Wilms tumor arising in horseshoe kidney

Surgery for the complex Wilms tumour

The prognosis of children with Wilms tumour has greatly improved since the introduction of adjuvant radiotherapy and chemotherapy more than 70 years ago with a current overall long-term survival approaching 90%. Before this, surgery was the only option with around 20% survival, even in low-risk categories. The focus is now on management options for those patients in specific subgroups, who continue to have lower event-free survival and who suffer from the long-term effects of treatment. These include those with anaplastic histology, bilateral Wilms, biologically high-risk tumours and those that relapse (Aldrink et al. in J Pediatr Surg 54(3):390-397, 2019). The major advances that have already been made in risk assessment and tailoring the chemotherapy/radiotherapy to achieve maximum advantage with minimum toxicity and long-term morbidity have been predicated on safe and complete resection and staging of the tumour. There are, however, still surgical challenges faced with respect to resection of 'complex' tumours; thus, surgeons need to understand their role and advance their expertise in the overall treatment of children with Wilms tumour. These include very large tumours not responding to chemotherapy, ruptured tumours, tumours with intravascular invasion into the inferior vena cava (± 10%), heart and hepatic veins (± 4%) and Wilms tumours in horseshoe kidneys (< 1%) (Kieran and Ehrlich in Urol Oncol https://doi.org/10.1016/j.urolonc.2015.05.029, 2015). This review describes surgical strategies and techniques used in these situations, gleaned from the authors' experience in the surgical management of over 300 children with Wilms tumours in our centres over the last 30 years.

Wilms' tumor in a horseshoe kidney

The incidence of horseshoe kidney is about 1 in 400 cases. The presence of Wilms' tumor with a horseshoe kidney is unusual, and the occurrence of Wilms' tumor in a horseshoe kidney is estimated at 0.4 to 0.9% of all Wilms' tumors. We report the case of a 5-year-old boy who presented with a stage IV Wilms' tumor in a horseshoe kidney. The patient was treated with preoperative chemotherapy followed by surgical resection and adjuvant chemotherapy. This case illustrates the role of preoperative chemotherapy for preserving renal function and aims to highlight the multimodality treatment of Wilms' tumor.

Kidney fusion anomalies revisited: clinical and radiological analysis of 209 cases of crossed fused ectopia and horseshoe kidney

OBJECTIVE

To analyse the morphological appearance of horseshoe kidneys (HKs) and crossed fused ectopia (CFE) and to assess the frequency and clinical significance of associated anomalies and diseases.

PATIENTS AND METHODS

The findings and images of 209 patients with fused kidneys (FKs) were reviewed; in all, 244 scans from computed tomography (CT), 233 ultrasonograms and 89 micturition cysto-urethrograms, urograms, magnetic resonance images and angiograms were taken.

RESULTS

HKs (found in one of 474 abdominal CT scans) and CFEs (found in one of 3078 CT scans) showed a high variability of vasculature that could not be classified. However, some generalized conclusions were possible about the renal vasculature (430 arteries in 103 kidneys). Variants of the most cephalad artery of both sides were rare. The second artery on the right had a pre-caval course. The origins of vessels located further caudal were more ventral. CFEs were anatomically different from HKs with respect to lower position, greater axial rotation, smaller pelvic width, more caudal origin, and fewer vessels, but not in accompanying anomalies. Severe anomalies or malformations were found in 23% of patients, with half of them in the urogenital system. Malformations were found considerably more often in children than in adults. There was no increased incidence of diseases such as stones or inflammation of the renal pelvis.

CONCLUSION

Concomitant anomalies and diseases were equally frequent for HK and CFE, but less frequent than generally assumed. Individual cases of complex anatomical situations require special examination strategies, and CT appears to be the most reliable imaging method.

Wilms' tumor and horseshoe kidneys: a case report and review of the literature

The presence of Wilms' tumor with a horseshoe kidney is an unusual combined clinical presentation. It has been reported that the incidence of Wilms' tumor in patients with horseshoe kidneys is higher than that seen in the general population. The current report describes a 5-year-old boy who presented with a stage III Wilms' tumor in a horseshoe kidney. The patient was treated with neoadjuvant chemotherapy followed by surgical resection, adjuvant chemotherapy, and radiation. The patient is disease free 40 months after diagnosis. A review of all reported cases of Wilms' tumor with horseshoe kidneys in the English-language literature before July 2002 is presented.

