Diffuse pulmonary uptake on FDG-PET with normal CT diagnosed as intravascular large B-cell lymphoma: a case report and a discussion of the causes of diffuse FDG uptake in the lungs.

A 71-year-old woman was admitted to our hospital with asthenia, weight loss, fever, cognitive impairment and shortness of breath. Physical examination showed hemiparesis and cerebellar ataxia. There was no superficial lymphadenopathy. Blood tests showed raised levels of C-reactive protein and lactate dehydrogenase. Bone marrow aspiration and biopsy were negative. [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) showed intense uptake within a right apical nodule and intense and diffuse uptake of FDG in the lungs without corresponding structural CT abnormality. Lung biopsy showed intravascular large B-cell lymphoma (IVLBCL). FDG-PET findings in IVLBCL and causes of diffuse FDG lung uptake with and without CT abnormalities are discussed.

Early encephalic toxicity after inadvertent intrathecal injection of low osmolar contrast medium.

Only nonionic contrast media are allowed for intrathecal use because of their lower neurotoxicity. In case of inadvertent intrathecal administration of an ionic contrast medium, the typical following syndrome is called ascending tonic clonic seizure syndrome. We describe the case of a 61-year-old woman with low back pain who underwent myelography. Ioxaglate, a water-soluble ionic low osmolar contrast medium was accidentally injected intrathecally. She first presented encephalic signs of neurotoxicity, followed by opisthotonic spasms and respiratory distress. In our case, ioxaglate is a low osmolar agent, leading to early encephalic toxicity (preceding medullary signs), because of its cephalic migration. The patient was successfully treated by sedation, anticonvulsant therapy and fluid hydration. Intrathecal administration of an ionic contrast medium is clearly contraindicated. In case of inadvertent injection of a low osmolar product, encephalic signs are seen first.

[Iatrogenic venous cerebral air embolism without pulmonary manifestation: A retrograde mechanism?]. / Embolie gazeuse cérébrale iatrogène d'origine veineuse sans signe respiratoire : un mécanisme rétrograde ?

INTRODUCTION: Air embolism is a rare complication of various invasive medical procedures. Venous cerebral air embolism is usually the consequence of paradoxical embolism. We report a case of isolated cerebral air embolism resulting from a non-paradoxical mechanism. CASE REPORT: A few minutes after his central venous catheter had been accidentally disconnected, a 63-year-old man developed left-sided rhythmic jerking movements followed by left hemiplegia. There were no associated cardiologic or pulmonary signs. Brain CT showed air bubbles in the right frontal cortical sulci. The brain MRI DWI and FLAIR sequences showed a high intensity right frontal cortical lesion without reduction in ADC. Transesophageal echocardiogram did not find a patent foramen ovale. CONCLUSIONS: In this case of venous cerebral air embolism, the lack of any cardiopulmonary manifestation, the lack of a patent foramen ovale and the neuroradiological findings are not in favor of the hypothesis of paradoxical embolism. The hypothesis of retrograde venous cerebral air embolism is discussed.

Osteoid osteoma invading the posterior labyrinth of the petrous bone.

We report a painless osteoid osteoma of the inner ear in an elderly woman presenting with hearing loss, tinnitus, and vertigo. CT showed a heterogeneous mass containing calcifications involving the posterior labyrinth, which heterogeneously enhanced on postcontrast MR images. Osteoid osteoma should be included in the differential diagnosis of an osteolytic petrous bone lesion with central calcification and enhancement.