Cases description
We report our experience of nephron sparing surgery (NSS) in three
patients (two boys and a girl) aged 6, 9 and 16 months at diagnosis of
BWT and unilateral BGP managed between 1990 and 2020 in our center.
Patient’s characteristics are presented in Supplemental Table. The
clinical presentation was a gross hematuria (patient 1) and an abdominal
mass (patients 2 and 3). A severe hypertension was found in patients 1
and 3. Two children (patient 2 and 3) presented a WT1 predisposition
syndrome.
CT scan showed an obstruction of the collecting system with the three
calyx dilated in two cases but the BGP was diagnosed on preoperative
imaging in only one case (patient 1), with a mass growing into the renal
pelvis, while it was discovered during surgery in the other cases
(figure 1). The median WT diameter was 11.7 cm.
All three patients had neo-adjuvant chemotherapy according to the SIOP
protocols, with Actinomycin D and Vincristine for 3, 4 and 8 weeks, with
a very poor response. The date of surgery was brought forward for
patients 1 and 2. Doxorubicin, Etoposide and Carboplatin were added in
patient 3 but still with little response.
A two-step surgery was performed in all cases, 9 days, 10 days and 1
month apart. The BGP was located on the right kidney for each patient
and was easily removed in the three cases, with no adherences to the
pelvic wall. The calyx and renal pelvis were opened in all cases in
order to remove the tumor and then closed leaving a ureteral catheter
and a draining system near the calyx sutures. The BGP was removed along
with the whole tumor, with no rupture and no postoperative leak. On the
other side, NSS was realized in two patients, and a total nephrectomy
was performed in patient 3. The remaining renal parenchyma assessed
according to our recent publication3 represented
73/200%, 83/200% and 50/200% respectively in patients 1, 2 and 3.
(Figure 2)
The histology of the tumor with BGP was intermediate risk (stromal and
mixed type), stage I (patients 2 and 3) and stage II for sinus invasion
(patient 1). It was identical in both kidneys for the three patients.
The histology of the BGP itself was Intra Lobar Nephrogenic Rest (ILNR)
in all cases. Patients received adjuvant chemotherapy according to SIOP
protocols for 4 to 8 weeks with no radiation. Patient 1 had an early
hepatic relapse (3 months after the end of adjuvant treatment) treated
with chemotherapy and tumorectomy of the metastasis.
At a follow-up of 9 months (patient 3), 22 (patient 2) and 23 (patient
1) years, all patients are alive, with a treated hypertension. The
Modification of Diet in Renal Disease (MDRD) formula showed a moderate
renal insufficiency in the two oldest patients (61ml/mn and 76ml/mn).
For the third patient, who is still a toddler, the estimated glomerular
filtration rate was slightly decreased (eGFR=
72.9ml/min/1.73m2).