Diagnostic yield of stereotactic needle-biopsies of sub-cubic centimeter intracranial lesions.

Background: Stereotactic brain biopsies are widely used for establishing the diagnosis of intracranial lesions. Here we examine whether stereotactic biopsy of smaller brain lesions, defined for this study as being less than 1 cubic centimeter (1 cc) in volume, are associated with lowered diagnostic yield.

Methods: We conducted a retrospective analysis of 267 consecutive patients who underwent stereotactic brain biopsy between 2007 and 2011. Lesion volumes were calculated and were stratified by <1 or >1 cc.

Results: A total of 13 of 246 (5.2%) biopsies for lesions >1 cc resulted in nondiagnostic tissue or an incorrect diagnosis. In contrast, 5 of 21 (23.8%) biopsies for <1 cc lesions yielded nondiagnostic or incorrect diagnosis. Posthoc review of tissue from the <1 cc lesions suggests the neuropathologist's expertise in the handling and analysis of limited specimen as a critical parameter of successful diagnosis. The operative morbidities were low for both the <1 and >1 cc biopsies (0% and 1%, respectively).

Conclusion: This study demonstrates that stereotactic cerebral biopsy of lesions less than a cubic centimeter in volume results in a lower diagnostic yield versus larger lesions (76.2% versus 94.8%). While auxiliary measures may be taken to improve diagnostic yield, these patients may be best managed in a specialized center with experienced stereotactic neurosurgeons and neuropathologists.