title: Two cases of ringlike enhancement on MRI mimicking malignant brain tumors.
abstract: The present study was performed to investigate two cases with ringlike enhanced lesions mimicking malignant tumors on magnetic resonance imaging (MRI) and to determine the utility of thallium-201 single-photon emission tomography (201Tl-SPECT) and diffusion-weighted MR imaging (DWI) for differential diagnosis between neoplastic and nonneoplastic lesions. One patient was a 50-year-old man who presented with a right caudate lesion. The 201Tl-SPECT study revealed no uptake in the lesion. Stereotactic biopsy was performed, and pathological findings indicated cerebral infarction. The other patient was a 58-year-old woman who presented with a right frontal lesion with edema. DWI showed a hypointense signal, and the apparent diffusion coefficient (ADC) revealed a hyperintense signal in the lesion. Stereotactic biopsy with endoscopy was performed, and the pathological findings suggested a demyelinating disease. Combined 201Tl-SPECT and DWI studies may be useful for differential diagnosis between neoplastic and nonneoplastic lesions. However, stereotactic biopsy should be performed for the final pathological diagnosis.
authors: Department of Neurological Surgery, School of Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-0012, Japan. ytanaka@wakayama-med.ac.jp
authors: Yoshiyuki
authors: Y
authors: Tanaka
authors: Yuji
authors: Y
authors: Uematsu
authors: Yoshihiro
authors: Y
authors: Owai
authors: Toru
authors: T
authors: Itakura
mesh_terms: D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D005260:Female; D005456:Fluorescent Dyes; D006416:Hematoxylin; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008264:Macrophages / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D013793:Thallium; D016707:Tissue Fixation; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D004396:Coloring Agents; D005456:Fluorescent Dyes; D019275:Radiopharmaceuticals; D013793:Thallium; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin