Giant simple biliary cyst in a 2-year-old child: a case report

Simple biliary cysts are exceptionally rare in pediatric patients and seldom manifest as giant hepatic masses. Their clinical and radiological overlap with malignant tumors poses diagnostic challenges, potentially leading to unnecessary aggressive interventions. A 2-year-old female presented with progressive abdominal distension and recurrent pneumonias. Physical examination revealed a protuberant abdomen with visible venous collaterals. Liver span was 18 cm by percussion, with no splenomegaly. Laboratory findings included a hemoglobin level of 10.8 g/dL. Tumor markers (AFP and β-hCG) were within normal limits. X-ray studies demonstrated bilateral elevated hemidiaphragm and right basal consolidation. Abdominal ultrasound found a large anechoic lesion (18 × 15 × 12 cm) with internal septations and posterior acoustic enhancement, replacing the right hepatic lobe, with no Doppler flow, and compression of the inferior vena cava. Contrast-enhanced computerized tomography (CT) revealed a hypodense mass with peripheral rim enhancement and absence of centripetal filling, alongside right renal displacement, gastric compression, and diaphragmatic elevation. The patient was taken to the operating room for an exploratory laparotomy. Through a supraumbilical transverse incision extended on the midline below the umbilicus, the mass was entirely delivered. Anatomical resection of segments IV A and B was performed, including the mass, which weighted 6.5 kg. The postoperative course was uneventful apart from a self-limiting biliary leak managed conservatively. Histopathological analysis confirmed a simple biliary cyst with no evidence of malignancy. The patient had a complete resolution of respiratory symptoms and showed no recurrence at six months of follow-up. Simple biliary cysts, although rare, must be considered in the differential diagnosis of giant hepatic cystic masses in children. Complete surgical excision is the treatment of choice.