ALK negative inflammatory myofibroblastic tumor of the orbit: A masquerading entity.

Infl ammatory myofi broblastic tumor is a biologically distinct neoplasm of intermediate grade, which can aff ect every possible tissue of the human body. It is a ‘masquerading tumor’ as the presenting complaints vary with the aff ected site. Occurrence of this tumor as an orbital mass is rare and is challenging for both the clinician as well as the pathologist, due to a varied number of lesions sharing a similar picture clinically and histologically. We discuss a rare case of inflammatory myofibroblastic tumor presenting as an orbital mass and the importance of immunohistochemistry in arriving at the diagnosis, which helps dictate the treatment and prognosis of the patient.

Absence of anaplastic lymphoma kinase-1 expression in inflammatory myofibroblastic tumors of the central nervous system: Does it signify a different nosologic entity from its systemic counterpart.

Background and Aim: Infl ammatory myofi broblastic tumors (IMFTs) are uncommon neoplasms of the central nervous system (CNS) of intermediate grade biologic potential. Anaplastic lymphoma kinase (ALK-1), a diagnostic marker of anaplastic large cell lymphoma, is also expressed in a subset of IMFTs and appears to have prognostic signifi cance. Though, few studies have evaluated expression of ALK-1 in IMFTs of the CNS. This retrospective study was undertaken to evaluate the expression of ALK-1 expression in IMFT of CNS by immunohistochemistry and correlate with the clinical, radiological and pathologic features. Materials and Methods: Five cases diagnosed as IMFT/ infl ammatory pseudotumour/plasma cell granuloma, diagnosed in CNS over 10 year period (1998-2007) were retrieved from the archives of Department of Neuropathology of a tertiary referralcenter. The clinical profi le and imaging features were collected from the case records. Hematoxylin and eosin stained sections were reviewed with immunohistochemistry for smooth muscle actin (SMA), vimentin, desmin, ALK-1, p53, MIB-1, CD68, leukocyte common antigen, CD3, and CD20. Results: All fi ve cases of IMFTs presented as duralbased space occupying or en-plaque lesions. Histologically, four cases had combined plasma cell granuloma-fi brous histiocytoma morphology, and one had fi brous histiocytoma-like morphology. Immunohistochemically, SMA was strongly positive in spindle cell component of the tumors confi rming diagnosis. ALK-1 expression could not be detected by immunohistochemistry in any of the cases. Conclusion: Further studies analyzing ALK-1 gene mutation and rearrangements are required to determine pathogenetic role, if any, in CNS IMFTs.