Immunohistochemical staining (Figure 2) was positive for vimentin, epithelial membrane antigen (EMA), and smooth muscle actin (SMA) but was negative for glial fibrillary acidic protein (GFAP), leukocyte common antigen (LCA), pan-cytokeratin (PanCK), S100, HMB445, synaptophysin, desmin, CD34, and CD30, ruling out glioma, lymphoma, carcinoma, neural tumors, malignant melanoma, neuroendocrine tumors, rhabdomyosarcoma, vascular and epithelioid sarcomas, and anaplastic large cell lymphoma. Here, GFAP is linked to neuroendocrine neoplasm.