[1503] Inflammatory Pseudotumors of the Central Nervous System
PC Lui, YS Fan, SS Wong, G Wong, TK Chau, GM Tse, Y Cheng, WS Poon, HK Ng. The Chinese University of Hong Kong, Hong Kong, Hong Kong; Queen Mary Hospital, Hong Kong, Hong Kong; Princess Margaret Hospital, Hong Kong, Hong Kong; Prince of Wales Hospital, Hong Kong, Hong Kong; Tseung Kwan O Hospital, Hong Kong, Hong Kong; Pamela Youde Nethersole Eastern Hospital, Hong Kong, Hong Kong
Background: Inflammatory pseudotumor(IPT) is a disease with unsettled pathogenesis. The aim of this study is to investigate ALK-1 protein expression and IgG4-positive plasma cells(PC) in 3 intracranial IPTs.
Design: Three intracranial IPTs and the corresponding clinical information were retrieved from hospital archive.
| Location | Operation | No. of IgG4+ve PC/HPF(40x) |
| Cerebral falx & tentorium | Resection & radiotherapy | 17 |
| Right lateral ventricle | Resection | 46 |
| Right frontal region | Resection | 41 |
Sections were examined under HE and immunohistochemical stainings including ALK-1 and IgG4.
Results: All cases displayed typical histologic features of IPT with dense lymphoplasmacytic infiltrate admixed with bland spindle cells in a collagenous stroma.
All cases exhibited moderate to marked IgG4-positive PC/HPF.
ALK-1 was negative.
Conclusions: ALK expression was absent in all cases and none of them recur. The detection of significant number of IgG4-positive PC in IPTs suggests that a considerable proportion of intracranial IPT may belong to the IgG4-related subgroup. Hence a trial of corticosteroid may be valid to avoid unnecessary risk taking neurosurgical procedures or in cases with incomplete tumor removal.
Category: Neuropathology
Tuesday, March 10, 2009 9:30 AM
Poster Session III # 204, Tuesday Morning