Wilms' Tumor in Adults-Conventional and Unconventional Presentations of a Rare Entity with a Review of Literature

Wilms Tumor: An Unexpected Diagnosis in Adult Patients

CONTEXT.—

Wilms tumor (WT) in adult patients is rare and has historically been a diagnostic and therapeutic conundrum, with limited data available in the literature.

OBJECTIVE.—

To provide detailed diagnostic features, molecular profiling, and patient outcomes in a multi-institutional cohort of adult WT patients.

DESIGN.—

We identified and retrospectively examined 4 adult WT cases.

RESULTS.—

Two patients presented with metastatic disease, and diagnoses were made on fine-needle aspiration of their renal masses. The aspirates included malignant primitive-appearing epithelioid cells forming tubular rosettes and necrosis, and cell blocks demonstrated triphasic histology. In the remaining 2 cases, patients presented with localized disease and received a diagnosis on resection, with both patients demonstrating an epithelial-predominant morphology. Tumor cells in all cases were patchy variable positive for PAX8 and WT1 immunohistochemistry. Next-generation sequencing identified alterations previously reported in pediatric WT in 3 of 4 cases, including mutations in ASXL1 (2 of 4), WT1 (1 of 4), and the TERT promoter (1 of 4), as well as 1q gains (1 of 4); 1 case showed no alterations. Three patients were treated with pediatric chemotherapy protocols; during follow-up (range, 26-60 months), 1 patient died of disease.

CONCLUSIONS.—

WT is an unexpected and difficult entity to diagnose in adults and should be considered when faced with a primitive-appearing renal or metastatic tumor. Molecular testing may help exclude other possibilities but may not be sensitive or specific because of the relatively large number of driver mutations reported in WT.

Clinical value of ultrasound in adult Wilms' tumor patient with uremia: A case report and literature review

RATIONALE

Wilms' tumor (WT) is the most common pediatric kidney malignancy and is rarely found in adults. Nonspecific clinical symptoms and imaging features often lead to delayed diagnosis or misdiagnosis of adult WT, resulting in poor clinical outcomes. Ultrasound (US), as an efficient and noninvasive examination method, has been widely used in clinical diagnosis and treatment. Therefore, various US evidence is meaningful to improve understanding of adult WT characteristics in ultrasound.

PATIENT CONCERNS

A 45-year-old female patient with uremia (regular hemodialysis for 13 years) with painless gross hematuria was diagnosed with a right kidney tumor penetrating to the lung. Preoperatively, B-mode ultrasonography showed an ill-defined hyperechoic mass in the right kidney, which revealed an unclear border, uneven internal echoes, and calcification. Besides, the internal blood flow signal of the tumor was detected. Contrast-enhanced ultrasound (CEUS) showed an uneven hyper-enhancement in the tumor ("fast in and slow out"). Contrast-enhanced computed tomography of the kidney indicated a similar result as the CEUS. Moreover, the chest CT identified multiple pulmonary metastatic nodules.

DIAGNOSES

An ultrasound-guided percutaneous core needle biopsy of the tumor proceeded to make a definite diagnosis of adult WT (epithelial type).

INTERVENTIONS

The patient was treated with tislelizumab.

OUTCOMES

No progress was found to date.

LESSONS

We report the first case in which CEUS was performed in an adult WT patient with uremia and multiple pulmonary metastases. The features obtained by the US can help in the diagnosis of adult WT and direct further diagnostic procedures.

Asymptomatic adult Wilms' tumor: A case report

Wilms' tumor, also called nephroblastoma, is an extremely uncommon kidney tumor of adulthood. We reported a adult man with a left kidney mass diagnosed as Wilms' tumor.

Case presentation: A 25-year-old man was hospitalized due to injury of the anterior cruciate ligament of the right knee. Preoperative imaging accidentally revealed a mass measuring 53 × 46 mm involving the middle and lower segments of the left kidney without evidence supporting the invasion of the surrounding structures or metastasis. The patient didn't show any symptom commonly occurred in Wilms' tumor, such as flank pain or hematuria. After nephrectomy, the diagnosis of adult Wilms' tumor was confirmed based on the tumor morphology and immunohistochemical findings.

Conclusion: In adult patients without any clinical manifestations or favorable imaging findings for low-stage renal cell carcinoma, the diagnosis of Wilms' tumor should be taken into consideration.

Adult Wilms Tumor: Genetic Evidence of Origin of a Subset of Cases From Metanephric Adenoma

The genetics of nephroblastoma (Wilms tumor) occurring in adults is largely unknown, as studies have largely been limited to isolated case reports. We, therefore, studied 14 adult Wilms tumors for genetic alterations, using expanded targeted sequencing on 11 cases. The patients ranged from 17 to 46 years of age (mean and median, 31 y), and there were 8 males and 6 females. Five Wilms tumors harbored BRAF V600E mutations. All of these had better-differentiated areas identical to metanephric adenoma, as has previously been described. In 3 such cases, microdissection studies revealed that the BRAF V600E mutation was present in both the metanephric adenoma and Wilms tumor areas; however, additional genetic alterations (including TERT promoter mutations in 2 cases, ASLX1/ATR mutations in 1 other case) were limited to the Wilms tumor component. These findings suggest that the Wilms tumor developed from the metanephric adenoma. Other adult Wilms tumors harbored genetic alterations previously reported in the more common pediatric Wilms tumors, including WT1 mutations (2 cases), ASLX1 mutations (3 additional cases), NSD2 mutation (1 additional case), and 11p loss (3 cases). In summary, a significant subset of adult Wilms tumors (specifically those of epithelial type with differentiated areas) harbor targetable BRAF V600E mutations and appear to arise from metanephric adenomas as a consequence of additional acquired genetic alterations. Other adult Wilms tumors often harbor genetic alterations found in their more common pediatric counterparts, suggesting at least some similarities in their pathogenesis.