Contributed by Yang Wen-sheng MD, Shao Wei MD, Liu Dan MD, Hu Jun-cheng MD, Lin Zhen MD, Qi Pei-lin MD, Wang Cheng-Feng MD, Ji Tian-hai, MD.
Department of Pathology, Chenggong Hospital, Xiamen University, Xiamen, China and Fuzhou Dongfang Hospital, Xiamen University
CLINICAL HISTORY AND IMAGING STUDIES
A 25-year-old, previously healthy woman presented with a 3-year history of lumbago with radiation to the right lower extremity and was admitted to our hospital. Pain was of mechanical type and responded well to rest. Complete neurological examination was normal. Magnetic resonance imaging (MRI) showed two well-circumscribed isolated intradural masses at levels L2-L3 and S1-S2. One at level L2-L3 measured 3.2 cm in its longest axis. The other extending from S1-S2 measured 2.2 cm in its long axis. Both masses were heterogeneous in T2 and strongly enhanced after gadolinium injection (Figures 1a, 1b,1c). No other lesions were identified elsewhere on craniospinal axis by MRI. Both masses were completely resected. The patient was discharged ten days later. The MRI performed 10 months after surgery showed no recurrence of the tumors.
At the macroscopic level, the formalin-fixed surgical specimen of the two spinal masses consisted of multiple pieces of soft tissue ranging in size from 3.8 cm. They were grey white in color, and smooth.
Microscopically, they had the same histological appearance (Figures 2a, 2b, 2c). There was almost no cytological atypia, mitotic activity or necrosis. Immunohistochemically, the tumor cells were strongly positive for GFAP, vimentin, and S-100 (Figures 2d, 2e). Stains were negative for cytokeratin, epithelial membrane antigen (EMA) and neuro?lament (NF). The Ki-67 (MIB-1) proliferation index was less than 3% (Figure 2f). Periodic Acid-Schiff (PAS) staining was positive in parts of the tumor (Figure 2g). What is the diagnosis?