Diagnostic Yield and Safety of Cerebellar and Brainstem Parenchymal Biopsy.
OBJECTIVE
We aimed to determine the diagnostic yield and safety of posterior fossa parenchymal biopsy.


METHODS
One-hundred-thirty-six patients who underwent 137 posterior fossa (brainstem or cerebellar) parenchymal biopsies at Mayo Clinic (Rochester, Minnesota, USA) between 1996 and 2009 were identified by chart review. Case histories; radiologic, surgical, and pathologic reports; and safety outcomes were assessed.


RESULTS
Posterior fossa parenchymal biopsies were performed on 78 male and 58 female patients of median age 47 years (interquartile range 28-61). Preoperative clinical diagnosis in the majority of cases was of a malignant neoplasm. Glial neoplasm (51%) was the most common finding followed by lymphoma (7%) and neurosarcoidosis (7%). Normal tissue or nonspecific changes were observed in 28 cases (20%). Three deaths occurred: 2 at the time of biopsy (1%) and 1 due to underlying disease. All deaths occurred in patients who had a cerebellar biopsy. Transient neurologic deficits occurred in 15 patients (11%): worsening of presenting symptoms (4), cardiac arrhythmia (3), vertigo (2), diplopia (2), ataxia (3), seizure (1), decreased consciousness (1), and limb numbness (3). Sustained neurologic deficits occurred in 3 patients: fourth nerve palsy (1), hemiparesis (1), and facial numbness (1).


CONCLUSIONS
The diagnostic yield of posterior fossa parenchymal biopsy in Mayo Clinic patients with diverse pathologies was 80%. The complication rate was 11% with the majority being transient, but 2 deaths were attributed to biopsy. Evaluation of the diagnostic yield and complication rate at individual neurosurgical centers is needed to determine generalizability of these results.
['Tobin|W Oliver|WO|', 'Meyer|Fredric B|FB|', 'Keegan|B Mark|BM|']
D000328:Adult D001706:Biopsy D001933:Brain Stem D020295:Brain Stem Neoplasms D002493:Central Nervous System Diseases D002528:Cerebellar Neoplasms D002531:Cerebellum D003388:Cranial Fossa, Posterior D005260:Female D005910:Glioma D006801:Humans D008223:Lymphoma D008297:Male D008499:Medical Records D008875:Middle Aged D011237:Predictive Value of Tests D012189:Retrospective Studies D012507:Sarcoidosis
Biopsy Posterior fossa Neoplasm Inflammatory changes Sarcoid Spinal cord