46,52Several studies have indicated that a low long axis to short axis of lymph nodes (L/S ratio) is a significant sign of lymphoma and metastatic cancer.50,53-55 Steinkamp HJ et al.56 detected the L/S ratio less than 2 was indicative of metastatic lymph nodes with 95% accuracy. But there is not any cut-off value for distinguishing the exact cause. Therefore, the L/S ratio is one of the parameters in the evaluation of lymph nodes and as such should be considered with other findings to reach a diagnosis.51 Inhibitors,research,lifescience,medical Metastatic nodes are often hypoechoic50,51,57,58 in comparison to the adjacent tissues. The absence of hilum has been reported in 76-96% of malignant nodes.46,59,60The ultrasonographic characteristics of benign

and neoplastic LAPs Inhibitors,research,lifescience,medical are summarized in table 2.46,56,61 Table 2 Ultrasonographic Criteria of Benign and Neoplastic Lymphadenopathy The resistive index and the pulsatility index, vascular resistance indices measured by spectral Doppler ultrasound, are useful to distinguish malignant

from benign node disorders. Some studies have reported that malignancies Inhibitors,research,lifescience,medical in nodes tend to have a higher resistive index (>0.8) and pulsatility index (>1.5) than do reactive nodes.47,61,62However, other reports have posited that metastatic nodes have lower or similar vascular resistance compared with benign nodes.50,63 Stattic datasheet According to these various reports, the role of vascular resistance in the assessment of LAP is still controversial. Some studies have suggested Inhibitors,research,lifescience,medical using patterns of vascular distribution within the nodes to distinguish benign from malignant nodes.64-66 Normal nodes usually have hilar vascularity. Reactive nodes tend to have more prominent hilar vascularity due to an increase in the blood flow.61,67Metastatic lymph nodes often have a peripheral perfusion pattern and abnormal hilar structure.53,66,68 In ultrasound assessment, microcalcification may be detected in 50-69% of the cases of papillary thyroid carcinomas.53 Microcalcification

Inhibitors,research,lifescience,medical in metastatic axillary nodes is rare, but it strongly suggests breast cancer.46 Multiple lymph nodes, fusion tendency, and strong internal echoes (due to calcification) are the ultrasound characteristics of tubercular lymphadenitis.51,69 Tissue Diagnosis Tissue diagnosis is the gold standard in the evaluation of LAP. Fine needle aspiration cytology (FNAC) is a simple and safe Montelukast Sodium procedure and is proved to be accurate in the diagnosis of reactive hyperplasia, infections, granulomatous lymphadenopathies, lymphomas, and metastatic malignancies. It is most helpful when looking for the recurrence of a previously diagnosed cancer. It is easily performed in both inpatient and outpatient settings and yields results promptly.70 The accuracy of diagnosing metastatic carcinoma in lymph nodes by FNAC is 82-96%.71-73 Using ancillary techniques like immunohistochemistry and flow cytometry improves the accuracy of FNAC for the diagnosis of lymphomas.