Cytology of chordoid meningioma: a series of five cases with emphasis on differential diagnoses.

BACKGROUND

Chordoid meningioma is a rare meningioma variant characterised by epithelioid cord-like tumour cells in a myxoid stroma. It is classified as grade II (World Health Organization) tumours, as they have a tendency to behave more aggressively than traditional meningiomas and have a greater likelihood of recurrence.

AIMS

To report the features of intraoperative imprint smears of five cases of chordoid meningioma.

METHODS

The intraoperative squash smears were reviewed for cellularity, cellular atypia, mitotic figure, cytoplasmic vacuolation, intranuclear inclusion, presence of a cohesive cord of tumour cells, whorl-like structure, psammoma bodies, chronic inflammatory cells (lymphocytes and plasma cells), background mucin and necrosis.

RESULTS

All cases were of moderate to high cellularity, with cohesive cords of bland tumour cells possessing uniformly round nuclei with smooth nuclear outline, stippled chromatin and small nucleoli, with cytoplasmic vacuolation and chronic inflammatory cells in the background. Intranuclear inclusions (80%) and whorl-like structures (60%) were also common. Necrotic background, psammoma bodies or mitotic figures were consistently absent.

CONCLUSIONS

The cytological features of chordoid mengiomas are distinctive, and intraoperative imprint diagnosis is feasible.