title: ALK-positive inflammatory myofibroblastic tumor harboring ALK gene rearrangement, occurring after allogeneic stem cell transplant in an adult male.
abstract: Inflammatory myofibroblastic tumor arose as a defined neoplasm from the disparate group of tumors (both neoplastic and inflammatory) originally described as inflammatory pseudotumors. The morphologic features are well described, and 50-60% of cases are associated with fusions of the anaplastic lymphoma kinase (ALK) gene. We describe an inflammatory myofibroblastic tumor in the lower abdominal wall of an adult male, which occurred 88days after he received an allogeneic stem cell transplant for T-lymphoblastic lymphoma, and which was positive for ALK immunohistochemistry and showed ALK gene rearrangement by fluorescence in situ hybridization. Two other cases are reported in the post-stem cell transplant setting, but both occurred in children and did not have molecular analysis performed. The etiology remains unclear, but may be due to immune dysregulation caused by any combination of prior chemotherapy, radiotherapy and immune suppression. These neoplasms should be considered as a rare consequence of allogeneic stem cell transplantation and referral to a specialist sarcoma center for further management may be required.
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London, UK.
authors.forename: Katherine
authors.initials: K
authors.lastname: Vroobel
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Judson
authors.affiliation: Clinical Cytogenetics, Royal Marsden Hospital, Sutton, Surrey, UK.
authors.forename: Melissa
authors.initials: M
authors.lastname: Dainton
authors.affiliation: Clinical Cytogenetics, Royal Marsden Hospital, Sutton, Surrey, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: McCormick
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London, UK.
authors.forename: Cyril
authors.initials: C
authors.lastname: Fisher
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London, UK. Electronic address: khin.thway@rmh.nhs.uk.
authors.forename: Khin
authors.initials: K
authors.lastname: Thway
mesh_terms: D034861:Abdominal Wall / Q000473:pathology*; D000328:Adult; D000077548:Anaplastic Lymphoma Kinase; D015321:Gene Rearrangement; D006104:Granuloma, Plasma Cell / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D033581:Stem Cell Transplantation / Q000009:adverse effects*
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases
keywords: ALK; Fluorescence in situ hybridization; Inflammatory myofibroblastic tumor; Lymphoblastic lymphoma; Molecular analysis; Stem cell transplant