|Year : 2022 | Volume
| Issue : 6 | Page : 775-777
Renal primitive neuroectodermal tumor mimicking Wilms' tumor in a young boy: A case report of a rare entity with review of the literature
Miloni More1, Dhaarani Jayaraman2, Ramesh Babu3, Banukeerthana Rajasekaran4, Jensy Jaison5, Julius Xavier Scott2
1 Department of Pediatrics, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
2 Department of Pediatrics, Division of Pediatric Hemato-Oncology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
3 Department of Pediatric Urology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
4 Department of Pathology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
5 Department of Radio Diagnosis, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
|Date of Submission||11-Apr-2022|
|Date of Decision||08-Jul-2022|
|Date of Acceptance||12-Sep-2022|
|Date of Web Publication||14-Nov-2022|
Department of Pediatrics, Division of Pediatric Hemato-Oncology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Primary renal primitive neuroectodermal tumors (PNET) are an extremely rare entity. The tumor is very aggressive presenting with metastasis and carries a dismal prognosis. We describe the case of renal PNET in an 11-year-old boy with a solid cystic lesion in the right kidney with a thrombus in the inferior vena cava and lung nodules, mimicking Wilms' tumor.
Keywords: Ewing's sarcoma, hematuria, kidney, primitive neuroectodermal tumor, renal mass
|How to cite this article:|
More M, Jayaraman D, Babu R, Rajasekaran B, Jaison J, Scott JX. Renal primitive neuroectodermal tumor mimicking Wilms' tumor in a young boy: A case report of a rare entity with review of the literature. J Indian Assoc Pediatr Surg 2022;27:775-7
|How to cite this URL:|
More M, Jayaraman D, Babu R, Rajasekaran B, Jaison J, Scott JX. Renal primitive neuroectodermal tumor mimicking Wilms' tumor in a young boy: A case report of a rare entity with review of the literature. J Indian Assoc Pediatr Surg [serial online] 2022 [cited 2022 Nov 30];27:775-7. Available from: https://www.jiaps.com/text.asp?2022/27/6/775/360962
| Introduction|| |
Primitive neuroectodermal tumors (PNET) originate from neural crest cells and neuroectoderm; they either originate in the central nervous system or in other peripheral tissues. Here, we report the case of an 11-year-old boy who presented with hematuria with renal mass and was finally diagnosed with renal PNET.
| Case Report|| |
An 11-year-old boy from North India presented to us with hematuria for 7 days. He did not have any significant past medical or family history. His birth and developmental history were normal. On physical examination, a hard mass was palpable in the right lumbar region, approximately 10 cm × 7 cm with normal blood pressure. There were no dysmorphisms or external anomalies. His complete blood count and renal and liver function tests were within normal limits. Serum alpha-fetoprotein and beta-human chorionic gonadotropin were normal; uric acid and lactate dehydrogenase were normal. The urine routine showed plenty of red blood cells.
Contrast-enhanced computer tomography abdomen showed a large well-defined solid cystic lesion of size 12.2 cm × 11.6 cm × 20.2 cm in the right renal fossa noted with few areas of calcification and multiple arteriovenous shunts within the lesion. Thrombus of the right renal vein and near-complete thrombus in the infrahepatic inferior vena cava (IVC) was also noted. The left kidney was normal. The visualized section of the thorax revealed multiple soft-tissue nodules of varying sizes scattered in bilateral lung fields with acute partial pulmonary thromboembolism of bilateral descending pulmonary arteries [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d. The possibility of metastatic Wilms' tumor was considered in view of the characteristic location of mass with vein invasion and lung metastasis. In view of his age, he underwent an ultrasound-guided biopsy of the lesion, which revealed sheets of small round blue cells with scant cytoplasm and hyperchromatic nucleus and adjacent areas of necrosis. The tumor was positive for NKX2.2 and negative for WT1, synaptophysin, chromogranin, CD10, and CD45. The tumor was found to be positive for CD99 and immunohistochemistry (IHC) features being suggestive of PNET [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d. The family was counseled about the need for intensive multimodality treatment and the anticipated poor prognosis due to social reasons; the family opted to initiate treatment in their native place and was lost to follow-up.
|Figure 1: Pathology images showing, (a) tumor cells with diffuse sheets (H and E, 100), (b) pseudorosette formation (H and E, 100), (c) immunohistochemistry neoplastic cells positive for NKx2.2 (H and E, 100), and (d) immunohistochemistry neoplastic cells positive for CD99 (H and E, 100)|
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|Figure 2: Radiological images showing. (a) Coronal section right kidney not separately visualized with (phantom organ sign), (b) Thrombus of right renal vein and IVC, (c). Multiple Arteriovenous shuntings were noted within the lesion, (d) homogenously enhancing soft-tissue nodules–lung metastasis, IVC: Inferior vena cava|
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| Discussion|| |
The first reported case of renal PNET was in 1994, by Mor et al. The incidence of renal PNET is rare across the globe, with only a handful being reported. Popov et al. studied renal tumors in 1492 children aged 10–16 years and found only 67 (4.6%) of children to have nonrenal pathologies. Amongst these, the incidence of renal PNET was merely 3% (2 children). The median age of presentation was 24.9 years and 37.5% of patients presented with metastases. Tumor thrombi in adjacent renal vessels occurred in 56.2%.
