Left Atrial Metastasis of Wilms Tumour in Abeokuta, Nigeria: A Case Report

Background: Wilms tumor (WT) is the most common renal malignancy, and also the second most common intra-abdominal cancer of childhood globally. It typically presents as an abdominal mass. In low-and-middle-income countries, however, patients tend to present with advanced disease which has extended beyond the renal bed. Evidence of metastasis has been reported in about 12% of WT cases, with the lungs being the most common site in more than 80% of advanced cases. Less frequently disease may spread to the liver, bones, brain, and rarely the heart.

Objective: To highlight left atrial metastasis as a rare complication of WT, as well as, emphasize the importance of echocardiography as a component of routine evaluation of suspected cases of WT.

Methods: We present a 5-year-old female who presented with a three-year history of left-sided abdominal swelling, one-year history of weight loss and recurrent abdominal pain, and three-week history of cough.

Results: Abdominopelvic CT scan and ultrasound were both in keeping with left nephroblastoma. Echocardiogram revealed a left intra-atrial mass measuring 14mm X 17mm.

Treatment/Outcome

She was diagnosed with Stage IV nephroblastoma, commenced on neo-adjuvant chemotherapy. A repeat echocardiography was planned after the completion of the neo-adjuvant chemotherapy schedule. She however died during the 4th week of treatment.

Discussion

Wilms tumour has been reported to invade vascular structures with consequent extension to the right atrium and ventricle. Left atrial involvement in WT is a rare but documented complication of the disease, and could be an asymptomatic, incidental finding as it occurred in the index case.

Conclusion and Recommendations

Wilms tumour patients should have echocardiography done as part of their routine evaluation to provide baseline information about cardiac function prior to the commencement of potentially cardiotoxic medications, and also to screen for intra-cardiac extension of the disease.