Sonographic “speech bubble/speech box sign” in clinically occult femoral hernias: ultrasound findings and anatomical basis

Femoral hernia is the protrusion of a peritoneal sac through the femoral ring into the femoral canal lying deep and inferior to the inguinal ligament. The hernia sac usually contains preperitoneal fat, omentum, bowel, or fluid. Ultrasound is recommended as the first-line investigation for diagnosing clinically occult femoral hernias in nonemergency settings, whereas CT is the imaging of choice in emergency settings. High accuracy of the ultrasound in clinically occult femoral hernia is further validated with further CT and MRI. In this article, we propose sonographic detection of the physiological peritoneal fluid herniating through capacious femoral ring manifesting as a "speech bubble/speech box appearance." This is a potentially invaluable sonographic sign for clinically occult femoral hernias, differentiating them from inguinal hernias and cysts of the canal of Nuck in females and preventing inadvertent attempts to aspirate.