Sections examined show a benign tumor formed of proliferating meningothelial cells with focal whorling and focal calcifications (psammoma bodies). Cytoplasm is eosinophilic and abundant and cell borders are ill-defined. Tumor cells appear to infiltrate the related bone. No evidence of atypia or malignancy. Picture is consistent with invasive meningioma, WHO grade I. Invasion into bone does NOT change grade.
Scalp mass.
Soft tissue and bone fragments collectively measured 7.5x6.5x2 cm, largest measuring 3.5x3x2 cm.
Scalp amass, excision biopsy: