A high-grade glioma with SOS1 amplification.

The molecular alterations underlying progression of low-grade glial/glioneuronal tumors remain to be elucidated. We present a case of a 56-year-old male with an enhancing left temporal lobe tumor. Histology revealed a high-grade glioma adjacent to a low-grade glioneuronal component with abundant Rosenthal fibers, focal eosinophilic granular bodies, and CD34-positive neurons. The tumor was negative for IDH1 (R132H), BRAF-V600E, and the KIAA1549-BRAF fusion. Comparative genomic hybridization detected a large amplification (> 15 copies) of the Son of Sevenless 1 (SOS1) gene, a component of the MAPK pathway. Although activating mutations in the MAPK pathway occur frequently in gliomas and glioneuronal tumors, SOS1 gene amplification has not been reported previously. This case indicates another potential mechanism for MAPK activation in glial tumors.

Factors Predicting the Need for Surgery of the Opposite Side After Unilateral Evacuation of Bilateral Chronic Subdural Hematomas.

BACKGROUND: Patients with bilateral chronic subdural hematoma (bCSDH) undergo unilateral evacuation for the large or symptomatic side because the contralateral hematoma is either small or asymptomatic. However, the contralateral hematoma may subsequently grow and require evacuation. OBJECTIVE: To characterize factors that predict contralateral hematoma growth and need for evacuation. METHODS: A retrospective study on 128 surgically treated bCSDHs. RESULTS: Fifty-one and 77 were bilaterally and unilaterally evacuated, respectively. Glasgow Coma Scale was lower and midline shift was higher in those evacuated unilaterally compared to those evacuated bilaterally. Hematoma size was a significant determinant of decision for unilateral vs bilateral evacuation. The contralateral side needed evacuation at a later stage in 7 cases (9.1%). There was no significant difference in terms of reoperation rate between those evacuated unilaterally and bilaterally. Greater contralateral hematoma thickness on the first postoperative day computed tomography (CT) and more postoperative midline shift reversal had higher rates of operation in the opposite side. There was no difference between the daily pace of hematoma decrease in the operated and nonoperated sides (0.7% decrease per day vs 0.9% for the operated and nonoperated sides, respectively). CONCLUSION: Results of this study show that most bCSDHs evacuated unilaterally do not experience growth in the nonoperated side and unilateral evacuation results in hematoma resolution for both sides in most cases. Hematoma thickness on the opposite side on the first postoperative day CT and amount of midline shift reversal after surgery are the most important factors predicting the need for surgery on the opposite side.