High-grade eosinophilic renal tumor/eosinophilic vacuolar renal tumor: a case report and literature review.

Introduction: Renal oncocytoma (RO) is an uncommon benign neoplasm of the kidney, while eosinophilic vacuolated tumor (EVT) represents a distinct subtype of renal oncocytoma characterized by specific morphological features. EVT is a rare eosinophilic renal neoplasm distinguished by its unique morphological, immunophenotypic, and molecular genetic attributes. Its biological behavior is generally indolent, and it is associated with a favorable prognosis.

Case report: This case report provides a comprehensive account of a 52-year-old female patient who presented to the hospital for a medical evaluation, revealing that her left kidney had been occupying space for over one month. Following an abdominal enhanced CT scan, a diagnosis of renal clear cell carcinoma was suspected, leading to the decision to perform a "robot-assisted laparoscopic partial left nephrectomy." During the surgical procedure, a mass measuring approximately 3.8 × 3.5 cm was identified adjacent to the renal hilum in the midsection of the left kidney. Subsequent pathological analysis classified the excised tumor as an eosinophilic vacuolar tumor of the kidney.

Conclusion: This case illustrates that EVT represents a novel solid neoplasm of the kidney, with occurrences being exceedingly uncommon. It is imperative for clinicians and pathologists to enhance their comprehension of these tumors and distinguish them effectively, thereby facilitating more precise classification of renal tumors and informing clinical management and prognostic assessment.