Pancreatic location of hydatid disease is rare (less than 1%) compared to the other sites of hydatid disease [1, 2]. The mode of infestation is either hematogenous, when there is a failure of trapping oncospherse by the liver and lung filters, or more rarely through lymphatic spread [1]. The location is solitary in the pancreas in 90% of cases. The cyst can be found in the head in 50-57%, in the body in 24-34% or in the tail in 16-19% [3]. Clinical presentation varies according to the anatomic location and potential complications of the cyst (e.g. infection, rupture, biliary or intestinal fistula, segmental portal hypertension, vascular thrombosis, acute or chronic pancreatitis) [3]. With respect to the pathogenesis of pancreatitis, such as liver cysts [12, 13], pancreatic hydatid cysts may cause acute pancreatitis [4–11]. While parasite migration into the common bile duct is advocated as the etiological mechanism to explain acute pancreatitis caused by liver hydatidosis, it remains unclear why some patients affected by pancreatic cysts develop this complication. Accordingly, two hypotheses are posited: main pancreatic duct compression caused by the cyst itself [7] and main pancreatic duct obstruction by hydatid scolices' migration from the hydatid cyst [6, 8, 9]. To date, and to the best of our knowledge, only 8 cases of acute pancreatitis due to pancreatic hydatid cyst have been reported [4–11].

The mean age of the patients was 28 years, with a range of 18-38 years. The ratio of men to women was 3. The cyst was found in the body (n = 4), tail (n = 2) or head (n = 2). The location was solitarily in the pancreas (n = 7), and associated with a liver hydatid cyst (n = 1) [9]. No specific complaints or signs at physical examination are known to distinguish hydatid cyst from other etiology of acute pancreatitis. Therefore, the final diagnosis was made only after either ultrasonography or computed tomography.

Ultrasonography will typically demonstrate a multivesicular cyst, limited by a clean wall, containing daughter cysts and some peripheral calcifications [2]. Computed tomographic findings, such as rounded cystic lesions with curvilinear calcification may allow to make the diagnosis in the appropriate clinical setting [14]. Computed tomography will also identify the prognostic stage of acute pancreatitis, which allows first, to establish the monitoring protocol, and second, to specify the time of surgery. Moreover, the abdominal CT scan can also provide indirect evidence indicating the opening of the cyst in the main pancreatic duct: the dilation of Wirsung's canal and the detachment of the hydatid membrane, which was the case in our patient. Regarding the direct sign, only Diop et al. had reported direct visualization of the migration of hydatid material from a hydatid cyst of the pancreas into the main pancreatic duct, based on data from magnetic resonance imaging and endoscopic ultrasound [9]. The cyst diameter ranged from 30 to 100 mm. In our patient, the mass size was 100 mm (missing value = 1).

Surgical treatment of hydatid pancreatic cysts may be challenging. Furthermore, depending on the cyst's location, several procedures have been suggested, ranging from cyst fenestration, internal derivation, to central or distal pancreatectomy [5–7, 15–17]. As the presence of a cystopancreatic fistula may cause a long-lasting pancreatic leak after fenestration [5, 16], a derivative/resective procedure is preferred in such cases. When conservative treatment is performed within local conditions that do not allow an internal derivation (inflammation seen in connection with acute pancreatitis), a possible postoperative pancreatic fistula can be treated using endoscopic retrogradecholangiopancreatography (ERCP) and placing a pancreatic stent [10]. Bedioui et al. [16] suggested intraoperative cholangiopancreatography to identify a fistula between the cyst and the main pancreatic duct, leading thus to the most appropriate surgical treatment. This diagnosis could be given preoperatively through magnetic resonance imaging or endoscopic ultrasound, allowing for planning the correct surgical strategy [9, 16]. In this review of literature, procedures that have been performed were as following: left pancreatectomy (n = 5) from which one was with splenic preservation, cyst fenestration (n = 2) and total cystectomy (n = 1). No recurrence was diagnosed after a mean of 13 month (missing value = 1).

Hydatid cyst of the pancreas is an extremely rare pathology but it may be a causal factor in acute pancreatitis, especially in endemic areas. Radiological examinations may help clinicians in diagnosing cystic masses in the pancreas. In the case of acute pancreatitis due to pancreatic hydatid cyst, there is definitely a closed relationship between the main pancreatic duct and the pancreatic cyst, imposing a derivative or a resective procedure.

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.