Primary Squamous Cell Carcinoma of Kidney Associated With Large Calculus in Non-functioning Kidney: A Case Report

Application of warning biopsies in percutaneous nephrolithotomy

Background

At present, few articles on percutaneous nephrolithotomy (PCNL) for renal calculi and renal pelvic tumors detected by intraoperative biopsy exist, which has provided limited guidance for clinical practice. In this article, we aimed to further study the relationship between renal calculi and renal pelvic tumors.

Methods

We retrospectively analyzed the medical records of patients with abnormal mucosal biopsy results who underwent PCNL for kidney stones in the Urology Department of Peking University People's Hospital from January 2011 to November 2021.

Results

In total, 2,801 patients underwent PCNL for kidney stones, of whom 69 underwent intraoperative mucosal biopsy. Biopsy results indicated that 8 cases were malignant (11.60%), and 61 cases were benign (88.40%). All malignant cases were renal pelvic carcinoma. Seven were urothelial carcinoma, and one of these was urothelial carcinoma with squamous differentiation. Only one was squamous cell carcinoma. The preoperative information of patients with a malignant mucosa biopsy was analyzed. To provide clinical guidance, an early warning biopsy system was established based on the abnormal mucosa found during the operation. We found that PCNL should be considered if the following risk factors are associated with stones: advanced age, long history of kidney stones, severe hydronephrosis, urinary tract infection, multiple or staghorn stones.

Conclusions

Early warning information should be established for patients with kidney stones based on preoperative clinical characteristics and intraoperative mucous membrane observations. An early warning biopsy should be performed for patients with possible tumors to detect tumors in a timely manner and provide early treatment to improve patient prognosis.

Incidental Diagnosis of Renal Pelvic Tumor in Patients Who Underwent Percutaneous Nephrolithotomy: A Report of 6 Cases and Review of the Literature

OBJECTIVES

To report the clinical characteristics of patients who were incidentally diagnosed as renal pelvic tumor during or after percutaneous nephrolithotomy (PNL).

METHODS

The profiles of about 8,000 patients who underwent PNL in our center from 2011 to 2021 were retrospectively reviewed, 6 patients were diagnosed with renal pelvic tumor during or after PNL. Clinical data of these six patients were collected and summarized.

RESULTS

Four males and two females with the average age of 59 years were researched. Chief complaints included loin pain, gross hematuria, and wound infection after PNL. Two patients had a definite long history of stones. Urinary tract infection occurred in 5 patients and all six patients had gross hematuria or microscopic hematuria. CT images revealed severe hydronephrosis in 4 patients and moderate hydronephrosis in 2 patients. Both staghorn and multiple stones were separately seen in 3 patients. Five patients were diagnosed with renal pelvic urothelial carcinoma via biopsy during PNL. One patient was diagnosed as renal pelvic tumor with extensive invasion by postoperative CT scan and received palliative treatment. Of two patients underwent radical surgery, one patient obtained long survival, one patient received endoscopic tumor resection and also obtained long survival. Two patients underwent renal artery embolization, one patient was still alive after 22 months, the other patient showed tumor growth in 3 weeks.

CONCLUSIONS

The possibility of renal pelvic tumor should be considered in stone patients with several risk factors including elder age, long history of stones, complicated stones, hydronephrosis especially pyonephrosis, obvious hematuria etc.

A case report of complete pathological remission after chemotherapy in a patient with primary renal squamous cell carcinoma

This is the first case report of the outcomes of systemic chemotherapy in a patient with locally advanced renal squamous cell carcinoma, a rare tumor, as well as the first next generation sequencing study of this rare tumor. The patient's main symptoms were fever and low back pain. Initial positron emission tomography and computed tomography (PET-CT) suggested a malignant renal tumor at onset, but biopsy confirmed renal squamous cell carcinoma. Next generation sequencing showed a low level of microsatellite instability (MSI-L), a high tumor mutational burden (TMB-H), a high neoantigen burden (TNB-H), and a strong loss of heterozygosity (LOH) for human leukocyte antigen (HLA), with 67 deleterious mutations. The patient achieved partial radiological remission after a cycle of systemic chemotherapy with albumin-bound paclitaxel combined with nedaplatin. After radical resection of the left renal tumor, postoperative pathology confirmed complete tumor remission and tumor-like xanthogranulomatous pyelonephritis. Conclusion: This renal squamous cell carcinoma patient responded to systemic chemotherapy with paclitaxel combined with platinum, providing a reference for the future treatment of similar cases. Pathology and gene sequencing indicated that renal squamous cell carcinoma occurred in a background of active inflammation and that the tumor evolved immune escape mechanisms such as loss of HLA heterozygosity, with gene repair defects and TMB-H.