Question 1431

{"accessible":false,"alternatives":[{"id":7134,"text":"nephroblastoma"},{"id":7135,"text":"neuroblastoma"},{"id":7131,"text":"renal abscess"},{"id":7132,"text":"renal angiomyolipoma"},{"id":7133,"text":"renal cell carcinoma"}],"archived":false,"correctAlternativeId":7134,"explanation":"\u003cp\u003eThis is a nephroblastoma, more commonly called a Wilms tumor. Wilms tumors are the most common renal mass seen in the pediatric population, accounting for approximately 85% of cases. The ‘claw sign’ is a useful imaging finding that can indicate a mass is arising from a structure rather than adjacent to it. Calcification is much more common in neuroblastoma than Wilms tumor (approximately 90% in neuroblastoma, 15% in Wilms tumor) but the description is of a renal mass, not a suprarenal mass.\u003c/p\u003e\u003cp\u003eA well patient is unlikely to present with an 8.2 cm renal abscess. An angiomyolipoma would be hyperechoic on ultrasound, is unlikely to be this large or present in this manner.\u003c/p\u003e\u003cp\u003eRenal cell carcinoma is very uncommon in childhood although would be a possibility in an older patient.\u003c/p\u003e\u003cp\u003eNeuroblastomas are tumors of neuroblastic origin and most commonly arise from the adrenal gland, these would not demonstrate a ‘claw sign’ with the kidney but may indent it instead.\u003c/p\u003e","id":1431,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/1431","nextQuestionPath":null,"relatedArticles":[{"id":1722,"title":"Neuroblastoma","link":"/articles/neuroblastoma?lang=us"},{"id":6220,"title":"Renal abscess","link":"/articles/renal-abscess?lang=us"},{"id":8152,"title":"Wilms tumor","link":"/articles/wilms-tumour?lang=us"},{"id":7534,"title":"Renal cell carcinoma","link":"/articles/renal-cell-carcinoma-1?lang=us"},{"id":899,"title":"Renal angiomyolipoma","link":"/articles/renal-angiomyolipoma?lang=us"}],"alsoUsedIn":[],"stem":"\u003cp\u003eA 4-year-old-boy presents with a painless right-sided abdominal mass. He is otherwise well. On ultrasound examination, there is an 8.2 cm diameter heterogeneous mass, with a ‘claw sign’ demonstrated in relation to the upper pole of the kidney. The lesion contains a number of cystic areas and a few small areas of calcification. What is the most likely diagnosis?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/1431"}],"attemptsPercentages":[{"alternativeId":"7133","percentage":6},{"alternativeId":"7131","percentage":2},{"alternativeId":"7132","percentage":4},{"alternativeId":"7135","percentage":12},{"alternativeId":"7134","percentage":76}],"promptToLogin":false,"questionManager":false,"articleId":"claw-sign-mass"}