Fig. 3

Patterns of recurrence by location. Two of the recurred patients (6%) had a recurrence in both the area of brainstem and chiasm (not shown). Recurrences that occurred in the area of the brainstem (n = 16, 46%) had a tendency to compress or infiltrate the brainstem (n = 8, 23%) or occurred in the cerebellopontine angle (n = 4, 11%) or the foramen magnum (n = 3, 9%), while sphenoid sinus infiltration was rare (n = 1, 3%). Recurrences occurring in the area of the chiasm (n = 13, 37%) were highly likely to infiltrate the sphenoid sinus (n = 8, 23%) with only a small percentage of brainstem infiltration (n = 2, 6%) or progression to the frontotemporal brain tissue (n = 3, 9%). There were 6 recurrences (17%) outside the brainstem or chiasm areas, 3 (9%) in the frontotemporal brain, 2 (6%) in the spinal area and one (3%) surgical pathway recurrence in the skull