title: Histiocyte-rich xanthomatous pseudotumor mimicking relapse on positron emission tomography imaging in an adolescent with primary mediastinal diffuse large B-cell lymphoma.
abstract: Inflammatory pseudotumors (IPTs) are rare, enigmatic lesions that may develop as a late manifestation of a reparative process. We describe the case of a teenager with primary mediastinal subtype of diffuse large B-cell lymphoma who developed an IPT at the site of the original lymphoma, mimicking relapse of disease on positron emission tomography/computed tomography imaging. This is the first report of IPT in a teenager with mediastinal lymphoma. This case is an important reminder of the limitations of positron emission tomography/computed tomography imaging in patients with lymphoma and stresses the importance of histologic confirmation of suspected treatment failure or relapse.
authors.affiliation: Department of Oncology, St Jude Children's Research Hospital, Memphis, TN, USA. mario.otto@stjude.org
authors.forename: Mario
authors.initials: M
authors.lastname: Otto
authors.forename: Barry L
authors.initials: BL
authors.lastname: Shulkin
authors.forename: Mondira
authors.initials: M
authors.lastname: Kundu
authors.forename: John T
authors.initials: JT
authors.lastname: Sandlund
authors.forename: Scott E
authors.initials: SE
authors.lastname: Snyder
authors.forename: Monika L
authors.initials: ML
authors.lastname: Metzger
mesh_terms: D000293:Adolescent; D005260:Female; D019788:Fluorodeoxyglucose F18; D015614:Histiocytosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D008479:Mediastinal Neoplasms / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D014973:Xanthomatosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18