Intravascular lymphoma as an unusual cause of multifocal cerebral infarctions discovered on FDG-PET/CT.

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive variant of diffuse large B-cell lymphoma with frequent involvement of the central nervous system. Its atypical presentation often delays the diagnosis and due to its aggressive behaviour, the diagnosis is made post-mortem in half of the cases. We report a case of a 67-year-old male patient presenting with speech difficulties and balance disturbances in whom a magnetic resonance imaging (MRI) scan showed multiple lesions of the white matter, denoted as embolic infarctions. He was treated for a suspected endocarditis with antibiotics, but deteriorated neurologically with persistent fever. A consecutive FDG -PET /CT revealed an increased uptake in the adrenals, of which a biopsy showed IVLB CL. The patient was successfully treated with systemic R-CHOP with intrathecal methotrexate and achieved complete remission after six cycles of chemotherapy. The potential role of FDG-PET/CT is illustrated by this case leading to an exceptional diagnosis of IVLBCL.

Enzyme immunoassay for total oestrogens in pregnancy plasma or serum.

We have developed an enzyme immunoassay for total oestrogens in pregnancy serum of plasma, using horseradish peroxidase (HRP) as the marker enzyme. A test combination consisting of an antiserum against oestriol-16/17-monosuccinyl-albumin and oestriol-16/17-monosuccinyl-HRP yielded a sensitive system, which reacted to approximately the same extent with oestrone, oestradiol, oestriol and their 16- and 17-conjugates. Samples had to be diluted 1 to 10 to avoid interference of plasma factors with the immune reaction. Bound/free separation was achieved with the double antibody solid phase (DASP) method. The HRP activity of the bound fraction was measured, after washing, to eliminate plasma factors disturbing the HRP reaction. The detection limit of the assay system was approx. 0.1 pmol/tube, while the index of precision lambda ranged from 0.02 to 0.06. To measure total oestrogens, including the 3-conjugated ones, we used an enzymatic hydrolysis with an extract of Helix pomatia. Hydrolysis was found to be optimal after 1 h at 50 degrees C and pH 5.0. The method was used on serum samples from normal pregnancies. The results showed a very good correlation (r=0.98) with those obtained by radioimmunoassay. Normal values for total oestrogens during pregnancy were determined in a multicentre clinical trial.