Accuracy of ultrasonography in the evaluation of abdominal masses in children in Nigeria

Introduction: Abdominal masses in children constitute a spectrum of lesions of diverse origin, nature and significance. In a low-income setting with limited investigative facilities, accurate diagnosis of abdominal masses can be very challenging. However, ultrasound has been used preferentially as a diagnostic tool in evaluating abdominal masses in children. This study aimed to determine the accuracy of ultrasound evaluation of abdominal masses in children. Materials and Methods: This was a prospective descriptive study of 135 consecutive children presenting with palpable and/or suspected abdominal masses over a 1-year period at a tertiary hospital. Data analyses were done using SPSS version 17 software and level of significance was set at P < 0.05. Results: Abdominal mass was located in the kidney in 40 (32.3%) patients. Definitive diagnoses of abdominal masses were confirmed intraoperatively in 33 (24.4%) and by histopathological examination in 102 (75.6%) cases. Abdominal masses were detected in 124/135 (91.9%) of the participants. Ultrasound (US) correctly identified 109/124 (87.9%) of the pathologies. The sensitivity and specificity of USS were 87.9% and 81.8%, respectively. Positive predictive value (PPV) and negative predictive value (NPV) were 97.2%–98.2% and 37.5%–45.7%, respectively. The overall US diagnostic accuracy was 87.4%. The predictive value of US for intussusceptions, Wilms' tumour and hydronephrosis was high (sensitivity was 92.0%, 95.8% and 81.1% and PPV was 90.0%, 83.0% and 93.8%, respectively). On the other hand, the sensitivity indices for appendiceal mass/abscess, lymphoma and neuroblastoma were low (28.6%, 66.7% and 57.1%, respectively), while their PPV was low too (66.7%, 42.9% and 77.7%, respectively). The PPV was especially poor for lymphoma. The specificity and NPV indices for these six disease conditions were good. Conclusion: Ultrasound is a reliable tool in the evaluation of abdominal masses in children in this setting.