Metastatic seeding of the stereotactic biopsy tract in glioblastoma multiforme: case report and review of the literature

Objective and importance. The first case was recently reported of tumor seeding by glioblastoma multiforme (GBM) after stereotactic biopsy. This occurred despite radiosurgical treatment of the lesion post-biopsy. We report the first case of metastatic seeding along the needle biopsy tract of a GBM in which the tract was within the treatment field of subsequent fractionated radiation therapy. Clinical presentation. A 56-year-old man presented with left-sided focal motor seizures. An MRI showed an enhancing right cingulate gyrus lesion. Intervention. A stereotactic biopsy of the lesion disclosed GBM. Radiation therapy was begun 25 days after biopsy and was completed 39 days thereafter. The biopsy tract received a minimum of 60 Gy. Subsequent magnetic resonance scanning showed the lesion to have doubled in size and evidence of enhancement along the biopsy tract. At surgery, specimens obtained from the biopsy tract, as determined using surgical navigation, revealed GBM. Conclusion. Seeding of the biopsy tract, radioresistance and the time interval until radiotherapy are the most likely explanations for tumor growth along the biopsy tract in this case. Consideration should be given for an early start to radiotherapy among those who undergo stereotactic biopsy for GBM. Further research will allow one to determine the radiosensitivity of these tumors and determine which patients may benefit from a radiosurgical or fractionated radiotherapy boost to the biopsy tract.