title: Active surveillance is suitable for intermediate term follow-up of renal oncocytoma diagnosed by percutaneous core biopsy.
abstract: OBJECTIVE
  To evaluate the intermediate outcome of conservative management in patients with biopsy-proven oncocytoma.
  
  
  METHODS
  Patients with oncocytoma diagnosed on percutaneous core biopsy between January 2000 to December 2014 were identified from the renal biopsy database of a large specialist urologic pathology laboratory. After review of patient clinical records, the study cohort comprised only of patients enrolled in active surveillance. Clinicopathological and follow-up details were reviewed for each case, in particular: type and interval of surveillance imaging, tumour growth, definitive intervention and reason for intervention. Where possible, correlation was made between the final surgical and the initial biopsy specimens.
  
  
  RESULTS
  Fifty three patients diagnosed with oncocytoma on core biopsy were initially placed on active surveillance with median follow-up of 34 months (range 6-109). The median age at diagnosis was 65 years (range 20-85) and median tumour size was 30 mm (range 13-87). Mean average tumour growth was 1.4 mm per annum (median 0 mm/year) with the majority (36 of 53, 68%) exhibiting minimal growth (less than 2 mm per annum) or partial regression. Forty seven of the 53 patients remained on active surveillance with no significant progression. Six patients elected to undergo definitive intervention (five surgical excision, one ablation). Renal oncocytoma was confirmed in all five patients who underwent surgical excision of their lesions.
  
  
  CONCLUSIONS
  The majority of oncocytomas in this study showed minimal growth rate or regression. Patients with biopsy proven oncocytoma can be conservatively managed with active surveillance.
authors.affiliation: Royal Perth Hospital, Perth, WA, Australia. shuo.mark.liu@hotmail.com.|Port Macquarie Base Hospital, Port Macquarie, NSW, Australia. shuo.mark.liu@hotmail.com.
authors.forename: Shuo
authors.initials: S
authors.lastname: Liu
authors.affiliation: Uropath Pty Ltd, West Leederville, WA, Australia.|Faculty of Medicine and Dentistry, School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, WA, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lee
authors.affiliation: Port Macquarie Base Hospital, Port Macquarie, NSW, Australia.|Faculty of Medicine, Rural Clinical School, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Prem
authors.initials: P
authors.lastname: Rashid
authors.affiliation: Royal Perth Hospital, Perth, WA, Australia.|Fiona Stanley Hospital, Perth, WA, Australia.
authors.forename: Haider
authors.initials: H
authors.lastname: Bangash
authors.affiliation: Royal Perth Hospital, Perth, WA, Australia.|Fiona Stanley Hospital, Perth, WA, Australia.
authors.forename: Akhlil
authors.initials: A
authors.lastname: Hamid
authors.affiliation: Uropath Pty Ltd, West Leederville, WA, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Lau
authors.affiliation: Uropath Pty Ltd, West Leederville, WA, Australia.|Faculty of Medicine and Dentistry, School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, WA, Australia.
authors.forename: Ronald
authors.initials: R
authors.lastname: Cohen
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D062005:Biopsy, Large-Core Needle; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D057832:Watchful Waiting; D055815:Young Adult
keywords: active surveillance; percutaneous biopsy; renal cell carcinoma; renal oncocytoma