ABSTRACT

To describe a rare instance of a hydatid cyst that caused severe and progressive lower back pain and was misdiagnosed as sacroiliitis.

Hydatid disease or hydatidosis is a serious human cestode infection worldwide with a characteristic geographic distribution. The liver and lungs are the most frequently involved organs. Bone involvement is seen in less than 4% of cases, and vertebral hydatid disease is uncommon. The symptoms of sacroiliac joint and lower back pain cause difficulties for differential diagnosis, and this rare condition may be misdiagnosed.

We report a case of a 21-year-old woman with hip pain caused by a secondary hydatid cyst of the sacral and pelvic areas. The patient was diagnosed with sacroiliitis and sciatica in another center. As treatment for these failed, the patient was referred to our clinic. Physical examination and radiological tests revealed iliac bone lesions starting from the left sacral area and extending to the sacroiliac joint.

Following medical treatment, curettage and grafting were performed. Macroscopic imaging and histopathological evaluation of the material that was removed from the lesion field were consistent with hydatid disease. No recurrence was detected and the patient was free of symptoms after 11 months of follow-up.

Bone hydatid disease can be misdiagnosed in the early periods. When it progresses, it results in destruction of the bone. In patients with a history of hydatid disease and with musculoskeletal complaints, the possibility of hydatid cysts should be kept in mind. There are ongoing debates as to whether bone grafting or acrylic cement are safer for the management of the remaining cavity, and we consider bone grafting to be the safer treatment.