Adult Wilms Tumor: A rare case report from tertiary hospital in Bandung, West Java, Indonesia

Abstract

This case report presents a 38-year-old male patient who presented with a chief complaint of shortness of breath and a palpable mass in his left flank. The patient underwent a radical nephrectomy, and subsequent histopathological examination of the resected specimen, raised a strong suspicion of Adult Wilms Tumor (AWT). To further characterize the tumor and confirm the diagnosis, a comprehensive panel of immunohistochemical stains was performed and concluded as AWT. Wilms tumor primarily affect children, they are exceptionally rare in adults. Currently, no standardized management guidelines exist for AWT. This case report highlighting diagnostic challenges in identifying AWT.

1. Introduction

Wilms tumor, or nephroblastoma, is a malignant embryonal neoplasm originating from nephrogenic blastemal cells, similar to those found in developing kidney histology, often demonstrating divergent differentiation patterns.^1,2 Adult Wilms Tumor (AWT) accounting for only approximately 3 % of all reported Wilms tumor (WT) cases.³ The occurrence of WT in adults is rare, with an incidence of less than 0.2 cases per 1 million people per year.⁴ Owing to its extremely low frequency, this disease is rarely suspected in adult patients, leading to delayed diagnosis and an advanced stage at the time of diagnosis.

The infrequent occurrence of AWT leads to a reduced familiarity with its subtle histological variations. The diagnostic difficulties are further compounded by the fact that the classic triphasic pattern, comprising blastemal, stromal, and epithelial components, commonly observed in childhood WT is not consistently present in adult cases.

The limited literature on AWT presents significant challenges in managing this rare condition. Here, we report the case of a 38-year-old male treated at Hasan Sadikin General Hospital (HSGH), Bandung, Indonesia. The patient, referred from a rural area with limited socioeconomic resources and inadequate health insurance coverage, faced restrictions in accessing comprehensive medical procedures. Initially diagnosed with a common renal tumor, presumed to be renal cell carcinoma, the final diagnosis of WT was confirmed through histopathological examination and immunohistochemistry (IHC) studies.

The lack of distinctive radiographic findings in AWT further complicates the preoperative diagnosis.³ Radiological imaging often reveals a renal mass, but this finding is not specific to WT and is shared by numerous other renal pathologies. Adding to the diagnostic complexity is the absence of persistent renal blastema, a feature typically observed in childhood WT, in the majority of adult cases. This histogenetic difference underscores the need for a more nuanced approach to the diagnosis of AWT, moving beyond the reliance on features characteristic of the pediatric form of the disease.

2. Case presentation

In April 2023, a 38-year-old male presented with a 2-month history of red-colored urine. Physical examination revealed a progressively enlarging, painful mass in the left flank. Urinalysis showed no evidence of cloudy urine or sandy sediments. The patient had a history of hypertension, with an average blood pressure of 140/100 mmHg, and a myocardial infarction in 2021. He was not on any regular medications. Abdominal examination revealed a fixed, well-defined mass in the left abdomen, measuring 10 × 5 cm with regular margins. Minimal tenderness was noted on palpation, and a slight positive ballottement was observed. In May 2023, an abdominal computed tomography (CT) scan revealed findings consistent with clear cell renal cell carcinoma. The imaging also identified multiple enlarged para-aortic lymph nodes and intrapulmonary metastasis, which were corroborated by thoracic scanning. In June 2023, chest radiography confirmed the presence of intrapulmonary metastasis (Fig. 1).

Fig. 1.

Imaging studies findings. A. Abdominal CT from May 2023 revealed a solid mass with necrotic and calcified components, originating expansively from the middle to lower pole of the left kidney (arrow). B. Abdominal CT from April 2024 showing no evidence of a residual kidney mass or intrahepatic metastasis post nephrectomy in July 2023. C. Thoracic x-ray from June 2023 demonstrated lung metastasis (arrowhead). D. Thoracic x-ray from May 2025 (third) revealed larger lung metastasis (arrowhead) compared with the first and the second (April 2024) chest x-ray.

The patient underwent cytoreductive nephrectomy with a pre- and post-surgical diagnosis of a left kidney tumor. Intraoperatively, the left kidney was found to be approximately three times its normal size and adherent to the surrounding tissues, though it remained operable. The left ureter, which appeared normal in size and shape, was also adherent to the surrounding tissues, but was successfully mobilized. Upon dissection of the kidney, a yellow-brown mass measuring 90 × 70 mm was identified, extending from the inferior to the medial pole of the left kidney, as depicted in Fig. 2.

Fig. 2.

