An Unusual Case With a Huge Hepatic Cystic Mass

Question: A 5-year-old Taiwanese girl was admitted to our hospital because of periumbilical abdominal pain for 2 weeks and fever. She had stayed in Guangdong, China, for 2 months. At admission, the liver could be palpated 2 cm below the right costal margin. Her white cell count was 6960/μL (segmented, 89.9%; eosinophils, 2.2%), platelet count was 76,000/μL, and C-reactive protein level was 7.23 mg/dL. Notable laboratory values included aspartate aminotransferase, 140 U/L; alanine aminotransferase, 124 U/L; γ-glutamyl transferase, 63 U/L; and a prolonged prothrombin time, with an international normalized ratio of 1.68. Serum levels of bilirubin, β-human chorionic gonadotropin, α-fetoprotein, vanillylmandelic acid, and indirect hemagglutination antibody for amoeba were within normal limits. Abdominal ultrasonography revealed a heterogeneous tumor (7.4 × 6.5 cm diameter) in the right lobe of the liver, with invasion of the inferior vena cava (IVC) (Figure A). Computed tomography (CT) and magnetic resonance imaging (MRI) showed one cystic lesion with wall enhancement at the S6/7 segments with filling defects in the right hepatic vein and IVC (Figure B). The eosinophil percentage increased to 9.7% during the first week of hospitalization. The patient complained of intermittent diplopia after admission. Brain MRI disclosed 1 lesion (1.6 × 1.6 × 1.3 cm) at the superior cerebellar hemisphere (Figure C). Based on suspicion of hydatid cyst with brain dissemination, albendazole (15 mg · kg−1 · d−1, twice daily) was added to the treatment regimen. Leukopenia developed 2 weeks after taking albendazole, with a nadir white cell count of 1530/μL. Because of concern over adverse drug reactions, praziquantel was used instead. Echocardiography-guided percutaneous puncture, aspiration, injection, and respiration with 3% normal saline injection was performed 5 weeks after admission due to the poor regression of the lesion. A total of 17 mL of straw-colored fluid was drained. Microscopically, there were no pus cells, malignant cells, visible pathogens, or hydatid sand. Follow-up abdominal CT revealed a shrinking liver mass (3.2 cm in diameter) and no thrombosis in the IVC. Atypical hepatectomy (partial S5/S6) and partial IVC resection were performed 3 months after the onset of clinical symptoms. What is your diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. A thick-walled cyst with yolk-colored debris was removed (Figure D). Pathologic analysis confirmed the lesion to be a degenerated cyst of racemose cysticercus. The wall of the cysticercus was necrotic and composed of tegument and a narrow wall of stroma (Figure E). No parts of a protoscolex were evident. After the operation, the patient recovered, and there was no evidence of recurrence during a 3-year follow-up. The initial presentation of the huge liver cyst with septum formation led to suspicion of echinococcal infection. Hydatid cyst is more likely to be found in the liver. The involvement of IVC and thrombosis rendered the hepatic lesion initially unresectable. Although antihelminth therapy and a percutaneous puncture, aspiration, injection, and respiration procedure did not eradicate the lesion, they decreased its size and cleared the IVC lesions, enabling further operations. In the lifecycle of Taenia solium, pigs are intermediate hosts and humans are definite hosts. After being infected by eating eggs or gravid proglottids, humans become intermediate hosts. Oncospheres may invade the intestinal wall and disseminate hematogenously to the liver, brain, muscle, and soft tissue with development of cysticerci in 3 to 8 weeks. Liver involvement is a rare condition in cysticercosis1Chaudhary V. Bano S. Kumar P. et al.Hepatic cysticercosis: a rare entity.Abdom Imaging. 2014; 39: 1182-1185Google Scholar compared with neurocysticercosis, which is the most common type of systemic Taenia infection. Racemose cysticercus is a special entity of cysticercosis. It presents as multiple budding bladders forming an irregular mass in a racemose pattern, typically without a protoscolex. The cause of racemose cysticercus is unknown. This type of Taenia infection typically occurs in the central nervous system, especially the ventricles. There is but 1 case report with abdominal-wall involvement in the literature.2Cho S.Y. Cho B.K. Choi W.Y. An acephalic budding cysticercus (= racemose cysticercus) found at the abdominal wall of a man.Kisaengchunghak Chapchi. 1985; 23: 260-268Google Scholar Our patient is the first documented racemose cysticercus in the liver, only 8 cases of which have been reported.1Chaudhary V. Bano S. Kumar P. et al.Hepatic cysticercosis: a rare entity.Abdom Imaging. 2014; 39: 1182-1185Google Scholar,3Sen K. Karmakar P. Bandyopadhyay A. et al.Cysticercosis involving muscles and liver only: a yet unknown entity.Ann Trop Med Public Health. 2013; 6: 350-352Google Scholar