TY - JOUR T1 - Discrepancy in the Ki67 labeling index of brain and orbital metastatic lesions from gastrointestinal neuroendocrine tumors: A case report JO - Neurocirugía (English edition) T2 - AU - Matsuo,Satoshi AU - Amano,Toshiyuki AU - Miyamatsu,Yuichiro AU - Hayashi,Daisuke AU - Yamashita,Sojiro AU - Momosaki,Seiya AU - Kawabe,Ken AU - Nakamizo,Akira SN - 25298496 M3 - 10.1016/j.neucie.2021.04.010 DO - 10.1016/j.neucie.2021.04.010 UR - https://www.revistaneurocirugia.com/en-discrepancy-in-ki67-labeling-index-articulo-S2529849622000594 AB - Proliferative activity examined by Ki67 labeling index (LI) plays pivotal role for managing gastrointestinal neuroendocrine tumor (GI-NET). Few reports indicated the intra-patient heterogeneity of Ki67-LI among metastatic tumor sites. We report a case of brain and orbital metastases from GI-NET that showed discrepancy of the Ki67-LI. A 71 year-old woman who was diagnosed as GI-NET with liver and bone metastases and performed medical therapy, had headache, right exophthalmos, and pain of right eye and was referred to our department. Magnetic resonance image revealed that tumors in the left occipital region and right orbit. We diagnosed as metastatic brain and orbital tumors from GI-NET. Surgical removal of both symptomatic lesions was performed and the diagnosis was pathologically confirmed. Immunohistochemical studies revealed the discrepancy of the Ki67-LI of the lesions (brain tumor: 8% versus orbital tumor: 22%). Sampling of multiple metastatic sites may prevent underestimate tumor proliferative activity. ER -