Benign nodal lesions mimicking metastases from pediatric renal neoplasms. A report of the National Wilms' Tumor Study Pathology Center

Douglas A. Weeks, J. Bruce Beckwith, Gary W. Mierau

Research output: Contribution to journalArticle

38 Scopus citations


Regional lymph node status is a key factor in the staging of pediatric renal tumors on the National Wilms' Tumor Study (NWTS). A review of cases entered on the NWTS has uncovered a number of cases where benign lymph node findings were mistaken for metastases. Most frequently, this was due to the presence of complexes of epithelial cells and Tamm-Horsfall protein within nodal sinuses. The epithelial cells were derived from damaged nephrons, usually resulting from obstruction by tumor. Another epithelial pseudometastic lesion, intranodal squamous epithelial cells, was found to originate from metaplastic calyceal urothelium. Benign mesothelial or coelomic inclusions similar to those previously described in pelvic and periaortic lymph nodes of adult females were found in nodes of four patients, including two boys, who are, to our knowledge, the first to be described with this finding. Other sources of confusion included protrusion of lymphoid follicles or germinal centers into nodal sinuses, thick endothelial cells of postcapillary venules mimicking epithelial tubules, nodal megakaryocytes resembling anaplastic nuclear changes, and histiocytic granulomas. Immunocytochemical methods were useful in evaluating some of these phenomena. Recognition of these pseudometastatic lesions is essential in order to avoid unnecessary and potentially hazardous therapeutic intensification.

Original languageEnglish (US)
Pages (from-to)1239-1244
Number of pages6
JournalHuman Pathology
Issue number12
StatePublished - Dec 1990



  • Tamm-Horsfall protein
  • Wilms' tumor
  • benign lymph node inclusions
  • lymph nodes
  • metastasis
  • renal tumors

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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