Tanycytic ependymoma: two case reports and review of the literature.

Two cases of tanycytic ependymoma are reported, one in a woman aged 33 years and one in a man aged 36 years. The woman presented with lesions at L2 and L3 in the spinal cord and clinical symptoms suggested spinal cord compression, such as movement and sensory dysfunction. The man had a lesion located in the lateral ventricle and presented with headache, vomiting, and impaired vision. Both of these patients developed gradual increases in the intensity of their symptoms over a few months prior to admission. A spinal cord MRI of the woman showed a well-defined, solid cystic mass measuring 1.0 × 6.5 cm at L2 and L3 of the spinal cord. The mass showed low signal intensity on T2-weighted images in the intervertebral disc with equal signal intensity T1-/T2-weighted images. The signal was uniform and enhanced scanning showed a light strengthening of signal. A brain MRI of the man showed a well-defined mass measuring 4 cm in diameter invading the right ventricle. The mass showed low signal intensity on right T1-weighted images and high signal intensity on T2-weighted images. Histopathologically, the tumors were rich with significant and uniform proliferation of long spindle cells, which were arranged in fasciculate and knitted patterns with bipolar and spindled processes focally forming perivascular pseudorosettes. The cell nuclei showed minor pleomorphism. A few tumor cells centered on the vessels resulted in a nuclear-free zone, which was characteristic of ependymoma. Immunohistochemically, the tumor cells were positive for GFAP, EMA, and CD99, but negative for S-100. A review of the cases reported in the literature shows that tanycytic ependymoma occurs more often in the spinal cord. As it can resemble pilocytic astrocytoma and schwannoma, tanycytic ependymoma should be differentially diagnosed to exclude some of the benign spindle cell tumors of the central nervous system. [ABSTRACT FROM AUTHOR]