Malignant rhabdoid tumor of the kidney expresses insulin-like growth factor II transcripts.

Insulin-like growth factor II (IGF-II) is thought to play a major role in fetal growth and development. High levels have been demonstrated in blastemal cells of both normal fetal kidney and Wilms' Tumor (WT). In this report, 2 cases of malignant rhabdoid tumor of the kidney (MRTK) were studied to detect the expression of IGF-II mRNA by in situ hybridization using 35S labelled RNA riboprobes. Results showed highly strong and specific IGF-II mRNA expression by tumor cells.