Teratoid Wilms Tumor: A Patient-Level Systematic Review of the Published Literature

Teratoid Wilms tumor (TWT) is a rare morphological variant of Wilms tumor characterized by extensive heterologous differentiation. Its clinical significance remains uncertain because the available evidence consists predominantly of isolated case reports and small case series. We present a patient-level systematic review of published definite TWT cases.

A systematic review of original reports was performed using PubMed/MEDLINE, Google Scholar, citation tracking, and manual reference screening. Patient-level data were extracted exclusively from original publications and harmonized using predefined coding rules.

Forty-four publications contributed 57 unique patients with definite TWT. Median age at diagnosis was 3.0 years, and 50 patients (87.7%) were pediatric; 47 tumors (82.5%) were renal. Histopathological findings demonstrated marked heterogeneity, with squamous/keratinizing epithelium, adipose tissue, and skeletal/rhabdomyoblastic muscle among the most frequently documented heterologous components. Among 21 patients with evaluable response to neoadjuvant chemotherapy, 17 (81.0%) showed minimal response, poor or no response, or progressive disease. At last follow-up, 35 of 42 patients (83.3%) with evaluable disease status had no evidence of disease, and 41 of 45 patients (91.1%) with evaluable vital status were alive.

TWT is a morphologically heterogeneous tumor in which limited response to neoadjuvant chemotherapy is common but not universal. Complete surgical resection remains central to management, although the biological significance of extensive teratoid differentiation requires further investigation.