1Department of Clinical Laboratory, Kawasaki Medical School Hospital, 2Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, 3Department of Internal Medicine, Kawasaki Medical School
Juvenile polyp is a common cause of hematochezia in children. Although the initial and definite diagnoses of this disease are usually based on results of endoscopic or barium studies, the invasiveness of these examinations remains a problem in their use in a primary examination. We discuss a case of juvenile polyp in which transabdominal ultrasonography was useful in detecting and diagnosing a polyp located in the descending colon. A boy aged 2 years had a 1-year history of chance hematochezia. Transabdominal ultrasound revealed a polypoid lesion containing multiple cystic areas. Color Doppler disclosed blood vessels distributed like tree branches. The symptom ceased after endoscopic polypectomy was carried out. Comparing images obtained by water-immersion ultrasonography with the histopathology of the resected specimen revealed that the cystic areas represented dilated epithelial tubules, a characteristic feature of juvenile polyp.