Clinical Summary

Clinical Summary: This 48 year old woman was previously healthy and presented with 3 months of left sided arm and leg weakness.  CT head followed by MRI showed a 3cm heterogenously enhancing tumour in the right anterior temporal region with significant surrounding edema and mass effect including midline shift and right uncal herniation (see Fig1a,b). The neuroradiologists noted several unusual features including difficulty in determining whether the lesion was extra-axial with candidate brain invasion or intra-axial and superficial, the margins were ill-defined, and the adjacent brain edema was extensive. CT of the chest/abdo/pelvis was negative. She underwent right frontotemporal craniotomy with total resection of the tumour, the histology is enclosed for discussion. Post-operative imaging showed no evidence of residual tumour. Based on the provided pathologic diagnosis she was not offered chemotherapy or radiation therapy and has been followed with serial MRIs q4 months for the past 3 years without evidence of recurrence.

Discussion points

1. What is your DDx of the H&E stained slide?
2. What additional work-up (IHC and molecular testing) would you perform?