gms | German Medical Science

Objective: Brainstem tumors account for only 2% of all brain tumors in the adult population and in the majority of cases, surgical resection is not possible. The indication of performing a stereotactic biopsy in order to establish a definite diagnosis has been a matter of debate due to the high eloquence of this region. The objective of this study was to characterise the surgical modalities and risks associated with stereotactic biopsy of brainstem lesions. Furthermore, the diagnostic yield of this procedure and the characteristics of pre-operative magnetic resonance imaging (MRI) are analysed.

Method: The medical records of 37 consecutive adult patients who underwent a stereotactic biopsy of a brainstem lesion at our institution were retrospectively analysed.

Results: In 25 patients (68%), the brainstem lesion was targeted through a frontal approach while a suboccipital approach was chosen in 12 patients (32%). A definite histopathologic diagnosis was established in 35 out of 37 patients (94.5%). Histopathologic examination revealed brainstem glioma in 23 patients (low-grade: n=7; high-grade: n=16). Other diagnoses included inflammation (n=4), lymphoma (n=3), metastasis (n=1), abscess (n=1), chordoma (n=1), tuberculoma (n=1), and radiation necrosis (n=1). In two patients (5.4%), no histopathologic diagnosis was established. The surgical mortality was 0%. In three patients (8%), postoperative neurologic deficits occurred which resolved completely during the further course. One patient (2.7%) suffered from permanent abducens palsy postoperatively.

Conclusions: The results of this series add to the growing body of evidence that stereotactic biopsy of brainstem lesions in adults is a safe and effective procedure. The heterogeneous profile of diagnoses underscores that a histopathologic diagnosis should be established prior to initiating treatment protocols.