Renal Oncocytosis: Management and Clinical Outcomes

Abstract

Purpose Renal oncocytosis is an extremely rare pathological condition in which renal parenchyma is diffusely involved by numerous oncocytic nodules, in addition to showing a spectrum of other oncocytic changes. Our aim was to describe our experience with renal oncocytosis, focusing on management and outcomes. Materials and Methods Twenty patients with a final pathologic diagnosis of renal oncocytosis from July 1995 through June 2009 were included in the analysis. Patient demographics, intraoperative variables and postoperative outcomes are reported. Results The median age at nephrectomy was 71 years. Fifteen patients (75%) had bilateral disease. There were 23 operations performed on 20 patients. Thirteen (57%) were partial nephrectomies and 10 (43%) were radical nephrectomies. The median diameter of the dominant tumor mass was 4.1 cm (range 1–14.6). The most common dominant tumor histology was hybrid tumor between oncocytoma and chromophobe renal cell carcinoma in 13 of 23 specimens (57%), followed by chromophobe RCC in 6 (26%), oncocytoma in 3 (13%) and conventional RCC in 1 (4%). Ten patients (50%) had pre-existing chronic kidney disease before nephrectomy and 5 more developed CKD after surgery. After a median follow-up of 35 months, no patient developed metastatic disease. Conclusions Patients with renal oncocytosis usually present with multiple and bilateral renal nodules. Half of the patients had CKD at diagnosis and 25% developed new-onset of CKD. No patient developed distant metastatic disease during follow-up. Our management approach is to perform a partial nephrectomy when possible and then employ careful surveillance of the remaining renal masses.

Renal oncocytosis in a pediatric patient: Case report and review of the literature

“…However, 4-6% will have multifocal disease while 4% will have bilateral disease (4). Patients range in age from 10 to 94 years of age (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12), with most occurring in the seventh decade of life. Our 12 year old patient is one of the younger ones described to date.…”

“…Renal oncocytoma has traditionally been regarded as a benign neoplastic tumor; however, chromophobe renal cell carcinoma has been described within the same kidney (1,8,11). If possible, nephron sparing surgery should be undertaken.…”

“…Renal oncocytomas are epithelial tumors composed of oncocytes that are well differentiated, contain eosinophilic cells and are arranged in a tubular pattern (1). Specific genetic conditions, such as Birt-Hogg-Dube (BHD) and Von -Hippel-Lindau syndrome, can also be associated with renal oncocytosis (1).…”

“…Specific genetic conditions, such as Birt-Hogg-Dube (BHD) and Von -Hippel-Lindau syndrome, can also be associated with renal oncocytosis (1). However, very few paediatric cases of renal oncocytoma have been described (4)(5)(6)(7)(8).…”

Identification of immunohistochemical biomarkers that differentiate chromophobe renal cell carcinoma from renal oncocytoma through molecular profiling of renal tumours

“…Renal oncocytosis was first described in 1982 (Warfel and Eble 1982): multiple and bilateral oncocytic nodules and a spectrum of oncocytic changes are found diffusely throughout the renal parenchyma. A large series investigating renal oncocytosis revealed that hybrid development of RO and chRCC was most common (Adamy et al 2011). Hybrid oncocytic chromophobe tumours are tumours which display histological features of both chRCC and RO.…”