Grade I Meningioma in a cadaver – A case report

Introduction

Meningioma is a benign tumor, arising from the meninges of the brain and the spinal cord. WHO has classified Meningioma into three grades, grade I is common, grade II is atypical and grade III is malignant Meningiomas.1, 2 Aapproximately 50% of all benign brain tumors are meningiomas.1, 3, 4 Meningioma originates from the meninges of the brain and the spinal cord.2 Meningiomas are commonly benign and are grade 1type. Meningiomas are associated with certain conditions and risk factors such as, obesity, alcoholism, exposure to radiation, radiotherapy, hormone replacement therapy, use of oral contraceptive pills, breast cancer. Higher incidence are in females due to hormonal factors.4, 2, 5 Meningioma is common in old age.1, 6, 7 Its higher incidence in African-American with female to male ratio being 2.27:1.1, 2

Case Presentation

We found this tumor during the routine dissection of brain, from the aged male cadaver. We observed a small round mass situated on the jugum spheniodale, apart of sphenoid bone in the anterior cranial fossa.

Figure 1

Arrow showing site of the tumor

First it was observed on bone, then we noticed a small depressed area on inferior surface of frontal lobe. We correlated size of tumor mass and size of depressed area on brain. Depression of the same size on the orbital surface of the frontal lobe near the medial margin in the gyrus rectus was observed. The depression was encapsulated and the mass was present in that depression.

Figure 2

Arrow showing tumor mass

A tumor measuring 1.3 cm in length, 1.3 cm in breadth and 1.2cm in height was found. Tumor mass was excised and processed with routine histology technique and slides were prepared and stained with haematoxylin and eosin stain.

Figure 3

Arrows showing blood vessels

Figure 4

Arrows showing psammoma bodies and whorl pattern of meningo epithelial cells

Figure 5

A number of tumor cells, blood vessels, fibrous tissue, and septal plasma bodies, as displayed in Figure 3, Figure 4, Figure 5. The discussion of the said tumor with the pathology Dept. lead to the diagnosis of this mass as Grade 1 Meningioma

Discussion

According to histological structures, WHO has classified meningioma into 3 grades.2

More than 80% of Meningiomas, are of grade I type containing these histological variantions.2, 8

Out of these we have observed Psammoma bodies which are concentric lamellated calcified structues commonly observed in meningioma grade I as shown in Figure 3.

In Grade 2 following atypical lesion present3, 2

In Grade 3 malignant legions are present 8

In Cystic Meningiomas cysts are present within or around tumor in 4-7% of meningioma.9

Meningioma en plague (MEP) is another type of meningioma shows diffuse and extensive involvement of dura mater, usually with extracranial extension into the bones, orbit, dura and the soft tissue. MEP is classified as grade 1by WHO.10, 11 On histopathological study of these hyperostosis in MEP usually contains whorls of Meningothelial cells. Hyperostosis is present in 13 - 49% of MEP cases.11, 12

Radiation Induced Meningiomas (RIM) are tumors that develop as a complication from exposure to radiation.

Ossified Meningioma is are tumor characterized by complete ossification or calcification. Ossification differs from these is seen in Psammomatous Meningioma.13

We diagnosed the Meningioma as Grade 1 based on, its microscopic study and its site, in the microscopic study Meningothelial cells and whorl patterned psammoma bodies were observed. Hence, it is a Psammomatous type of Grade 1 Meningioma.

Conclusion

Source of Funding

None.

Conflict of Interest

None.