Review

Authors: Carlos Nicolau, Natalie Antunes, Blanca Paño...

The detection of a renal mass is a relatively frequent occurrence in the daily practice of any Radiology Department. The diagnostic approaches depend on whether the lesion is cystic or solid. Cystic lesions can be managed using the Bosniak classification, while management of solid lesions depends on whether the lesion is well-defined or infiltrative. The approach to well-defined lesions focuses mainly on the differentiation between renal cancer and benign tumors such as angiomyolipoma (AML) and oncocytoma. Differential diagnosis of infiltrative lesions is wider, including primary and secondary malignancies and inflammatory disease, and knowledge of the patient history is essential. Radiologists may establish a possible differential diagnosis based on the imaging features of the renal masses and the clinical history. The aim of this review is to present the contribution of the different imaging techniques and image guided biopsies in the diagnostic management of cystic and solid renal lesions.

Topics: Abscess; Adenoma; Adenoma, Oxyphilic; Angiomyolipoma; Carcinoma, Renal Cell; Carcinoma, Transitional Cell; Contrast Media; Cysts; Humans; Kidney Diseases; Kidney Neoplasms; Leiomyoma; Lymphoma; Magnetic Resonance Imaging; Plasmacytoma; Pyelonephritis; Pyelonephritis, Xanthogranulomatous; Tomography, X-Ray Computed; Ultrasonography; Ultrasonography, Doppler, Color

PubMed: 33435540
DOI: 10.3390/medicina57010051

Review

Do we need an updated classification of oncocytic renal tumors? : Emergence of low-grade oncocytic tumor (LOT) and eosinophilic vacuolated tumor (EVT) as novel renal entities.

Authors: Ondrej Hes, Kiril Trpkov

The category of "oncocytic renal tumors'' includes well-recognized entities, such as renal oncocytoma (RO) and eosinophilic variant of chromophobe renal cell carcinoma (eo-ChRCC), as well as a group of "gray zone" oncocytic tumors, with overlapping features between RO and eo-ChRCC that create ongoing diagnostic and classification problems. These types of renal tumors were designated in the past as "hybrid oncocytoma-chromophobe tumors". In a recent update, the Genitourinary Pathology Society (GUPS) proposed the term "oncocytic renal neoplasm of low malignant potential, not further classified", for such solitary and sporadic, somewhat heterogeneous, but relatively indolent tumors, with equivocal RO/eo-ChRCC features. GUPS also proposed that the term "hybrid oncocytic tumor" be reserved for tumors found in a hereditary setting, typically arising as bilateral and multifocal ones (as in Birt-Hogg-Dubé syndrome). More recent developments in the "gray zone" of oncocytic renal tumors revealed that potentially distinct entities may have been "hidden" in this group. Recent studies distinguished two new entities: "Eosinophilic Vacuolated Tumor" (EVT) and "Low-grade Oncocytic Tumor" (LOT). The rapidly accumulated evidence on EVT and LOT has validated the initial findings and has expanded the knowledge on these entities. Both are uniformly benign and are typically found in a sporadic setting, but rarely can be found in patients with tuberous sclerosis complex. Both have readily distinguishable morphologic and immunohistochemical features that separate them from similar renal tumors, without a need for detailed molecular studies. These tumors very frequently harbor TSC/MTOR mutations that are however neither specific nor restricted to these two entities. In this review, we outline a proposal for a working framework on how to classify such low-grade oncocytic renal tumors. We believe that such framework will facilitate their handling in practice and will stimulate further discussions and studies to fully elucidate their spectrum.

Topics: Adenoma, Oxyphilic; Biomarkers, Tumor; Carcinoma, Renal Cell; Humans; Kidney; Kidney Neoplasms

PubMed: 35273336
DOI: 10.1038/s41379-022-01057-z

Authors: Ginny Xiaohe Li, Lijun Chen, Yi Hsiao...

Non-clear cell renal cell carcinomas (non-ccRCCs) encompass diverse malignant and benign tumors. Refinement of differential diagnosis biomarkers, markers for early prognosis of aggressive disease, and therapeutic targets to complement immunotherapy are current clinical needs. Multi-omics analyses of 48 non-ccRCCs compared with 103 ccRCCs reveal proteogenomic, phosphorylation, glycosylation, and metabolic aberrations in RCC subtypes. RCCs with high genome instability display overexpression of IGF2BP3 and PYCR1. Integration of single-cell and bulk transcriptome data predicts diverse cell-of-origin and clarifies RCC subtype-specific proteogenomic signatures. Expression of biomarkers MAPRE3, ADGRF5, and GPNMB differentiates renal oncocytoma from chromophobe RCC, and PIGR and SOSTDC1 distinguish papillary RCC from MTSCC. This study expands our knowledge of proteogenomic signatures, biomarkers, and potential therapeutic targets in non-ccRCC.

Topics: Humans; Proteogenomics; Kidney Neoplasms; Biomarkers, Tumor; Carcinoma, Renal Cell; Transcriptome; Male; Female; Middle Aged; Gene Expression Regulation, Neoplastic

PubMed: 38703764
DOI: 10.1016/j.xcrm.2024.101547

Authors: Kiril Trpkov, Sean R Williamson, Yuan Gao...

AIM

To describe a group of distinct low-grade oncocytic renal tumours that demonstrate CD117 negative/cytokeratin (CK) 7-positive immunoprofile.

METHODS AND RESULTS

We identified 28 such tumours from four large renal tumour archives. We performed immunohistochemistry for: CK7, CD117, PAX8, CD10, AMACR, e-cadherin, CK20, CA9, AE1/AE3, vimentin, BerEP4, MOC31, CK5/6, p63, HMB45, melan A, CD15 and FH. In 14 cases we performed array CGH, with a successful result in nine cases. Median patient age was 66 years (range 49-78 years) with a male-to-female ratio of 1:1.8. Median tumour size was 3 cm (range 1.1-13.5 cm). All were single tumours, solid and tan-brown, without a syndromic association. On microscopy, all cases showed solid and compact nested growth. There were frequent areas of oedematous stroma with loosely arranged cells. The tumour cells had oncocytic cytoplasm with uniformly round to oval nuclei, but without significant irregularities, and showed only focal perinuclear halos. Negative CD117 and positive CK7 reactivity were present in all cases (in two cases there was focal and very weak CD117 reactivity). Uniform reactivity was found for PAX8, AE1/AE3, e-cadherin, BerEP4 and MOC31. Negative stains included CA9, CK20, vimentin, CK5/6, p63, HMB45, Melan A and CD15. CD10 and AMACR were either negative or focally positive; FH was retained. On array CGH, there were frequent deletions at 19p13.3 (seven of nine), 1p36.33 (five of nine) and 19q13.11 (four of nine); disomic status was found in two of nine cases. On follow-up (mean 31.8 months, range 1-118), all patients were alive with no disease progression.

CONCLUSION

Low-grade oncocytic tumours that are CD117-negative/CK7-positive demonstrate consistent and readily recognisable morphology, immunoprofile and indolent behaviour.

Topics: Adenoma, Oxyphilic; Aged; Biomarkers, Tumor; Female; Humans; Immunohistochemistry; Keratin-7; Kidney Neoplasms; Male; Middle Aged; Proto-Oncogene Proteins c-kit

PubMed: 30895640
DOI: 10.1111/his.13865

Authors: John W Davis

PubMed: 35783594
DOI: 10.1002/bco2.161

Authors: Yuantao Wang, Y U Hu, Xiuyu Zhai...

Renal oncocytoma is one of the most unusual benign lesion, which are usually diagnosed postoperatively, since their differentiation from renal cell carcinoma is challenging. The present study reports two cases of renal oncocytoma in a 60-year-old woman and a 46-year-old man. Relevant clinical and pathological data on the two patients were retrieved. The tumors were excised and the patients underwent laparoscopic radical nephrectomy. Typical features of oncocytoma were observed upon histological examination of the excised specimens. The postoperative course of each patient was uneventful and they were discharged 8 and 7 days post-surgery, respectively. In addition, the current study presents the results of a literature review regarding the radiological, immunohistochemical and pathological characteristics of renal oncocytoma.

PubMed: 27347140
DOI: 10.3892/ol.2016.4594

Authors: Ayo O Omiyale, James Carton

Renal oncocytoma is a benign epithelial neoplasm typically composed of large cells with granular eosinophilic cytoplasm. Although rare, histologically worrisome features such as vascular and perinephric fat invasion have been reported. Of the 159 renal oncocytomas resected at our institution, 20 (12.6%) had vascular and/or perinephric fat invasion. Microscopically, 10 oncocytomas had perinephric fat invasion, 7 had vascular invasion and 3 had both vascular and perinephric fat invasion. Grossly, perinephric fat invasion was visible in three cases and tumour was identified within the branches of the renal vein in two cases. Tumours occurred in 14 men and 6 women (M:F = 2.3:1). The mean age at diagnosis was 64.5 years (range, 33-88 years). A total of 11 cases had radical nephrectomies while 9 cases had partial nephrectomies. There was no evidence of disease recurrence, metastasis or death due to tumour after a mean follow up of 25.6 months (range, 2-103 months). The presence of vascular and perinephric fat invasion in renal oncocytoma though worrisome, does not alter the benign course of the tumour.

PubMed: 31700546
DOI: 10.1177/1756287219884857

Review

Authors: D S Katz, A M Gharagozloo, T R Peebles...

Renal oncocytoma is an uncommon benign renal neoplasm of unknown etiology. Bilateral, multicentric renal oncocytomas are rare and diffuse renal oncocytomas are even rarer. We report a patient with incidentally detected marked bilateral nephromegaly due to innumerable oncocytomas. The term "oncocytomatosis" should be strictly applied to cases in which oncocytomas diffusely infiltrate the kidneys.

Topics: Adenoma, Oxyphilic; Biopsy; Chronic Disease; Diagnosis, Differential; Dilatation, Pathologic; Humans; Kidney; Kidney Neoplasms; Male; Middle Aged; Tomography, X-Ray Computed

PubMed: 8678070
DOI: 10.1016/s0272-6386(96)90170-5