Macroscopic features of the kidney from a radical nephrectomy. A. The kidney was approximately 3 times its normal size, with a total weight of 1024.9 g. B. Lamellated kidney showed a large, yellow-greyish lobulated tumor, occupying majority of the nephrectomy specimen.

The kidney specimen was sent to the Department of Pathology for evaluation. Histopathological examination suggested the diagnosis of WT in adults involving the left kidney, as shown in Fig. 3. The differential diagnosis included papillary renal cell carcinoma and rhabdoid tumor of the kidney. Gerota's fascia and perirenal fat were free of tumor involvement; however, there was tumor in the ureter. No evidence of lymphovascular or lymph node invasion was observed. IHC analysis revealed positivity for CD56, EMA, Vimentin, WT1, INI1; partial positivity for CD99; and negativity for CK, SMA, CK7, CK20, and Desmin. These findings confirmed an IHC profile consistent with AWT.

Fig. 3.

Histological examination of the kidney revealed a triphasic pattern characteristic of neoplasm. A. Epithelial component showing tubular pattern (arrow), alongside a stromal component (arrowhead), and a blastemal component (inset)(H&E staining, 100x magnification). B. IHC showed strong nuclear staining for WT-1, 100x and 400x magnification (inset). C. IHC also demonstrated retained INI-1, 100x and 400x magnification (inset).

The patient underwent six cycles of chemotherapy post nephrectomy consisting of ifosfamide, mesna, and etoposide, completing the final cycle in December 2023. The patient's complaints of pain and shortness of breath have diminished, and blood pressure is now more controlled, ranging from 110 to 137 mmHg systolic and 68–84 mmHg diastolic. The patient did not undergo radiotherapy. In May 2024, the patient developed anemia (hemoglobin level of 6.4 g/dL) and received a blood transfusion at HSGH. By late May 2024, the patient was readmitted to HSGH due to a worsening of shortness of breath that had started one day prior. Further chemotherapy was planned. Unfortunately, the patient's urea and creatinine levels were elevated (120.1 mg/dL and 7.92 mg/dL), leading to the cancellation of the planned chemotherapy.

3. Discussion

WT is a malignant embryonal neoplasm derived from nephrogenic blastemal cells that replicates the histology of developing kidneys and often exhibits divergent differentiation patterns.¹ The tumors occurred with equal frequency in both kidneys, and there was a slight female predominance (male-to-female ratio of 0.9:1). The average ages at diagnosis were 37 and 43 months in females.⁵ The incidence in children under 10 is 98 %, although WT can also affect adults.⁵ WT in adults are rare, with an incidence of less than 0.2 cases per 1 million individuals per year.⁵

In this patient, AWT occurred in the left kidney and metastasized to the lungs. The patient's symptoms were consistent with those reported in the literature, primarily hematuria and abdominal pain accompanied by hypertension. Abdominal pain and hematuria are usually accompanied by metastasis (10 % in the pediatric population compared to 30 % in adults), and up to 50 % of cases are in advanced stages (III-V).⁶ As described in the case presentation, imaging initially suggested renal cell carcinoma, highlighting the diagnostic challenge of differentiating AWT from other renal neoplasms, as also noted in the literature.^2,6

Numerous studies have investigated the histopathological features of AWT. While the classic triphasic pattern is observed in many cases, its absence does not definitively exclude the diagnosis. Significant variability exists in the relative proportions of these cellular components between different AWT cases. This histological heterogeneity underscores the limitations of relying solely on H&E staining for diagnosis. The presence of anaplasia, a hallmark of aggressive tumor behavior, is a significant prognostic factor, often associated with poorer outcomes.³ Bilateral disease and tumor recurrence further complicate the clinical picture and affect prognosis. These factors highlight the need for a multifaceted diagnostic approach that goes beyond simple visual assessment of H&E stained sections.

IHC plays a pivotal role in confirming the diagnosis of WT and refining the differential diagnosis. WT1, a WT suppressor gene product, is a frequently employed IHC marker that shows consistent overexpression in WT, both in children and adults.^7,8 However, it's crucial to acknowledge that WT1 overexpression is not entirely specific to WT, and its presence should be interpreted within the context of other clinical and histological findings. Other IHC markers, such as INI1, CD99, and vimentin, can provide valuable supporting evidence, contributing to a more comprehensive diagnostic assessment. The utility of these markers in the specific context of AWT requires further investigation, as their sensitivity and specificity may vary depending on the adult versus pediatric presentation.

