Living-donor transplantation after excision of unrecognized renal cancer diagnosed after transplant.

BACKGROUND: Published data on kidneys transplanted after resecting small renal cancers during the transplantation surgery are very rare and, to the best of our knowledge, no pediatric cases have been reported in the literature. CASE-DIAGNOSIS/TREATMENT: Our patient was diagnosed with a bilateral Wilms tumor when he was 15 months old. A total bilateral nephrectomy was required to control the disease. Two years later, a human leukocyte antigen (HLA)-identical living-donor transplant from his father was performed. A small mass in the father's left kidney was diagnosed as an angiomyolipoma during the pretransplant donor evaluation. During the surgery, the mass was excised and the kidney implanted. One week later, the pathological study revealed the mass to be a clear cell renal carcinoma. After joint discussion, the urologic and nephrologic teams and the family decided to maintain the transplant, managing the patient with monotherapy based on rapamycin and close ultrasound control. To date, 8 years after transplantation, no signs of malignancy have been detected, and renal function is normal. CONCLUSION: This is the first reported pediatric case of a living-donor graft with a small renal carcinoma excised in the operating room. No malignancy has been observed in 8 years of follow-up.

Acute renal failure due to bilateral pieloureteral stone impaction in a 10-month-old boy.

Urolithiasis (UL) can present with its classic signs and symptoms, such as flank or abdominal pain and gross hematuria. However, atypical complaints can be more common in younger children. We report here a case of bilateral ureteropelvic junction (UPJ) stones in a 10-month-old boy who only showed nonspecific symptoms at the time of presentation. The initial blood test revealed renal failure (serum creatinine 3.4 mg/dl), hyperkalemia (6.4 mEq/l), hyperphosphoremia (9.4 mEq/l) and mild metabolic acidosis. Medical treatment for electrolyte disorders was started. The ultrasonography revealed impacted stones in both ureteropelvic junctions. A pigtail catheter was placed in each ureter. High urine flow was promptly achieved after the pigtail procedure, and the serum creatinine level dropped quickly from 4.5 to 0.32 mg/dl. Quantitative determination of urinary amino acids by ion exchange chromatography showed high cystine levels of 8.43 mmol/g creatinine. Outpatient follow-up was scheduled every 3 months to monitor patient compliance with potassium citrate. In the first 6 months, the patient underwent three febrile urinary tract infections (UTIs). Since both pigtail catheters were removed, he has been free of UTIs and stones. Our case emphasizes the need for considering UL in infants who complain with unclear signs, because UL can only show nonspecific symptoms in children younger than 1 year old. Since cystinuria can cause loss of renal function due to urinary system obstruction and UTI, an early diagnosis and a close follow-up are the key to achieving the best long-term outcome.

[Children as receptors of living donors]. / El receptor infantil de donante vivo.

The most important factor in life expectancy for children on renal replacement therapy (RRT) is to have a functioning graft when they reach adulthood (63 years  on transplantation vs 37 years on dialysis). The pediatric recipient is very suitable for a living donor transplantation (LDT), with few contraindications. There are several reasons that make LDT the most recommended RRT in children: pre-emptive transplant avoiding dialysis, good renal mass, minimal cold ischemia time, better HLA-matching and the possibility to program the time of surgery. Long term graft survival in LDT is significantly better than in cadaveric donor transplantation (CDT) (81.3%  LDT vs 60.8 % CDT at 10 years follow-up). Calculated half-life graft survival for recipients aged 2-5 years reaches 27.5 years in some series, making LDT the ideal option for these children. Adolescent recipients (12-17 years) have an excellent early graft survival, but the worst long term outcome compared with the rest of pediatric population. However, preemptive LDT has a 70% of graft survival at 10 years. Late rejections episodes associated with non-adherence factors are found in all series. Unrelated LDT in pediatric recipients outcome remain unclear.

Antierythropoietin antibody-induced pure red cell aplasia: posttransplant evolution.

Pure red cell aplasia is a rare complication of recombinant human erythropoietin (rHuEPO) treatment, which physicians should consider once the more frequent causes of hyporegenerative anemia have been excluded. To our knowledge, no pediatric cases have been described. In our patient, cyclosporin A treatment enabled a reduction in the number of transfusions and the risk of hyperimmunization. After transplantation, our patient's hemoglobin level has remained normal and stable.