Contributed by Cui-Yun Sun, PhD1,2,3; Shi-Zhu Yu, PhD1,2,3; Qian Wang, PhD1,2,3; Tong-Ling An, MD1,2,3; Yan-Jun Wen, MD1,2,3
1Department of Neuropathology, Tianjin Medical University General Hospital; Tianjin
2Neurological Institute; Key Laboratory of Post-trauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education; Tianjin
3Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China
A 46-year-old woman was admitted to our hospital with chief complaint of numbness of right lower limb lasting 1 year as well as left leg ache lasting 5 months. The symptoms were gradually developing. There was no history of trauma, drug use or any physical exertion. Neurological examination confirmed sense of pain and temperature subsided in left upper limb, left side of body and right lower limb. Radiating pain happened at the left lap and rear waist, and the tendon reflex weakened slightly at left upper limb and right lower limb. A spinal MRI revealed a heterogeneous intensity enhancing 3.0×1.0×1.0cm mass involving T5 through T7 (Figure 1a, b); it was hypointense on T1 (Figure 1c) and hyperintense on T2-weighted sequences (Figure 1d). Short time inversion recovery (STIR) image showed minimal perilesional edema (Figure 1e). The patient subsequently underwent a near total tumour excision via T5-T7 laminectomy approach. Then she underwent craniospinal irradiation and temozolomide chemotherapy. Postoperative follow-up was uneventful with good control in 12 months.
Histopathologically, the tumor was marked by a background, which resembled a fibrillary astrocytoma component and oligodendrocyte-like component. Punctuating the tumor was fairly sharply circumscribed, round to oval islands of a neuropil-like matrix rimmed by small rounded cells. Mature ganglionic cells were not present. Blood vessels with perivascular hyalinization were observed; mitosis and tumor necrosis were lacking, but microvascular proliferation changes was prominent (Fig 2 and Figs 3a-d). By immunohistochemistry, the islands were strongly positive for synaptophysin (Figure 4a) and NSE (Figure 4b). In addition, some of the tumor cell nuclei were stained with NeuN (Figure 4c). The gliomatous component of the tumor readily stained with GFAP antibody (Figure 4d), P53 immunoreactivity was observed in sporadic tumor cell nuclei (Figure 4e). The Ki-67 labeling index was low to moderate, focally reaching up to 7.8% (Figure 4f). FISH was performed on paraffin-embedded tissue with probes localizing to 1p32, 1q42, 19p13 and 19q13 according to the procedure described by Fallon KB et al (3). No evidence of 1p/19q losses was found. What is your diagnosis?