Contributed by Dan Hua Zhu MD1, Lin Cai MD1, and Zhe Bao Wu MD, PhD1,2
1 Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China;
2 Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
CLINICAL HISTORY AND IMAGING
A 12-year-old male presented with a 14-month history of progressive weakness of his right arm and leg as well as a deviated mouth. Physical examination revealed a mild right-sided central facial palsy and mild right hemiplegia. MRI axial T1 images showed a mixed and ill-defined signal in left thalamus and cerebral peduncle with mild speckled enhancement (Figure 1a). The anterior horn of the left lateral ventricle and left lateral fissure were enlarged as compared with contralateral side (Figures 1a, 1b). The left cerebral peduncle was significantly smaller than that on the right (Figures 1c, 1d). A stereotactic needle biopsy was performed.
Histopathological examination revealed a neoplasm with the tumor cells arranged in sheeting or nesting patterns. The tumor cells showed translucent or eosinophilic cytoplasm. The round or oval nucleus wee large with deep-staining. In some areas, there were 1-2 large eosinophilic nucleoli. There was also with infiltration by lymphocytes in the tumor(Figure 2a). Immunohistochemical examination showed positive CD117 (Figure 2b) and PLAP (Figure 2c) staining in tumor cells. What is the diagnosis?