Case Report

Figure 1. CT demonstrated a large abscess formation of the right kidney and calculi in the pelvis.

A 55-year-old man presented with recurrent episodes of septicemia due to nephrolithiasis and right-sided hydronephrosis. A perirenal abscess of the right kidney with nephrolithiasis was described on CT scanning (Figure 1). In the past, there had been several interventions for recurrent stone disease. Also, the patient had been suffering from a neurogenic bladder disorder due to meningomyelocele and spina bifida. For 20 years, this had been managed by indwelling urinary catheter only. Five years ago, he underwent simple cystectomy with an ileal conduit. Other comorbidities were diabetes mellitus and arterial hypertension. The CT scan showed a nonfunctioning right kidney, the abscess was surgically drained, and a nephrectomy was performed. Surprisingly, pathology showed a locally advanced and squamous cell carcinoma of the renal pelvis (pT4 pN2 (2/4) V1 L1 Pn1 R2 G3; Figure 2). A 1.5 cm stone was also found in the renal pelvis.

Figure 2. Squamous cell carcinoma of the renal pelvis. A, Hematoxylin and eosin–stained sections revealed a moderately to weakly differentiated solid carcinoma with squamous morphology and focal keratinization against an inflammatory background. Original magnification ×100. B, Squamous cell differentiation was further highlighted by positive CK5/6 immunohistochemistry. Original magnification ×100.

The postoperative course was unremarkable. Due to the incomplete resection in the perinephric adipose tissue, systemic chemotherapy with cisplatin/paclitaxel/ifosphamide was advised but refused by the patient. Instead, immunotherapy with pembrolizumab was initiated. The patient received a total of 3 cycles with progressive deterioration of his general condition. Three months after the surgery, the patient was hospitalized again in septic shock and disease progression with cutaneous metastases. Palliative care was implemented, and the patient died a few days later.

Discussion

Upper urinary tract tumors constitute 5% of all urothelial cancers. Squamous cell carcinomas (SCC) are even more rare in this localization, amounting to just 0.5% of all upper urinary tract tumors. SCCs of the urothelium usually occur in late adulthood (aged 50–70 years) and are usually diagnosed after surgery and at advanced stages. There are no typical clinical and radiological properties. Due to their rarity and the often-advanced stage at the time of diagnosis, SCC of the renal pelvis and ureter are a therapeutic challenge. Since the first description of this entity in 1878 (Hedenius and Waldenstroem), fewer than 400 cases have been published worldwide. Accordingly, there are neither evidence-based guidelines nor extensive experience in any one center. Treatment recommendations are based on the case series published to date.^1,2 In 48% of cases, the cause is of SCC development from urothelium is considered to be nephrolithiasis with chronic irritation and inflammation of the urothelium of the renal pelvis.^2-4 CT and ultrasound are important tools to evaluate renal malignancies. However, the diagnosis of renal pelvic SCC is difficult because both CT and ultrasound in such cases usually show only calculi and hydronephrosis due to obstruction.^5,6 Adjuvant (cisplatin-based) chemotherapy and radiotherapy have no lasting benefits for overall survival of renal SCC.⁷ Five-year overall survival is approximately 10% and most of these patients die within 1 year of diagnosis.^8,9 When diagnosed in early stages, a potentially curative option is radical nephroureterectomy, but the prognosis remains difficult.

Clinical Practice Points

SCC of the upper urinary tract are rare and have a poor prognosis due to the usually late diagnosis and the lack of evidence-based treatment strategies. Treatment is primarily surgical. In advanced stages, systemic therapy may be used analogous to the treatment schemes for squamous cell carcinoma of nonurological origin.