title: Clinicopathologic study of endolymphatic sac tumor (ELST) and differential diagnosis of papillary tumors located at the cerebellopontine angle.
abstract: We investigated the clinicopathologic features and immunophenotypes of 10 cases of endolymphatic sac tumor (ELST) and compared them with other papillary tumors, including eight cases of choroid plexus papilloma (CPP), three cases of atypical choroid plexus papilloma (ACPP), two cases of papillary ependymoma (PE), three cases of papillary meningioma (PM) and two cases of metastatic carcinoma (MC) the at cerebellopontine angle (CPA). The age at onset of ELST ranged from 13 to 39 years. The male-to-female ratio was 1:1. The clinical presentations were primarily ear-related symptoms. The temporal bones showed extensive destruction. Histologically, the important characteristics for differential diagnosis with CPP, which is most similar to ELST, include the quantity of blood vessels, the nuclei location at apical surface of the papillary, clear cytoplasm cells sometimes with visible vacuoles, psammoma bodies and dura or bone invasion. Immunohistochemistry stains for AE1/AE3, cytokeratin CK)5/6, epithelial membrane antigen, CK8/18, S-100, and synaptophysin are helpful in diagnosis of ELST. In ELST, ultrastructure of uniform 2 μm vesicles in cytoplasm was seen, and gene analysis also showed missense mutation in exon 3. This study indicates that the above histological features combined with immunohistochemistry findings are important for making the correct diagnosis. Gene analysis should be used in patients without medical history to exclude von Hippel-Lindau disease.
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Junmei
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Electron Microscopy, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Guilin
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Shenglin
authors.initials: S
authors.lastname: Yue
authors.affiliation: Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, China National Clinical Research Center for Neurological Diseases, NCRC-ND, Center of Brain Tumor, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Brian Tumor, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D002291:Carcinoma, Papillary / Q000473:pathology*; D002528:Cerebellar Neoplasms / Q000473:pathology*; D002530:Cerebellopontine Angle / Q000473:pathology*; D002648:Child; D003937:Diagnosis, Differential; D004428:Ear Neoplasms / Q000473:pathology*; D004712:Endolymphatic Sac / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020288:Papilloma, Choroid Plexus / Q000473:pathology*; D055815:Young Adult
keywords: cerebellopontine angle; choroid plexus papilloma; endolymphatic sac tumor; immunohistochemistry; temporal bone