Primary renal neuroblastoma with metastasis and matrix metalloproteinase-14 expression

We herein report the rare case of a 4-year-5-month-old boy who presented with primary renal neuroblastoma. The patient developed repeated lung and liver metastatic recurrences, but, following a combination of chemotherapy, radiation therapy and aggressive surgical resection, the patient is now in remission. To investigate the pathogenesis of lung metastasis, immunohistochemistry was performed for matrix metalloproteinase-9 and -14 (MMP-9 and MMP-14), molecular markers of invasion, metastasis and angiogenesis in neuroblastoma. In the present case, MMP-9 expression was not observed, but MMP-14 expression was detected in the primary lesion and was more highly expressed in the metastatic lesion compared with the primary one. Given the MMP-14 staining in other cases, expression of MMP-14 may be associated with the aggressiveness of the tumor. This suggests that selected clones with high MMP-14 expression in the primary tumor might metastasize and form MMP-14-rich lesions.