Crush cytology of a primary intraspinal rhabdoid papillary meningioma: a case report.

BACKGROUND: Both rhabdoid and papillary meningioma are rare variants of meningioma categorized as WHO grade III. Here, we report a rare case of combined rhabdoid papillary meningioma with discussion of its differential intraoperative cytologic diagnoses. CASE: The patient was a 72-year-old female who presented with a huge mass at the cervical spine on MRI. The crush smears showed a radially arranged pattern of elongated tumor cells centered around the vessels, which formed a pseudorosette-like papillary structure, as well as singly scattered large gemistocyte-like rhabdoid cells with distinct cell borders. Rhabdoid cells had eccentrically placed vesicular nuclei with plump, fibrillary-to-hyaline cytoplasm with short broad processes. Nuclei had occasional nuclear inclusions with no nuclear grooves.
CONCLUSION: Rhabdoid papillary meningiomas, encountered less often, should be distinguished from metastatic tumors of rhabdoid or papillary configuration, astrocytomas, ependymomas and atypical teratoid/rhabdoid tumor. Search for eosinophilic hyaline cytoplasm, rather than a fibrillary one, is critical for distinguishing it from other commonly encountered spinal cord tumors in the total absence of meningothelial whorls, like the present case. We also emphasize that the present case is the first case of rhabdoid papillary meningioma with primary manifestation in the spinal cord.