Cytogenetic and molecular characterization of a congenital mesoblastic nephroma

A newborn baby boy was diagnosed with the mixed form of congenital mesoblas tic nephroma (CMN) representing both classic and cellular histology feature s in the renal tumor. Additionally, the patient had skin and bone lesions c onsistent with multifocal involvement of a generalized infantile fibromatos is (IFS). Both skin and bone lesions were distinctly different from CMN and did not represent metastasis. The primary tumor cell line (MCH-MN-1), esta blished from the resected right kidney tumor, had a diploid DNA content. Cy togenetic studies revealed deletion on the long arm of chromosome 3 (q21q24 ) and duplication on the short arm of chromosome 11 (p15). MCH-MN-1 cells e xpressed ETV6-NTRK3 gene fusion transcripts, characteristic of cellular and mixed forms of CMNs. The cells had high p21 and low Bax mRNA expression in the reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The hi gh level of proliferative marker (Ki67) mRNA expression correlated well wit h the pluripotent nature of MCH-MN-1 in tissue culture (cell doubling time = 12.4 h). Our results showed that MCH-MN-1 might be a good model cell line for investigations on mesoblastic nephroma.