Metanephric adenoma diagnosed on biopsy in an infant: a case report

J Med Case Rep. 2023 Aug 8;17(1):354. doi: 10.1186/s13256-023-04046-1.

Abstract

Background: Metanephric adenoma is a rare benign renal tumor of the kidney, uncommonly observed in children. It is often misdiagnosed preoperatively as a malignant neoplasm, leading to an unnecessary nephrectomy. The challenge is to make the right diagnosis preoperatively and therefore manage it with conservative surgery. We report a case of a child with metanephric adenoma who underwent nephron-sparing surgery.

Case presentation: A renal tumor was discovered fortuitously in an 18-month-old Caucasian girl with several congenital malformations. Investigations showed a 28 × 27 × 27 mm left renal mass centrally located, well defined, nonvascularized, with no calcifications and which compressed the adjacent renal tissue. Furthermore, there were no signs of metastasis. The decision of a multidisciplinary meeting was to perform a computed tomography (CT)-scan-guided biopsy. Histologic examination concluded it was a metanephric adenoma. We performed a left open partial nephrectomy via a flank retroperitoneal incision. The final histopathological examination confirmed the diagnosis. The postoperative course was uneventful.

Conclusion: Preoperative diagnosis of metanephric adenoma is challenging. Because of the high probability of unnecessary radical nephrectomy, preoperative biopsy can be safe and determining to guide a more conservative approach so nephron-sparing surgery can be performed.

Keywords: Conservative surgery; Infant; Metanephric adenoma.

Publication types

  • Case Reports

MeSH terms

  • Adenoma* / diagnostic imaging
  • Adenoma* / surgery
  • Child
  • Female
  • Humans
  • Image-Guided Biopsy
  • Infant
  • Kidney / diagnostic imaging
  • Kidney / pathology
  • Kidney / surgery
  • Kidney Neoplasms* / diagnosis
  • Kidney Neoplasms* / pathology
  • Kidney Neoplasms* / surgery
  • Nephrectomy / methods