract There is no consensus in the literature about the necessity for excision of testicular remnants in the context of surgery for an impalpable testis and testicular regression syndrome (TRS). The incidence of germ cells (GCs) within these nubbins varies between 0 and 16% in previously pub- lished series. There is a hypothetical potential future malig- nancy risk, although there has been only one previously described isolated report of intratubular germ-cell neopla- sia. Our aim was to ascertain an accurate incidence of GCs and seminiferous tubules (SNTs) within excised nubbins and hence guide evidence-based practice. The systematic review protocol was designed according to the PRISMA guidelines, and subsequently published by the PROSPERO database after review (CRD42013006034). The primary out- come measure was the incidence of GCs and the secondary outcome was the incidence of SNTs. The comprehensive systematic review included articles published between 1980 and 2016 in all the relevant databases using specific search * Ramesh Mark Nataraja ram.nataraja@monashhealth.org 1 Department of Paediatric Surgery, Monash Children’s Hospital, 246 Clayton Road, Melbourne 3168, Australia 2 Department of Paediatrics, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia 3 Department of Paediatric Surgery, Barts Healthcare NHS Trust, London, UK 4 Department of Paediatric Surgery and Urology, St George’s Healthcare NHS Trust, Blackshaw Rd, London SW17 0QT, UK 5 Department of Paediatrics, University of Melbourne, Melbourne, Australia 6 F Douglas Stephens Surgical Research Laboratory, Murdoch Children’s Research Institute, Melbourne, Australia