Thyrotoxicosis factitia masquerading as recurrent Graves' disease: endogenous antibody immunoassay interference, a pitfall for the unwary.

Antibody interference in immunoassays is an underestimated problem, which has the potential to cause patient harm and waste health-care resources. We report a case where thyroglobulin antibodies generated a false-positive thyroglobulin result delaying the diagnosis of thyrotoxicosis factitia masquerading as recurrent Graves' disease. A high index of clinical suspicion and good laboratory-clinician communication underpins effective clinical and laboratory strategies to detect potentially erroneous laboratory results due to endogenous antibody interference in immunoassays.

The MR imaging appearances and natural history of seromas following excision of soft tissue tumours.

Fluid collections (seromas) may accumulate at the site of surgery following excision of musculoskeletal soft tissue tumours. The aim of this retrospective study was to review the magnetic resonance (MR) imaging features of postoperative seromas identifying changes over time on follow-up scans. A total of 170 MR scans from 80 patients were reviewed showing one or more seromas. All patients had undergone previous surgery for a musculoskeletal soft tissue tumour. The typical MR appearances of a seroma were shown to be a well-defined oval or rounded (54%) soft tissue mass, arising at the site of previous surgery, with a thin, dark pseudocapsule, surrounding soft tissue oedema (80%), homogeneous contents that are hypointense (relative to adjacent muscle) on T1-weighted images (74%) and hyperintense on T2-weighted and STIR images (79%). Approximately one-quarter of cases revealed atypical features including hyperintense contents on T1-weighted (26%) and/or heterogeneous contents on T2-weighted images (21%), reflecting the breakdown of blood products and organization of the fluid collection. A distinctive fine feathery pattern arising from the inner surface of the seroma or from septations was identified in 10% of cases. In those patients who underwent one or more follow-up scans, the volume of the seromas decreased in 66% cases, remained unchanged in 15% and increased in 19%. Seromas are not an uncommon finding (<10% of cases) following surgery for a soft tissue tumour. The majority of cases show the typical MR features of a fluid collection. The pitfalls in differentiating an atypical seroma from a recurrent soft tissue sarcoma are discussed.

Significance of reverse transcription polymerase chain reaction in the detection of human cytomegalovirus gene transcripts in thoracic organ transplant recipients.

BACKGROUND: Cytomegalovirus disease is a major cause of morbidity in transplant recipients. We have evaluated the clinical value of detecting viral mRNA transcripts for the diagnosis of active infection leading to disease in recipients of thoracic organ transplants. METHODS: Blood samples from 10 transplant recipients were analyzed before transplantation and weekly after transplantation for 12 weeks. The profile of viral immediate-early, early, and late gene expression was determined by the reverse transcription polymerase chain reaction and compared with cytomegalovirus (pp65) antigenemia and host antibody status (serologic study). RESULTS: Two patients showed no active cytomegalovirus infection, one had asymptomatic infection detected serologically and seven patients had development of symptomatic infection with a significant serologic change. Viral immediate-early mRNA transcript was detectable in all 10 patients, including the two with no active infection. Early and late gene expression occurred in seven patients who were all antigenemia positive and in whom disease developed. Of the seven patients with development of antigenemia, six showed viral early and late gene expression before pp65 antigenemia, whereas one patient showed antigenemia before early and late gene expression. CONCLUSION: We have shown that the detection of viral early and late gene expression by reverse transcription polymerase chain reaction can act as diagnostic markers of cytomegalovirus disease with expression of early gene preceding the detection of antigenemia in most cases. In contrast, viral immediate early gene expression did not correlate with clinical infection. This diagnostic approach could be useful in the treatment of thoracic organ transplant recipients.