Tumor progression in DICER1-mutated cystic nephroma-witnessing the genesis of anaplastic sarcoma of the kidney

Hum Pathol. 2016 Jul;53:114-20. doi: 10.1016/j.humpath.2016.03.002. Epub 2016 Mar 29.


We report a 7-month-old female infant with a multicystic left renal tumor having histologic features predominantly of a cystic nephroma, but with microscopic cellular foci which contained atypical mitotic figures and anaplastic nuclei. Immunohistochemistry showed strong p53 reactivity in the anaplastic region. DICER1 sequencing confirmed 2 mutations: germ line mutation c.2450delC and c.5438A>G somatic within the tumor. Despite an initial consideration of cystic partially differentiated nephroblastoma, the presence of anaplasia ruled that possibility out, as this is not an acceptable feature for that diagnosis. Moreover, the germ line DICER1 mutation prompted consideration that this case represents a unique "nascent" anaplastic sarcoma of kidney, and further immunohistochemical workup demonstrated cytoplasmic, but no nuclear WT-1 reactivity in the cellular foci. The importance of meticulous sampling of cystic lesions is highlighted by this unprecedented case, which lends support to the recent recognition of anaplastic sarcoma of kidney as a DICER1-associated cancer.

Keywords: Anaplastic sarcoma; Cystic nephroma; Germline mutation; Kidney DICER1.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / genetics*
  • DEAD-box RNA Helicases / genetics*
  • DNA Mutational Analysis
  • Female
  • Genetic Predisposition to Disease
  • Germ-Line Mutation*
  • Humans
  • Immunohistochemistry
  • Infant
  • Kidney Neoplasms / chemistry
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / pathology
  • Neoplasms, Cystic, Mucinous, and Serous / chemistry
  • Neoplasms, Cystic, Mucinous, and Serous / genetics*
  • Neoplasms, Cystic, Mucinous, and Serous / pathology
  • Phenotype
  • Ribonuclease III / genetics*
  • Sarcoma / chemistry
  • Sarcoma / genetics*
  • Sarcoma / pathology
  • Tumor Suppressor Protein p53 / analysis
  • Tumor Suppressor Protein p53 / genetics
  • WT1 Proteins / analysis


  • Biomarkers, Tumor
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • WT1 Proteins
  • WT1 protein, human
  • DICER1 protein, human
  • Ribonuclease III
  • DEAD-box RNA Helicases