title: Anaplastic lymphoma kinase-positive pulmonary inflammatory myofibroblastic tumor with sarcomatous morphology and distant metastases: An unusual histomorphology and behavior.
abstract: 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.
authors.forename: Bhawna
authors.initials: B
authors.lastname: Sethi
authors.forename: Trupti
authors.initials: T
authors.lastname: Pai
authors.forename: Abhishek
authors.initials: A
authors.lastname: Allam
authors.affiliation: Department of Pathology, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Epari
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D005260:Female; D005354:Fibrosarcoma / Q000175:diagnosis* / Q000473:pathology; D015321:Gene Rearrangement; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008853:Microscopy; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000175:diagnosis* / Q000473:pathology; D009379:Neoplasms, Muscle Tissue / Q000175:diagnosis* / Q000473:pathology; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis*
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases