title: Adrenal collision tumors and their mimics: multimodality imaging findings.
abstract: Adrenal collision tumors (ACTs) refer to coexistence of two adjacent, but histologically distinct neoplasms involving the adrenal gland without histologic admixture at interface. ACTs include adenoma with myelolipoma, adenoma with metastases, hemangioma with adenoma, and adrenocortical carcinoma with myelolipoma. In addition, hemorrhage into a pre-existing adrenal mass can mimic an ACT, and it is important to differentiate these two pathologies. Accurate characterization of ACTs is difficult, but critical, for correct staging of patients with malignancies and to guide percutaneous biopsy. Magnetic resonance imaging (MRI) and multidetector computed tomography imaging techniques may depict different tumor components separately; however, biopsy may be required in selected patients for confirmation. [(18)F]Fluorodeoxyglucose-positron emission tomography (PET) shows increased uptake in the malignant component of ACTs, and guides percutaneous biopsy. Even in patients requiring percutaneous biopsy for a definite diagnosis, imaging findings can help in guiding the appropriate component to be biopsied. Knowledge of imaging findings of different ACTs and their mimics on MRI, computed tomography, and PET help in optimal patient management.
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Venkata S
authors.initials: VS
authors.lastname: Katabathina
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Flaherty
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Ravi
authors.initials: R
authors.lastname: Kaza
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Vijayanadh
authors.initials: V
authors.lastname: Ojili
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Kedar N
authors.initials: KN
authors.lastname: Chintapalli
authors.affiliation: Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Srinivasa R
authors.initials: SR
authors.lastname: Prasad
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D061330:Multidetector Computed Tomography / Q000379:methods; D064847:Multimodal Imaging / Q000379:methods*; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods