Limited Value In Differential Diagnosis Research Articles

Sonoelastography for differential diagnosis between malignant and benign parotid lesions: a meta-analysis

ObjectivesTo assess the performance of sonoelastography for differential diagnosis between malignant and benign parotid lesions using a meta-analysis.MethodsAn independent literature search of English medical databases, such as PubMed, Embase and Medline (Embase.com), Web of Science, Cochrane Library and Ovid was performed. The diagnostic accuracy of sonoelastography was compared with that of histopathology and/or cytology, which was used as reference standard. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC) were calculated to evaluate the accuracy of sonoelastography. A meta-regression analysis evaluating imaging mechanisms, shear wave elastography techniques, assessment methods and QUADAS scores was performed.ResultsTen eligible studies that included a total sample of 711 patients with 725 parotid lesions were included. Sonoelastography showed a pooled sensitivity of 0.67 (95% CI 0.59–0.74), specificity of 0.64 (95% CI 0.60–0.68), DOR of 8.00 (95% CI 2.96–21.63) and an AUC of 0.77. The results of the meta-regression analysis revealed that no heterogeneity was due to the imaging mechanism (p = 0.119), shear wave elastography technique (p = 0.473) or QUADAS score (p = 0.462). However, the assessment method was a significant factor that affected the study heterogeneity (p = 0.035). According to the subgroup analysis, quantitative and semiquantitative methods performed better than qualitative ones.ConclusionOverall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions. Quantitative and semiquantitative methods perform better than qualitative ones.Key Points• Overall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions.• Quantitative and semiquantitative assessment methods perform better than qualitative ones.• Semiquantitative and quantitative methods are automatically calculated by an ultrasound machine and are thus less operator-dependent.

Improving adrenal venous sampling in primary aldosteronism

Primary aldosteronism is the most frequent cause of secondary arterial hypertension. As adrenal imaging has been shown to have only limited value for differential diagnosis, adrenal vein sampling (AVS) has been implemented as a gold standard in the guidelines. However, AVS is a not well-standardized technique, and success rates vary in a wide range. Successful AVS procedures presuppose careful preparation and operational efficiency in an interdisciplinary team. Besides ruling out malignancy, multidetector-row helical computed tomography facilitates the localization of the adrenal veins. Rapid cortisol measurement has been shown to increase cannulation rates. The values of cosyntropin stimulation and bilateral simultaneous versus sequential catheterization remain unclear, but consistency is important. AVS should be performed in specialized centers by a limited number of radiologists in order to ensure success rates of at least 70%. Standardization of cutoff values should be accomplished through a consensus statement for consistent decision-making in patient care.

Causes of and diagnostic approach to methylmalonic acidurias

Several mutant genetic classes that cause isolated methylmalonic acidurias (MMAuria) are known based on biochemical, enzymatic and genetic complementation analysis. The mut(0) and mut(-) defects result from deficiency of MMCoA mutase apoenzyme which requires adenosyl-cobalamin (Ado-Cbl) as coenzyme. The cblA, cblB and the variant 2 form of cblD complementation groups are linked to processes unique to Ado-Cbl synthesis. The cblC, cblD and cblF complementation groups are associated with defective methyl-cobalamin synthesis as well. Mutations in the genes associated with most of these defects have been described. Recently a few patients have been described with mild MMAuria associated with mutations of the MMCoA epimerase gene or with neurological symptoms due to SUCL mutations. A comprehensive diagnostic approach involves investigations at the level of metabolites, genetic complementation analysis and enzymatic studies, and finally mutation analysis. MMA levels in urine range from 10-20 mmol/mol creatinine in mild disturbances of MMA metabolism to over 20000 mmol/mol creatinine in severe MMCoA mutase deficiency, but show considerable overlap and are of limited value for differential diagnosis. The underlying defect in isolated MMAuria can be characterized in cultured skin fibroblasts using several assays, e.g. conversion of propionate to succinate, specific activity of MMCoA, cobalamin adenosyltransferase assay, cellular uptake of CN-[(57)Co] cobalamin and its conversion to cobalamin coenzymes and complementation analysis. The reliable characterization of patients with isolated MMAuria pinpoints the correct gene for mutation analysis. Reliable classification of these patients is essential for ongoing and future prospective studies on treatment and outcome.

Expression of proliferating cell nuclear antigen in follicular thyroid tumors: correlation with clinicopathological findings.

The purpose of this study was to correlate proliferating cell nuclear antigen (PCNA) immunostaining with clinicopathological findings in 60 follicular thyroid tumors. Mean proliferative index (PI) was significantly higher for carcinoma (73%) than microfollicular adenoma (19.6%) (p<0.0001). For atypical and oncocytic adenomas, intermediate PI values (64% and 50%) correlated with size and cytological atypia but not with sex and age. PCNA immunostaining is of limited value for differential diagnosis of malignant and atypical tumors but could be useful for identification of actively growing atypical follicular thyroid nodules on fine needle aspiration biopsies.

Relative quantification of signal on T2-weighted images in the basal ganglia: limited value in differential diagnosis of patients with parkinsonism.

A reduction in signal in the basal ganglia on T2-weighted images is said to correlate with a poor response to L-DOPA and may help to identify patients with non-idiopathic parkinsonism. Our aim in this prospective study was to use the contrast-to-noise ratio of the MRI signal on T2-weighted images in various parts of the basal ganglia in 43 patients with de novo parkinsonism. Signal intensity measurements were compared to the response to the dopamine agonist apomorphine and dopamine-D2 receptor binding obtained by 3-iodo-6-methoxybenzamine single-photon emission computed tomography (IBZM-SPECT). A reduced contrast-to-noise ratio in the putamen correlated significantly with a negative response to apomorphine and reduced striatal IBZM binding. No additional signal intensity measurement correlated with response to apomorphine or specific IBZM binding. However, there was a considerable overlap of contrast-to-noise ratios between patients with a positive or negative response to apomorphine or normal and reduced IBZM binding. We suggest that semiquantitative assessment of signal intensity in the putamen shows a significant reduction in patients with probably nonidiopathic parkinsonism compared with patients with probably idiopathic parkinsonism. However, this method does not exclude idiopathic parkinsonism in a given patient.

HIGH PREVALENCE OF UNRECOGNIZED OSTEOMALACIA IN HOSPITAL PATIENTS WITH RHEUMATOID ARTHRITIS

A consecutive series of 31 patients with rheumatoid arthritis (RA) admitted over a 6-month period to the rheumatology unit of a District General Hospital were screened for possible osteomalacia. Transiliac bone biopsies were performed in 14 patients where the above diagnosis was suspected, yielding four (12.9%) cases of osteomalacia. All affected patients were elderly women who had a poor diet and were virtually housebound. Additional risk factors in two cases were partial gastrectomy and occult coeliac disease. Biochemical screening was of limited value in differential diagnosis, since elevated serum alkaline phosphatase levels were noted in both osteomalacic and non-osteomalacic patients. This study indicates that, in the West of Scotland at least, osteomalacia is a common, easily overlooked and treatable cause of morbidity in elderly patients with RA.

Pulmonary Manifestations of the Clinical Syndrome of Acute Glomerulonephritis and Lung Hemorrhage

The pulmonary manifestations at the time of initial diagnosis were reviewed in 45 patients with the clinical syndrome of acute glomerulonephritis and lung hemorrhage. Initial pulmonary radiographic appearances encompassed a wide variety of abnormalities, and alveolar hemorrhage could not be reliably differentiated from other causes of pulmonary infiltration. The diseases underlying the syndrome included antiglomerular basement membrane (anti-GBM) disease (8/45), a systemic vasculitis (25/45), and idiopathic glomerulonephritis with idiopathic lung hemorrhage (12/45). A variety of acute pulmonary complications were seen, the most common being acute respiratory failure (13/45). Mortality directly due to pulmonary disease was uncommon (3/45 died from fulminant lung hemorrhage). Most deaths were from extrapulmonary manifestations of the underlying disease or infection. Follow-up studies in 22 patients 6 months after initial presentation indicated that although respiratory symptoms (3/22) or pulmonary radiologic abnormalities (5/22) were uncommon, the majority of patients had residual abnormalities on pulmonary function testing (16/22). Thus, the syndrome of alveolar hemorrhage with nephritis is associated with several distinct categories of underlying disease process. The initial chest radiograph is of limited value in differential diagnosis. Although a variety of acute and chronic respiratory complications may be anticipated and contribute significantly to morbidity, mortality is predominantly due to extrapulmonary progression of disease or infection complicating immunosuppressive therapy.

Intravenous cholegraphy and diaphragmatic movements in the differential diagnosis of acute cholecystitis (author's transl)

Intravenous cholegraphy was performed in 79 patients with abdominal symptoms suggestive of acute cholecystitis. Three excretion patterns were found: 1. Opacification of the gall bladder and common bile duct. 2. Opacification of the common bile duct. 3. No opacification of the gall bladder or common bile duct. 29% showed opacification of the gall bladder and common bile duct; none of these had acute cholecystitis. 51% of cases showed opacification of the common bile duct only; 82.5% of these had acute cholecystitis. 79.4% of patients with this excretion pattern were shown to have acute cholecystitis at operation. In the other cases, absence of opacification of the gall bladder was due to obstruction of the cystic duct, caused either by concretions or fibrosis. The biliary tree was not visible in 21% of cases. The most common diagnosis was acute cholecystitis, but this excretion pattern is of limited value in differential diagnosis. The value of this examination is stressed, but it must be carried on for an adequate period. Mobility of the right diaphragm was examined preoperatively in 34 patients. Compared with patients with other diagnoses, there was a significant number of patients with acute cholecystitis who showed limited movement. The examination may be regarded as supplementary to intravenous cholegraphy in the diagnosis of acute cholecystitis.