Secondary tumor formation after stereotactic biopsy for intracerebral metastatic disease.

Background: There are only a few published cases of iatrogenic tumor seeding and distant neoplastic growth along the path of the cannula after stereotactic biopsy.

Case Description: We report the case of a female patient with a solitary lung cancer metastasis in the left parietal brain lobe. The tumor was stereotactically biopsied and treated by radiosurgery. One month after the initial biopsy, a smaller de novo tumor mass located along the track of the stereotactic cannula was detected by contrast-enhanced MRI. The spatial location of this neoplastic nodule and the short time before development of a macroscopic lesion seemed to confirm iatrogenic tumor cell spread due to the stereotactic procedure.

Conclusion: Our findings and the reviewed literature suggest that this complication is rare. Nevertheless, neurosurgeons should be aware of the potential risk and, if necessary, should be able to modify the technical procedure and the adjuvant treatment.