title: Significance of the "maturation" of metastases from Wilms' tumor after therapy.
abstract: Several metastatic nodules were discovered in the lungs of a 4-year-old boy two years after surgical excision of Wilms' tumor with subsequent chemotherapy and local irradiation. All these metastatic nodules were composed of differentiated mesenchymal elements similar to those encountered in the primary neoplasm. Similar "mature" metastases have been observed by pathologists in other tumors of embryonic origin. Review of available literature and clinical and experimental data supports the notion that "reversion" of malignant cells into phenotypically benign counterparts may take place spontaneously or under the influence of environmental factors. Anticancer agents (cytostatics, radiation) selectively destroy the more anaplastic cells present in a malignant tumor (or its metastatic implants), thus allowing the "benign" revertants to predominate. Although such lesions are benign-appearing, it is recommended that they be completely excised; however, but further chemo- or radiotherapy may not be necessary.
mesh_terms: D002675:Child, Preschool; D003131:Combined Modality Therapy; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D008175:Lung Neoplasms / Q000556:secondary*; D008297:Male; D009396:Wilms Tumor / Q000556:secondary / Q000601:surgery*