Bilateral benign renal oncocytomas and the role of renal biopsy: single institution review

Artificial Intelligence in Renal Cell Carcinoma Histopathology: Current Applications and Future Perspectives

Renal cell carcinoma (RCC) is characterized by its diverse histopathological features, which pose possible challenges to accurate diagnosis and prognosis. A comprehensive literature review was conducted to explore recent advancements in the field of artificial intelligence (AI) in RCC pathology. The aim of this paper is to assess whether these advancements hold promise in improving the precision, efficiency, and objectivity of histopathological analysis for RCC, while also reducing costs and interobserver variability and potentially alleviating the labor and time burden experienced by pathologists. The reviewed AI-powered approaches demonstrate effective identification and classification abilities regarding several histopathological features associated with RCC, facilitating accurate diagnosis, grading, and prognosis prediction and enabling precise and reliable assessments. Nevertheless, implementing AI in renal cell carcinoma generates challenges concerning standardization, generalizability, benchmarking performance, and integration of data into clinical workflows. Developing methodologies that enable pathologists to interpret AI decisions accurately is imperative. Moreover, establishing more robust and standardized validation workflows is crucial to instill confidence in AI-powered systems' outcomes. These efforts are vital for advancing current state-of-the-art practices and enhancing patient care in the future.

Triple Threat: Three Primary Malignancies Simultaneously Involving Three Genitourinary Organs

Statistically, the chance of having concurrent renal cell carcinoma (RCC), urothelial carcinoma of the bladder (UC), and a neuroendocrine tumor (NET) of the renal parenchyma is less than one in a trillion. Herein, we describe an unusual case of a 67-year-old female who presented with bilateral flank pain and severe gross hematuria. Cross-sectional imaging revealed two large heterogeneous, endophytic renal masses with a single enlarged paracaval lymph node. Diagnostic cystoscopy was performed for completion of gross hematuria evaluation and revealed a concurrent papillary bladder tumor. Percutaneous biopsies of bilateral renal masses revealed clear cell RCC involving the left kidney and well-differentiated NET involving the right kidney, and transurethral resection of the bladder tumor revealed high-grade nonmuscle invasive urothelial carcinoma. The patient elected to undergo bilateral nephroureterectomy, radical cystectomy, and retroperitoneal and pelvic lymphadenectomy. Final pathology confirmed the presence of three different malignancies: noninvasive high-grade papillary UC of the bladder (pTaN0), left renal clear cell RCC (pT2bN0), right renal well-differentiated NET, and a single paracaval lymph nodes positive for metastatic NET (pT2aN1).

Bilateral Renal Oncocytoma: Active Surveillance Versus Partial Nephrectomy

Renal oncocytomas (ROs) are benign tumors comprising 16% of renal masses. Due to the overlapping phenotypes seen in RO and chromophobe renal cell carcinoma (RCC) and lack of specific clinical and laboratory characteristics of RO, physicians face a challenge when arriving at a definitive diagnosis of RO. ROs additionally appear indistinct from RCCs on CT scan, contributing further to the difficulty of arriving at a clear diagnosis of RO. 

This is a case report of a 66-year-old man who presented with flank pain found to be related to bilateral ROs and underwent bilateral partial nephrectomies.

ROs are benign small renal masses that often pose a diagnostic challenge since preoperative diagnosis can be difficult to achieve. Given advancements in technology, active surveillance with core renal biopsy is a promising approach to accurately diagnose and manage ROs conservatively. The application of these techniques has wide-reaching implications for patients and physicians by reducing the need for a potentially harmful surgery and creating a cost-effective way to manage a diagnosis.

Renal oncocytoma with vascular and perinephric fat invasion

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.

Approach for Renal Tumors With Low Nephrometry Score Through Unclamped Sutureless Laparoscopic Enucleation Technique: Functional and Oncologic Outcomes

PURPOSE

We report an unclamped sutureless laparoscopic simple enucleation (LSE) technique for renal tumors with low nephrometry score and analyze complication rates as well as functional and oncologic outcomes.

PATIENTS AND METHODS

We reviewed the data of 143 consecutive patients who underwent sutureless laparoscopic tumor enucleation with zero ischemia by a single experienced laparoscopic surgeon. The inclusion criteria for LSE with zero ischemia were tumor size ≤ 5 cm and RENAL nephrometry score of 4 to 6. The following data were collected: age, gender, body mass index, tumor side, renal function, tumor characteristics, American Society of Anesthesiologists score, operative time, positive surgical margins, estimated blood loss, and surgical complications.

RESULTS

The median RENAL score of patients was 4.7. Median tumor size was 2.7 cm. Conversion to open surgery and hilum vessels clamped were not necessary in any patient. There were no changes in postoperative creatinine values and estimated glomerular filtration rate. The median operation duration time was 78.2 minutes, and median estimated blood loss was 110.2 mL. The median hospital stay was 3.8 days. A total of 2.8% of the patients had positive surgical margins at pathologic examination. Of the 143 patients, 7% developed fever after surgery requiring an adequate antibiotic regimen, 1.4% developed postoperative bleeding requiring blood transfusions, and 0.7% had postoperative urinary leakage from the drainage requiring double-J stent position.

CONCLUSION

The unclamped sutureless LSE is a rational and safe approach to renal tumors with a low nephrometry score. This surgical technique does not increase the complication rate despite the reduction in parenchymal mass excised and the absence of hilar control.