Intrabiliary ruptured cyst hydatid

Dear Editor,

the publication on “Intrabiliary Ruptured Cyst Hydatid” is very interesting. In this case, Mermi et al. mentioned that “In geographical areas endemic for hydatid disease, cyst rapture into the bile ducts should be included in the differential diagnosis even in seronegative cases, although it is not typical for hydatid cyst to be found as a mass lesion in the liver on US in patients with right upper quadrant pain and jaundice. Detailed imaging by MRI/MRCP should be done” [1]. There are some points for discussion. First, the main question is whether the diagnostic imaging is sufficient for diagnosis of hydatid cyst. In fact, the parasitic cystic lesion at liver and biliary tract is not uncommon, but the hydatid cyst usually presents a classical big cystic lesion [2]. The main differential diagnosis, for tropical countries, is cysticercosis [2]. Second, a possible answer to the question of why there is a seronegative result in the present case might be due to the basic clinical pathology principle, namely the prozone effect [3,4]. In immunodiagnosis or serodiagnosis, if there are excessive antigens, the false negative can be derived, and this might be the explanation for the present case. The way to resolve the problem and confirm diagnosis by serological test is by pre-analytical specimen dilution before repeated serological examination.

Conflict of interest

The authors report no conflict of interest.