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Donut sign: a unique radiological sign of cerebral metastasis in malignant mesothelioma
  1. OreOluwa Adeyinka1,
  2. Ashraf Dower2 and
  3. Yingda Li3,4
  1. 1Nepean Hospital, Penrith, New South Wales, Australia
  2. 2Neurosurgery, Nepean Hospital, Penrith, New South Wales, Australia
  3. 3Neurosurgery, Westmead Hospital, Westmead, New South Wales, Australia
  4. 4Westmead Clinical School, The University of Sydney Sydney Medical School, Sydney, New South Wales, Australia
  1. Correspondence to Dr OreOluwa Adeyinka; ore.adeyinka{at}


A man in his 70s presented to the emergency department with a 3-day history of confusion and right-facial droop. He was diagnosed with stage IIIB (T4N2M0) malignant mesothelioma 6 months previously for which he was being given palliative chemotherapy. An MRI of the brain demonstrated a left parietal cerebral metastasis with unique radiological characteristics termed ‘donut sign’. He underwent a craniotomy and complete macroscopic resection of the lesion with a good postoperative outcome. Mesothelioma cerebral metastases are a rarely reported clinical entity, with only a handful of case reports and case series available. On MRI they often demonstrate a distinctive thick-walled lesion, termed ‘donut sign’, that may be indicative of the diagnosis. Furthermore, case autopsy series suggest these metastases may be underdiagnosed in the clinical setting due to the dismal prognosis. With newer and more effective neoplastic treatment strategies emerging, there may be a rising incidence of central nervous system metastases in the future.

  • Neuroimaging
  • Neurooncology
  • Neurosurgery

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  • Contributors OA contributed by acquiring the patient’s electronic medical records, surgical notes and pathology reports to draft the body of the manuscript and contributed to the literature review required for the background portion of the manuscript. YL was responsible for conception and design of the case report as well as final approval of version submitted. AD was involved in editing drafts of the manuscript and literature review necessary for the development of the discussion.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.