Renal Oncocytic Neoplasms: Review of Classification Updates, Imaging, and Management

Area of Science:

• Nephrology
• Oncology
• Radiology

Background:

• Renal oncocytic neoplasms pose diagnostic challenges in imaging and pathology.
• The World Health Organization classification includes emerging entities, aiding characterization.
• Low-grade oncocytic tumors and eosinophilic vacuolated tumors exhibit indolent behavior.

Purpose of the Study:

• To review the diagnostic challenges and management strategies for renal oncocytic neoplasms.
• To discuss the role of imaging and pathology in differentiating benign from malignant oncocytic tumors.
• To explore the potential of active surveillance and emerging imaging techniques.

Main Methods:

• Review of current literature on renal oncocytic neoplasms.
• Analysis of imaging features and pathological classifications.
• Discussion of diagnostic difficulties and management options.

Main Results:

• Imaging appearances of oncocytic neoplasms are often similar, leading to high resection rates of benign tumors like oncocytomas.
• Renal mass biopsy has limitations in accuracy and reliability for determining aggressiveness.
• Malignant oncocytic tumors, like chromophobe renal cell carcinoma, are less aggressive than clear cell subtypes but challenging to distinguish.
• Imaging features such as enhancement, heterogeneity, and calcification may help differentiate benign from malignant and low-grade from high-grade tumors.

Conclusions:

• Accurate preoperative diagnosis of renal oncocytic neoplasms remains difficult, contributing to overtreatment.
• Active surveillance is a viable option for some patients, but criteria need refinement.
• Emerging imaging techniques, including molecular imaging and MR fingerprinting, show promise for improved risk stratification.