A 9.3-month-old female was admitted to the Department of Pediatrics, the First Affiliated Hospital, Jinan University with the complaint of jaundiced skin over 9 months. The patient presented with sustained jaundice since 7 days after birth, but it was until her age 8.5 months that she was firstly referred to a local hospital where biochemistry test revealed raised serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL). Then she was admitted to our hospital at the age 9.3 months, when physical examination revealed jaundiced skin and sclera, enlarged liver 6.5 cm below the right costal margin, and enlarged spleen 6 cm below the left costal margin. Moreover, markedly raised serum alpha-fetoprotein (AFP) was detected besides elevated ALT, AST, TBIL, DBIL, and IBIL (Table 1), indicating a cholestatic liver disease. On SLC25A13 analysis at her age 10 months, the patient proved to be homozygous for the prevalent pathogenic mutation c.852_855del4, and thus NICCD was definitely diagnosed. Thereafter, a lactose-free and medium-chain triglycerides (MCT)-enriched formula was administered. She was discharged a month later, and her jaundice and hepatosplenomegaly resolved gradually on subsequent follow up in our clinic, and the liver function indices returned to normal at the age 1 years and 9 months (Table 1).

However, when aged 4 years and 9 months, she was referred to the hospital once again with the complaint of abdominal distention for 2 weeks. Physical examination at referral revealed a body temperature of 36.6 ℃, heart rate 102 beats/min (bpm), respiratory rate 21 bpm, weight 16.2 kg, height 102.7 cm, and head circumference 48.1 cm. No jaundice was observed in the skin and sclera. Respiratory and cardiac examination was unremarkable. A liver 7.0 cm below the right and a spleen 4.0 cm below the left costal margin, were palpable both in the mid clavicular line. Neurological exam was normal. The extremities were warm, and the distal perfusion was excellent. Laboratory tests showed a markedly elevated serum AFP level of 27,605 ng/ml (reference range:0–12 ng/mL), and ALT, AST, γ-glutamyl transpeptidase (GGT) and total bile acids (TBA) levels were also raised (Table 1). Abdominal ultrasonography revealed multiple strong echoes in the liver, with the largest one being 28 × 30 mm in size. Magnetic resonance imaging (MRI) showed a large mass of 82 × 95 × 78 mm in size in the right hepatic lobe and an embolus in the portal vein. Further enhanced computed tomography (CT) revealed multiple masses in the right hepatic lobe with the largest one 97 × 85 × 89 mm in size; a suspected tumor embolus within the portal vein and an enlarged spleen were also observed (Fig. 1).

Abdominal enhanced CT findings of the patient at the age 4 years and 9 months. Coronal and axial contrast-enhanced CT images in arterial phase (A) demonstrated a large mass in the right lobe of the liver with the heterogeneous arterial enhancement (yellow arrow) and the enlarged spleen (blue arrow), while portal-venous phase (B) showed a large mass in the right lobe of the liver with wash out (yellow arrow) and a tumor thrombus within the portal vein (red arrow)

Her serum AFP level increased rapidly to 134392 ng/ml at the age 4 years and 10 months, when a pre-operative biopsy was conducted on the hepatic mass, and hepatoblastoma was suspected on pathological analysis. The tumor was staged to PRETEXT IV, and the patient underwent neoadjuvant chemotherapy consisting of one course of cisplatin (DDP), two courses of DDP + pirarubicin (THP), and one course of ifosfamide + carboplatin + VP-16(ICE). During the chemotherapy, she experienced recurring anemia, agranulocytosis and thrombocytopenia and was treated symptomatically. As a result, the mass was decreased in size, reaching partial response (PR) on CT-scan under RECIST criteria, and the serum AFP level declined to 25530 ng/ml. This provided an opportunity for surgical resection, and liver transplantation was not immediately considered. Hence, at the age 5 years and 3 months, the patient underwent right hepatic lobectomy and portal venous embolectomy in the Department of Pediatric Surgery, the First Affiliated Hospital, Sun Yat-Sen University. Multiple gray-white solid nodules were observed on a longitudinal section of the resected right hepatic lobe (Fig. 2). Subsequent histopathological analysis of the resected liver and embolus tissues confirmed a fetal epithelial subtype of H, with membrane-staining pattern of Beta-catenin, Cytokeratin 19 and Hepatocyte, along with cytoplasmically positive AFP and Glypican 3, as well as partially nucleus-staining Tumor protein 53(TP53) (Fig. 3). Thereafter, she underwent 5 additional cycles of chemotherapy of ICE regimen, exhibiting a stable postoperative condition for 7 months. Her serum AFP further descended to the level of 5219 ng/ml after surgery and to the lowest 480 ng/ml during the postoperative chemotherapy. However, at the age 5 years and 10 months, her AFP rebounded to 63866 ng/ml, and abdominal ultrasonography revealed “multiple echogenic lesions” in the left liver with the largest one 9 × 7 mm in size, indicating recurred hepatoblastoma. Then her condition deteriorated rapidly into liver failure, and finally led to death at the age 6 years and 1 month.

Longitudinal section of the resected right liver lobe. Note the multiple gray-white solid nodules with 0.3–1.2 cm of diameters in size, which displayed well circumscribed or partially encapsulated

Histopathological findings of the resected liver tissue from the patient with citrin deficiency. Microscopically, multiple nodules were observed in the inflammatory and cirrhotic liver context (A, B), and the nodules were composed of angulated epithelial-like cells, resembling early-stage differentiation of hepatocytes (C). The neoplastic cells arranged in irregular cords and display abundant eosinophilic cytoplasm with indistinct or angulated cellular borders; Nucleus was large or clear with a small nucleolus and less mitoses (D). Immunohistochemical staining showed membrane-staining pattern of Cytokeratin 19 (E), Hepatocyte (F) and Beta-catenin (G), along with partially nucleus-staining TP53 (H). AFP and Glypican 3 were both positive in a cytoplasmic pattern (not shown)