[A clear cell type meningioma in the upper eyelid ascertained by immunohistochemical examination]

Area of Science:

• Ophthalmology
• Neuropathology
• Oncology

Background:

• Meningiomas are rare tumors originating from meninges.
• Clear cell meningioma is an uncommon subtype with distinct histological features.
• Eyelid involvement by meningioma is exceptionally rare.

Observation:

• A 66-year-old male presented with a slow-growing, well-defined tumor in the left upper eyelid.
• Computed tomography revealed a homogeneous, contrast-enhancing mass.
• Histological examination showed oval cells with clear cytoplasm in streamed and whorl patterns, lacking psammoma bodies or calcification.

Findings:

• Immunohistochemistry revealed positivity for vimentin, epithelial membrane antigen, and protein S-100.
• These markers are characteristic of meningioma cells.
• The histological and immunohistochemical profile confirmed a clear cell meningioma.

Implications:

• Eyelid meningiomas may arise from ectopic arachnoid cells associated with the trigeminal nerve sheath.
• Histological and immunohistochemical variability necessitates careful diagnostic evaluation.
• Accurate diagnosis is crucial for appropriate management and understanding of rare orbital tumors.