The role of ultrasonography in differential diagnosis of orbital lesions.

AIMS: The aim of this study is to assess the value of ultrasound in the differential diagnosis of orbital lesions. METHODS: One hundred and thirty-eight patients with clinical features of an orbital mass were examined by orbital ultrasound prior to undergoing surgery, from January 2000 to January 2017. All patients underwent excisional or incisional orbital biopsy. The results of orbital ultrasonography were compared with the final histological diagnosis. RESULTS: Orbital lesions were localized by ultrasonography in 133/138 cases (96.4%); the false-negative rate of orbital echography was 3.6% (5/138). The nature of the orbital lesions was correctly determined by ultrasonography in 54.3% of the cases (75/138) preoperatively (true positives). In 58/138 (42%) patients, there was no correspondence between the ultrasound diagnosis and the histological diagnosis (false positives). The sensitivity of orbital ultrasonography for the detection of an orbital mass was 93.75% (CI 87.87-99.63%), while the specificity yielded no meaningful result (CI 0.00-60.24%). Moreover, the specificity of orbital ultrasonography to identify a malignant tumor falls within a CI of 0-62.72%. CONCLUSIONS: Orbital ultrasonography is a rapid and noninvasive test that is highly sensitive in displaying an orbital mass; however, the specificity in the differential diagnosis of orbital lesions is not meaningful, particularly if malignancy is suspected. The assessment of orbital diseases requires multiple diagnostic approaches to balance the strengths and weaknesses of each method.