Ünal et al. surveyed 20 children with nonWilm's tumors in Turkey and reported the case of a 2.5-month-old girl infant with bilateral renal PNET.
Major differentials to be considered for small round cell tumors from kidney, all with similar morphological features, include malignant lymphoma, rhabdomyosarcoma, renal neuroblastoma, Wilms' tumor, small-cell osteosarcoma, desmoplastic small-cell tumor, synovial sarcoma, small-cell neuroendocrine carcinoma, and PNET.
Sarcomas of the kidney usually remain asymptomatic until they are large enough to produce symptoms. Clinical symptoms include abdominal or flank pain, hematuria, and palpable mass. Systemic symptoms such as fever and weight loss have been observed.
Imaging characteristics of renal PNET overlap with other renal tumors such as Wilm's tumor, renal cell carcinoma, neuroblastoma, and lymphoma. Most commonly an ill-defined, large heterogeneous renal mass includes areas of internal hemorrhage or necrosis, peripheral hypervascularity, and diffuse calcification; venous extension into the renal vein, IVC, and right heart have also been described.
The ultimate diagnosis of renal PNET tumors is difficult and is solely based on histopathology and IHC findings. They are characterized by small uniform round cells with dark nuclei, ill-defined cytoplasmic borders, and poorly formed rosette structures. IHC plays an important role in differentiating from other differentials, as mentioned earlier. PNET shows a strong positivity for CD99, MIC-2 gene product, and FLI-1 with variable positivity for neuron specific enolase (NSE) and synaptophysin. WT1, a marker for Wilm's tumor, is not seen in PNET.
Renal PNET is a very aggressive tumor which is often diagnosed at an advanced stage, after the involvement of perinephric fat, hilar lymph nodes, renal veins, and the IVC. About 50% of cases come with distant metastasis at initial presentation, which include lungs, liver, spleen, and peritoneum. The treatment for renal PNET includes a combination of surgery, chemotherapy, and radiation. Surgical options include partial or total/radical nephrectomy with cavotomy in cases of renal vein involvement. Nephron-sparing surgery performed in early renal PNET has also been reported and showed a favorable outcome. The 5-year disease-free survival rate in cases of renal PNET appears worse at 20% despite aggressive multimodality therapy including chemotherapy, radiotherapy, surgery, and high-dose chemotherapy with autologous stem cell rescue.,
We report this case to pediatric oncologists, radiologists, and pathologists to be aware of this unusual site for PNET and consider this in the differential diagnosis, especially in older children where the incidence of non-Wilm's histology is relatively more.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given her consent for images and other clinical information to be reported in the journal. The guardian understands that her names and initials will not be published and due efforts will be made to conceal the patient's identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Mor Y, Nass D, Raviv G, Neumann Y, Nativ O, Goldwasser B. Malignant peripheral primitive neuroectodermal tumor (PNET) of the kidney. Med Pediatr Oncol 1994;23:437-40.
Popov SD, Sebire NJ, Pritchard-Jones K, Vujanić GM. Renal tumors in children aged 10-16 years: A report from the United Kingdom children's cancer and Leukaemia Group. Pediatr Dev Pathol 2011;14:189-93.
Ünal E, Yilmaz E, Özcan A, Işik B, Karakükcü M, Turan C, et al
. Twenty children with non-Wilms renal tumors from a reference center in Central Anatolia, Turkey Turk J Med Sci 2020;50:18-24.
Jimenez RE, Folpe AL, Lapham RL, Ro JY, O'Shea PA, Weiss SW, et al
. Primary Ewing's sarcoma/primitive neuroectodermal tumor of the kidney: A clinicopathologic and immunohistochemical analysis of 11 cases. Am J Surg Pathol 2002;26:320-7.
Bing Z, Zhang P, Tomaszewski JE, Maclennan GT. Primary Ewing sarcoma/primitive neuroectodermal tumor of the kidney. J Urol 2009;181:1341-2.
[Figure 1], [Figure 2]