BCS develops as a result of occlusion of the venous system at any location from the small veins to the junction of the inferior vena cava at the right atrium. This occlusion may be due to primary or secondary reasons. Primary reasons mostly include hypercoagulopathy disorders. Secondary reasons are a result of intraluminal invasion or extraluminal compression [3
]. In our case, secondary BCS developed due to both intraluminal invasion and extraluminal compression of the suprahepatic inferior vena cava and left hepatic vein. Patients with hepatic hydatid cyst, size and posterior localization of the cyst, invasion of 2 or more segments, and prior surgery or infection are the predisposing factors for development of BCS [4
]. In our case, most of the predisposing factors were present.
In a large scale survey conducted with 362 AE cases, BCS rates due to inferior vena cava invasion was reported to be approximately 1.8%. In another study, in BCS patients there were about 25% acute and 75% subacute clinical findings. The predominant symptom was found to be right upper quadrant abdominal pain [4
]. In our patient, the clinical findings had a subacute chronic course, and the predominant symptom was right upper quadrant abdominal pain.
Current treatments have substantially improved the prognosis of AE patients [6
]. However, early diagnosis is important for morbidity and mortality. AE generally remains asymptomatic for 5-10 years and later displays a chronic course. In cases that are not treated or insufficiently treated, mortality rates increase. After a diagnosis, a 5-year mortality rate of the disease is 70%, and a 10-year mortality is 94%. When BCS develops, 1-year mortality is 70%, and 3-year mortality is 90% [7
]. Our patient's life expectancy may be shortened due to the metastatic nature of the disease and the late initiation of treatment after surgery.
The treatment of BCS is medical and surgical. For chemotherapy, albendazole 10-15 mg/kg (in 2 divided doses) or alternatively mebendazole 40-50 mg/kg (in 3 divided doses) is used. Surgery is required for cases where BCS has developed. Other interventional methods (stent placing and angioplasty) or liver transplantation along with vena cava resection can be performed for BCS [7
]. Kawamura et al. [8
] have obtained good outcomes in advanced cases such as secondary BCS due to AE with chemotherapy followed by surgery. In a case report of the liver hudatid cyst with caval involvement, a combination of hepatic lobectomy and vena cava resection was reported to be successful. In disseminated abdominal hydatidoses, long-term chemotherapy reduces the incidence of recurrence and mortality [9
In conclusion, AE is among the most dangerous zoonotic diseases in the world. In recent years, its frequency has increasing due to transmission of the disease from dogs to humans. In AE disease, the liver is the most commonly invaded organ and due to dissemination of surrounding structures, lymphatic and vessels, it mimics malignant neoplasms. AE is a serious cause of morbidity and mortality. As in our patient, AE can invade the hepatic veins and inferior vena cava leading to BCS. In patients that apply to clinics with BCS, AE, although rare, should be considered among the etiological causes.