The minimum volume of pleural fluid required to diagnose malignant pleural effusion: A retrospective study.

BACKGROUND: Pleural fluid cytology is a quick and accurate method to diagnose malignant pleural effusions. The optimal volume of fluid for cytological analysis has not yet been identified, and clinical recommendation based on some published clinical experiences has been to send large volumes of fluid for cytological analysis. A quality improvement initiative at our institution was conducted to determine the volume of fluid sufficient for a diagnosis of malignant pleural effusion. MATERIALS AND METHODS: The study was approved by the Institutional Review Board. All pleural fluid specimens that were divided into three volumes (25 mL, 50 mL, and 150 mL) and sent for cytological examination were reviewed. RESULTS: A total of 74 samples from 60 individual patients were evaluable. Thirty-six patients (60%) had a previous diagnosis of malignancy. Of the 74 specimens, 26 (35.1%) were positive for malignancy. The detection rate for malignant pleural effusion by cytology for 25 mL, 50 mL, and 150 mL were 88.5%, 96.2%, and 100.0%, respectively (P = 0.16). Two specimens that were negative in the 25 mL samples turned out to be positive in the 50 mL and 150 mL samples. One specimen was negative in the 25 mL and 50 mL samples but positive in the 150 mL sample. CONCLUSIONS: Our study did not show any statistically significant difference in the detection of malignant effusion in the 25 mL, 50 mL, and 150 mL group.

Raccoon rabies virus variant transmission through solid organ transplantation.

IMPORTANCE: The rabies virus causes a fatal encephalitis and can be transmitted through tissue or organ transplantation. In February 2013, a kidney recipient with no reported exposures to potentially rabid animals died from rabies 18 months after transplantation. OBJECTIVES: To investigate whether organ transplantation was the source of rabies virus exposure in the kidney recipient, and to evaluate for and prevent rabies in other transplant recipients from the same donor. DESIGN: Organ donor and all transplant recipient medical records were reviewed. Laboratory tests to detect rabies virus-specific binding antibodies, rabies virus neutralizing antibodies, and rabies virus antigens were conducted on available specimens, including serum, cerebrospinal fluid, and tissues from the donor and the recipients. Viral ribonucleic acid was extracted from tissues and amplified for nucleoprotein gene sequencing for phylogenetic comparisons. MAIN OUTCOMES AND MEASURES: Determination of whether the donor died from undiagnosed rabies and whether other organ recipients developed rabies. RESULTS: In retrospect, the donor's clinical presentation (which began with vomiting and upper extremity paresthesias and progressed to fever, seizures, dysphagia, autonomic dysfunction, and brain death) was consistent with rabies. Rabies virus antigen was detected in archived autopsy brain tissue collected from the donor. The rabies viruses infecting the donor and the deceased kidney recipient were consistent with the raccoon rabies virus variant and were more than 99.9% identical across the entire N gene (1349/1350 nucleotides), thus confirming organ transplantation as the route of transmission. The 3 other organ recipients remained asymptomatic, with rabies virus neutralizing antibodies detected in their serum after completion of postexposure prophylaxis (range, 0.3-40.8 IU/mL). CONCLUSIONS AND RELEVANCE: Unlike the 2 previous clusters of rabies virus transmission through solid organ transplantation, there was a long incubation period in the recipient who developed rabies, and survival of 3 other recipients without pretransplant rabies vaccination. Rabies should be considered in patients with acute progressive encephalitis of unexplained etiology, especially for potential organ donors. A standard evaluation of potential donors who meet screening criteria for infectious encephalitis should be considered, and risks and benefits for recipients of organs from these donors should be evaluated.

Radiological evaluation of interstitial lung disease.

PURPOSE OF REVIEW: Chest radiograph, computed tomography and high-resolution computed tomography (HRCT) are an integral part in the diagnosis and evaluation of diffuse interstitial lung disease (DILD) and are reviewed briefly. This review then delves into the burgeoning interest associated with enhanced imaging and computational capabilities of multidetector HRCT in the automated evaluation of computer-aided recognition of different patterns associated with DILD, automated regional and global distribution and quantitation of DILD, and automated longitudinal comparison of HRCT scans to estimate progression of DILD. RECENT FINDINGS: Problems associated with automatic segmentation of lung in DILD because of high-attenuation lesions in subpleural locations have been overcome to a large extent. Use of two-dimensional HRCT has made it possible to automate identification and quantification of patterns associated with DILD with an overall accuracy of 89%. Significant progress has been made with automated image registration and noise reduction, which are essential for sequential comparison of HRCT in DILD. Early experience with automated determination of progression or regression of DILD on two-dimensional HRCT, using the dissimilarity-based feature strategy, compared favorably with radiologist assessment and approached a concordance rate of 80%. SUMMARY: The combination of multidetector HRCT, the support vector machine classifier and various computational algorithms have made it possible to fully automate isolation of lungs in DILD, recognize radiographic patterns associated with DILD and sequentially estimate progression of DILD. It is hoped there will be further improvement when these are extended to three-dimensional HRCT.