Intrathoracic accessory liver tissue and cleidodysplasia in a newborn: a rare case report and literature review

Intrathoracic accessory liver tissue (IALT) is a rare congenital anomaly that can cause life-threatening respiratory compromise in neonates due to mass effect, yet its association with other skeletal dysplasias remains unexplored. We report the first known case of a neonate presenting with severe respiratory failure caused by a large IALT, concurrently diagnosed with congenital right-sided cleidodysplasia. Preoperative three-dimensional (3D) computed tomography (CT) reconstruction was pivotal in visualizing the vascular pedicle connecting the ectopic tissue to the main liver, effectively differentiating IALT from congenital diaphragmatic hernia (CDH), congenital pulmonary airway malformation (CPAM), multiple pulmonary sequestrations, and hepatic-pulmonary fusion. Importantly, we propose a novel volumetric ratio—comparing the IALT tissue volume to the right thoracic cavity capacity—to quantitatively assess its impact on respiratory function. Following stabilization with invasive mechanical ventilation, the patient underwent successful video-assisted thoracoscopic surgery (VATS), which required meticulous dissection of the feeding artery and draining vein while navigating the technical challenges of one-lung ventilation in a neonate. Postoperative histopathology confirmed Type II IALT. This case highlights the critical diagnostic value of 3D CT reconstruction in distinguishing IALT from other thoracic masses and demonstrates the feasibility of VATS for neonatal resection notwithstanding inherent technical complexities. The incidental co-occurrence of IALT and cleidodysplasia in this patient is noteworthy and merits further investigation. Furthermore, considering the theoretical risk of malignant transformation associated with other ectopic liver tissues, rigorous long-term follow-up is indicated. Finally, we reviewed and synthesized existing literature on pediatric IALT to elucidate its clinical characteristics and current diagnostic and therapeutic approaches.