CASE 11 D.W. Ng1, G. Dalgliesh2, R.L. Barnhill1 and H.V. Vinters1 (Division of Neuropathology, Department of Pathology, University of California Los Angeles, Los Angeles, California)1 (Department of Pathology, University of California Los Angeles, Los Angeles, California)2 Clinical history: A 43 year old woman, who was otherwise healthy, presented to emergent care with newonset, severe headaches, nausea and vomiting. Her other medical history included gestational diabetes and pregnancy-induced hypertension which resolved with delivery of her child. History of previous malignancy was negative. Review of systems was unremarkable. While in emergent care, head CT identified a left frontal temporal duralbased mass that prompted an outpatient neurosurgery referral. In detail, Brain MRI showed a 3.2 cm extra-axial mass with dural tails located over the left frontal operculum. The mass showed heterogeneous enhancement, and mass effect, including minimal narrowing of the left lateral ventricle and minimal mid-line shift to the right by 2 mm. Gross total resection was performed without complication. The postoperative diagnosis was meningioma. Post-operative imaging at 4 months showed dural thickening and enhancement of the meninges subjacent to the craniotomy flap, which was interpreted as reactive changes. Materials submitted: One digital H&E stained section Questions: Diagnosis? Classification? Further molecular testing?