title: Inflammatory pseudotumor of the pineal region: First reported case.
abstract: Inflammatory pseudotumors originating in the central nervous system (CNS) are quite rare. To the best of our knowledge, the present study reports the first case of a inflammatory pseudotumor that developed in the pineal region, and describes the neuroimaging, morphological and immunohistochemical findings. A 53-year-old male presented with hearing loss that had been apparent for 1 year and blurred vision that had persisted for 10 months. Magnetic resonance imaging (MRI) demonstrated a homogeneously-enhanced mass in the pineal region and obstructive hydrocephalus. A pathological examination revealed that the lesion was comprised predominantly of spindled cells in a collagenous background, with dense infiltrates of small lymphocytes, plasma cells and uninucleated histiocytes. Immunopositivity for cluster of differentiation (CD)138 was noted. Immunohistochemical staining showed that the cells were immunonegative for glial fibrillary acidic protein, S-100, placental alkaline phosphatase, neurofilament and Pit-Oct-Unc class 5 homeobox 1. The Ki-67 labeling index was <5%. The lymphocytic infiltrates consisted of CD3- and CD43-positive T-cells, and CD20- and CD79A-positive B-cells. Plasma cells displayed polytypic reactivity for immunoglobulin κ and λ light chains. Based on the MRI and the morphological and immunohistochemical analysis, a diagnosis of an inflammatory pseudotumor was formed. The patient underwent a surgical resection of the tumor and currently has a good prognosis.
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Ping-Ding
authors.initials: PD
authors.lastname: Kuang
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Qing-Hai
authors.initials: QH
authors.lastname: Li
authors.affiliation: Department of Pathology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Zi-Yu
authors.initials: ZY
authors.lastname: Liu
authors.affiliation: Department of Pathology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Tang
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Dong
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Xiu-Liang
authors.initials: XL
authors.lastname: Zhu
keywords: inflammatory pseudotumor; magnetic resonance imaging; pathology; pineal region; plasma cells