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.
Department of Neurology, College of Medicine, Mayo Clinic, Rochester, Minnesota, USA.
W Oliver
WO
Tobin
Department of Neurosurgery, College of Medicine, Mayo Clinic, Rochester, Minnesota, USA.
Fredric B
FB
Meyer
Department of Neurology, College of Medicine, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: keegan.bmark@mayo.edu.
B Mark
BM
Keegan
D000328:Adult; D001706:Biopsy / Q000009:adverse effects; D001933:Brain Stem / Q000473:pathology*; D020295:Brain Stem Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D002493:Central Nervous System Diseases / Q000175:diagnosis; D002528:Cerebellar Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D002531:Cerebellum / Q000473:pathology*; D003388:Cranial Fossa, Posterior / Q000473:pathology; D005260:Female; D005910:Glioma / Q000175:diagnosis; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012507:Sarcoidosis / Q000175:diagnosis
Biopsy; Inflammatory changes; Neoplasm; Posterior fossa; Sarcoid; Spinal cord