MICROSCOPIC DESCRIPTION:
The sections show a variably hypercellular meningioma. A predominant syncytial architecture with areas of fibroblastic meningioma is noted in the sphenoidal wing component (specimens 2 and 3) and this component shows full thickness infiltration of dura and extensive invasion of skeletal muscle. The orbital component (specimen 4) is densely hypercellular and is composed of diffuse sheets of cells with overlapping pleomorphic vesicular nculei, many with conspicuous nucleoli. Moderate numbers of mitotic figures are noted in this component (6/10HPF). No areas of necrosis are identified. There is no evidence of invasion of brain parenchyma. Immunohistochemistry shows patchy moderate expression of PgR in tumour cells. There is weak membrane staining for epithelial membrane antigen (EMA). The topoisomerase labelling index is approximately 15%. The features are of atypical meningioma (WHO Grade II)
5. The section shows that the entire specimen consists of atypical meningioma (WHO Grade II) with features as seen in specimens
DIAGNOSIS:
- 1-4: Sphenoid wing and orbital tumour: Atypical meningioma (WHO Grade II)
- 5: Anterior inferior orbital margin: Atypical meningioma (WHO Grade II)