Icterus and abdominal pain: an unexpected, rare sonographic finding in a Peruvian Emergency Department.

Background: The use of point-of-care ultrasound (POCUS) has become increasingly important in resource-limited settings. It can rapidly diagnose both tropical infectious diseases and more common pathology at the bedside. In these practice settings, POCUS can have a significant impact on management strategies and patient care. Ultrasonography has been the gold standard for the diagnosis and staging of Echinococcus disease. However, even in the "classic" clinical scenario and setting, the clinician must maintain a broad differential diagnosis. Point-of-care ultrasound can be helpful in performing the rapid diagnosis and therefore direct appropriate treatment strategies based on the results.

Case presentation: We present a case of a 27-year-old woman presenting to an emergency department in Peru with jaundice and abdominal pain. Initially given the region of her origin, the working diagnosis was an Echinococcus cyst. However, when POCUS was performed, the findings were not consistent with hydatid disease. Ultimately, surgical pathology revealed a choledochal cyst, a rare finding in adulthood.

Conclusions: This case initially appears as a "classic" finding of Echinococcus disease. It is important for the clinician sonographer to appreciate the features consistent with Echinococcus cysts and distinguish from those features that are more consistent with other pathology.