Figure 2: intraoperative imaging of the cyst contents
The immediate postoperative course was uneventful and the patient was discharged home on the seventh postoperative day. Albendazole was given to the patient for four month with good tolerance. The 24-month follow-up did not show any recurrence but the patient still had a limp when walking due to the significant osteolysis.
DISCUSSION :
Hydatid cysts are a common parasitic disease in endemic countries. It frequently occurs in the liver and lungs. Bone localisation is rare with a frequency of 1 to 2% (4).
Pelvic involvement which occurs by haematogenous route, concerns the iliac bone in 16.4%. It has a poor functional prognosis because of its extension to the coxofemoral joint and more rarely to the sacrum (5).
The clinical signs of hydatid bone cysts are not specific and depend on location of the cyst. They are dominated by pain. The clinical examination is poor and often shows a discrete lameness on walking (6).
The standard X-ray remains the reference examination for the diagnosis. It most often shows poorly limited areolar lytic images of the areola, with the classic ”honeycomb” appearance without any reaction or regional decalcification (6)
The interest of ultrasound is essentially to explore the soft parts in search of an abscess. It contributes, as does the chest X-ray, in search of associated visceral lesions which may help in the diagnosis. CT and MRI specify the bone involvement, assess the locoregional extent and constitute an excellent means of monitoring the evolution of the disease (7).
Despite the various therapeutic methods relapse rates after partial removal are very high (8).
its treatment is difficult due to frequent recurrences, especially in certain locations such as ilium and hip, which accounts for 2% of hydatid cysts in bone, and radical surgery remains morbid and difficult to achieve (9).
Despite the various therapeutic methods relapse rates after partial removal are very high.
The hydatid bone cyst is invasive and aggressive due to the absence of a pericyst limiting the extension of the lesions, intra-osseous hydatid cysts only exceptionally calcify, whereas their extension into the soft tissue may calcify, and management remains difficult and cumbersome (10).
Conservative surgical treatment under cover of prolonged medial antiparasitic therapy may be an alternative to morbid surgery in cases of very high risk and for extensive lesions (9)
Currently, microwave ablation may be a useful therapeutic alternative in the treatment of patients with hydatid bone cysts, in order to prevent the disease from relapse (11).