Anaplastic lymphoma kinase-positive pulmonary inflammatory myofibroblastic tumor with sarcomatous morphology and distant metastases: An unusual histomorphology and behavior

Inflammatory myofibroblastic tumor (IMT), an intermediate-grade neoplasm of myofibroblastic/fibroblastic differentiation, occurs commonly in children and young adults. It is characterized by anaplastic lymphoma kinase (ALK) gene rearrangement and overexpression of ALK-protein. However, aggressive be...

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Bibliographic Details
Main Authors: Bhawna Sethi, Trupti Pai, Abhishek Allam, Sridhar Epari
Format: Article
Language:English
Published: Wolters Kluwer Medknow Publications 2015-01-01
Series:Indian Journal of Pathology and Microbiology
Subjects:
Online Access:http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2015;volume=58;issue=4;spage=509;epage=512;aulast=Sethi
Description
Summary:Inflammatory myofibroblastic tumor (IMT), an intermediate-grade neoplasm of myofibroblastic/fibroblastic differentiation, occurs commonly in children and young adults. It is characterized by anaplastic lymphoma kinase (ALK) gene rearrangement and overexpression of ALK-protein. However, aggressive behavior is more commonly associated with ALK-negativity rather than ALK-positivity. Pulmonary involvement is most common visceral location and carries minimal potential for distant metastasis. We present a case of 49-year-old female with pulmonary IMT of spindle cell sarcomatous histomorphology. Frequent mitoses and necrosis with characteristic cytoplasmic immunoreactivity for ALK-1 protein and ALK-gene rearrangement on fluorescence in-situ hybridization were noted. This case is unusual for occurrence in higher age-group of fifth decade, sarcomatous histomorphology at presentation (rather than transformation) and metastases to distant sites despite ALK-protein overexpression and gene rearrangement.
ISSN:0377-4929