The occurrence of Wilms tumor in horseshoe kidneys: a report from the National Wilms Tumor Study Group (NWTSG)

BACKGROUND/PURPOSE

An increased incidence of Wilms tumor has been noted in patients with a horseshoe kidney. These represent a difficult diagnostic and therapeutic challenge. The charts of all National Wilms Tumor Study Group (NWTSG) patients with Wilms tumor occurring in a horseshoe kidney were reviewed.

METHODS

From 1969 to 1998, 8,617 patients were enrolled in the NWTSG. Forty-one patients were found to have a Wilms tumor arising in a horseshoe kidney for an incidence of 0.48%. Their records were reviewed retrospectively.

RESULTS

Horseshoe kidney was not recognized preoperatively in 13 patients, 10 of whom were evaluated with computed tomography (CT). Four of the 10 also had renal ultrasonography and one an intravenous pyelogram (IVP). Two of the 13 were evaluated with an IVP only, and the last had no preoperative imaging studies performed. Stage at presentation was stage I, 10 pts; stage II, 10; stage III, 12; stage IV, 6; stage V, 3. Primary surgical resection was performed in 26 patients, including 23 nephrectomies and 3 partial nephrectomies. Fifteen children were treated with preoperative chemotherapy after initial biopsy of the tumor. The mean total remaining renal parenchyma after all operations (excluding treatment of relapses) was approximately 75%. Surgical complications occurred in 14.6% of patients, including 2 urine leaks, 2 ureteral obstructions, and 1 ureteral injury. Two patients had transient renal failure.

CONCLUSIONS

The diagnosis of horseshoe kidney often was missed on preoperative imaging. Accurate preoperative diagnosis is important in planning the operative approach and may help to decrease complications related to transection of the urinary collecting system. Although 37% of patients with Wilms tumor arising in a horseshoe kidney were judged inoperable at initial exploration, all were amenable to resection after chemotherapy.

[Kidney cancer in horseshoe kidney. A case report of an unexpected diagnosis]

The authors report a case of renal cell carcinoma in a horseshoe kidney and discuss diagnostic and therapeutical aspects arising from this combination. Renal carcinoid tumors and nephroblastoma seems to be more frequent in this malformation. Diagnosis of horseshoe kidney may be difficult and angiography examination is very useful to confirm renal anomaly, tumor situation, and to plan the surgical approach because vascularization vary case to case. Heminephrectomy adapted to neoplasic localisation remains the essential treatment.

Non-11p constitutional chromosome abnormalities in Wilms' tumor patients

The incidence in Wilms' tumor patients of constitutional chromosome defects other than those involving the short arm of chromosome 11 was examined using data on 5,854 patients registered in the National Wilms Tumor Study. Trisomy 18 and Turner syndromes were found to occur at higher rates than expected based on chromosome surveys of newborns. Four patients were reported to have trisomy 18; all of these patients were over 5 years of age at the time of diagnosis of Wilms' tumor and none survived longer than six months. Four patients were reported to have Turner syndrome; these patients are currently doing well and have all survived at least 3 years following diagnosis. Two of the Turner patients and one of the trisomy 18 patients had horse-shoe kidneys; we speculate that this renal anomaly may contribute to the higher rates of tumor in these patients. No clear pattern was found among patients with other chromosome defects, although two patients had defects involving 2q37.

Wilms' tumor in horseshoe kidney: presentation due to ureteropelvic junction obstruction

Children with horseshoe kidney usually develop urinary tract symptoms and often require operative correction of the anomaly. The incidence of Wilms' tumor in horseshoe kidney is higher than that for the general population. We present the case of a child whose Wilms' tumor was diagnosed early because of ureteropelvic junction obstruction secondary to a horseshoe kidney. A high index of suspicion should be maintained for Wilms' tumor in any child with a horseshoe kidney.

Renal cell carcinoma in horseshoe kidney associated with Turner syndrome and caval extension

The first case of renal cell carcinoma in a horseshoe kidney associated with Turner syndrome is reported. Therapeutic and diagnostic aspects are discussed; the literature is reviewed.