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A 25-year-old woman presented 6 months post-partum, complaining of multiple abdominal swellings progressively increasing in size and number, abdominal distension, anorexia, and a dull ache in the left flank for 5 months. There was no history of fever, cough, haematuria or other urinary complaints. The patient had delivered a premature male baby at seven and a half months gestation. The pregnancy and labour were uneventful and the patient was lactating at presentation. Examination revealed a markedly cachectic young woman with gross abdominal distension. Her pulse was 94 beats/min, regular, and blood pressure was 100/60 mmHg. Abdominal examination revealed a 10.0 × 12.5 cm large, irregular, firm, bimanually palpable mass in the left hypochondrium extending into the left lumbar and umbilical regions. Multiple hard, irregular masses, some confluent, others discrete, were palpated over all areas of the abdomen. A 6-cm firm, irregular hepatomegaly was present. The rest of the physical examination, including a per-vagina examination, was unremarkable. Contrast-enhanced computed tomography (CT) of the abdomen is shown in figure 1. The patient refused major surgery and a biopsy from the mass was taken. The histology is shown in figures 2 and3.
- Comment on the CT findings.
- Describe the histological features.
- What is the staging system for the tumour; what stage is this patient's tumour?
The CT scan of the abdomen (figure 1) shows a large, hetero-echoic left renal mass 11.8 × 12.5 cm, with multiple hepatic and peritoneal secondaries.
The biopsy from the left renal mass shows the tissue to be made up of blastemal cells in sheets. The cells are forming a large number of abortive tubular and occasional glomeruloid structures. Areas of necrosis are also seen (figure 2). The individual cells are oval to spindle shaped with scant cytoplasm and hyperchromatic nuclei, and show moderate nuclear variation and mitotic activity. The histological picture is suggestive of a nephroblastoma or Wilms tumour (WT).
Nephroblastoma or WT is the most common renal tumour in children accounting for 5–10% of all pediatric neoplasia.2 WT is infrequent in adults, less than 200 cases having been reported worldwide.3 The exact incidence of adult WT is difficult to determine because of confusing nosology and different criteria used for diagnosis. The most widely accepted diagnostic criteria were devised by Kilton and associates,4 and are summarised in box FB2.
WT is believed to originate from the totipotential cells of the metanephrogenic blastema.5 Flank pain, the presence of an abdominal mass and/or haematuria, associated with constitutional symptoms are the usual clinical manifestations.
Adults with WT have a poorer outcome than children. Survival rates of 18% to 27% in adults, have been described, compared to 95% cure rates in children.6 Adults with WT have a more widespread disease at presentation: 50% with stage III/IV,7 in contrast to 20% with stage III and 11% stage IV disease in children.8 This is chiefly responsible for the poorer outlook of adult WT. Age, earlier suggested as a poor prognostic marker, is no longer regarded as a determinant of prognosis.8 Tumour histology determines prognosis, with unfavourable histology indicating a poor outcome. Whether adults with WT have a greater frequency of unfavourable histology compared to children is debatable.
The earliest protocols for the treatment of children with WT were laid down by NWTS 19 and 2.8 The treatment of patients was not stratified according to histology in NWTS 1 and 2, and the subsequent NWTS 310 and 411 have incorporated histology in the selection for the treatment protocols. The NWTS are based on the strategy of immediate nephrectomy followed by radiotherapy and/or chemotherapy, depending upon the stage and histology of the tumour. The treatment recommendations of NWTS 3 are summarised in the table. NWTS 4 is evaluating the possible benefit of early intensification of treatment in WT and compares a pulse-intensive treatment regimen with standard treatment protocols in an attempt to evolve an effective alternative treatment regimen with fewer adverse effects and lower costs. Treatment protocols for anaplastic tumours are not well devised. The prognosis for patients with diffuse anaplastic WT is better when cyclophosphamide is added to the standard three-drug regimen.13 However a similar response is not observed in WT with focal anaplasia. For patients who relapse after an initial response, salvage therapy using drugs such as VP16, cisplatin, and ifofsamide is advised.2
Pregnancy outcome is adversely affected with more low birth weight babies and perinatal deaths in adult survivors who received abdominal irradiation for a childhood WT.14 However, there are no published data on the effect of WT on pregnancy outcomes in adult female patients harbouring a WT and vice versa.
This patient refused any major surgery and/or radio- or chemo-therapy and succumbed 4 weeks later.
Adult Wilms tumour stage IV.