The IHC staining procedure employed in this case report followed standard protocols for formalin-fixed, paraffin-embedded tissue sections. The resected nephrectomy specimen was processed using routine histological techniques, including fixation in 10 % neutral buffered formalin, paraffin embedding, sectioning, and deparaffinization. Antigen retrieval methods were employed as needed, depending on the specific antibody used. The IHC staining was performed using a panel of antibodies targeting a range of markers. Each antibody was applied according to the manufacturer's instructions, and the stained sections were visualized using a standard chromogen. This comprehensive IHC panel was selected based on its established utility in distinguishing WT from other renal and extrarenal neoplasms.

The present case highlights the diagnostic challenges inherent in identifying AWT based solely on H&E staining. The rarity of the disease, the histological overlap with other renal neoplasms, and the often incomplete or atypical expression of the classic triphasic pattern contribute to diagnostic difficulties. The case demonstrates the crucial role of IHC in improving diagnostic accuracy, particularly in cases where the H&E findings are ambiguous or inconclusive.

Future research should focus on identifying novel molecular markers that can aid in the diagnosis of AWT, potentially improving diagnostic accuracy and reducing the reliance on IHC. The development of more refined diagnostic algorithms that integrate clinical, radiological, histopathological, and IHC data is also crucial. Larger cohort studies are needed to validate the findings of this case report and to further evaluate the utility of different IHC markers in the diagnosis of AWT. This will also allow for a better understanding of the prognostic significance of specific histological and IHC findings in AWT. This improved understanding will inform treatment strategies and improve patient outcomes.

WT rarely occurs in adults, there is no established standard management for them. Nevertheless, management in AWT follows protocols designed for children.⁶ In 2019, a comparative study on WT published from the National Cancer Database by Saltzman et al. found 2686 cases in children, 91 cases in young adults (16–35 years), and 35 cases in patients over 35 years old. The study reported AWT patiens less frequently received lymph node dissection during surgery, also chemotherapy, and radiotherapy, compared to the pediatric population. The study concluded that the poor prognosis in the adult population can partly be explained by modifiable factors such as inadequate lymph node sampling and low use of adjuvant therapy.⁹

In pediatric WT the standard post-operative chemotherapy is vincristine, actinomycin D, and doxorubicin. In advanced conditions, a combination of cyclophosphamide and etoposide is recommended. WT rarely occurs in adults, therefore no established standard management for adults.⁶ Chemotherapy in AWT follows the recommendations of the pediatric tumor board with consideration of the related patient's condition. This patient was the second reported case of AWT in our hospital over the past five years. Despite not receiving chemotherapy, the first patient demonstrated a favorable outcome.¹⁰ In 2017, a patient in Jakarta, Indonesia was also diagnosed with AWT and treated with ifosfamide, carboplatin, and etoposide for six cycles, resulting in a partial response and excellent functional status.¹¹ Our patient came with a pulmonary metastasis and received ifosfamide, mesna, and etoposide chemotherapy. The combination of ifosfamide and mesna has an advantageous effect of preventing internal hemorrhage. The etoposide has been prescribed for the patient's advanced stage.^12,13

Improvement was observed in the patient. Complaints of pain and shortness of breath have been reduced, and the blood pressure was lower. However, chemotherapy for the patient started more than 30 days after the nephrectomy. According to a study conducted by Reinhard et al., delayed adjuvant therapy after nephrectomy affects patient outcomes.¹⁴ AWT is thought to be responsive to radiotherapy, according to the literature.¹⁵ This patient did not undergo radiotherapy due to socioeconomic limitation. Two years after surgery in May 2025, abdominal CT scan revealed no residual mass in the left kidney and no evidence of intrahepatic metastases. However, thoracic imaging showed persistent intrapulmonary metastases.

4. Conclusion

We present a rare case of AWT. The patient was a 38-year-old male with no history of malignancy. The patient underwent left nephrectomy, and histopathological examination led to a diagnosis of AWT. IHC staining for WT1, INI1, CD56, EMA, Vimentin, and CD99 indicated AWT. Due to lung metastasis, the patient underwent a series of chemotherapies. Approximately one year later, he was readmitted to our hospital because of shortness of breath due to persistent lung metastasis. The patient was scheduled for a second round of chemotherapy; however, it could not proceed due to elevated urea and creatinine levels. Two years follow up revealed no recurrence, despite persistent pulmonary metastasis.

CRediT authorship contribution statement

A. Yantisetiasti: Writing – original draft, Conceptualization. A.T. Sihombing: Writing – review & editing. H.R. Machbub: Writing – original draft.

Consent statement

The authors certify that they have obtained all appropriate patient consent forms. The patient provided written informed consent for the publication of the case details.

Ethics statement

The patient consented to the publication of this case report.

Disclosure

The authors declare that there are no conflicts of interest in this work.

Funding

No funding to declare.