RESUMEN
INTRODUCTION: Bone hydatidosis is a rare disease. It is characterised by discreet and nonspecific symptomatology that makes the diagnosis late and the treatment difficult to manage. PRESENTATION OF CASE: We report the case of a 29-year-old woman hospitalised for right hip pain with a lytic image well limited in the upper extremity of the right femur. We retained the diagnosis of a unicameral bone cyst which weakens the cortical bone. Osteosynthesis with a Gamma nailing was indicated to prevent fractures. At five years of follow up, the patient presented a pain recurrence. Radiographs showed almost a destruction of the upper extremity of the femur and a loosening of osteosynthesis material. Thus, we indicated the removal of the osteosynthesis material and a bone biopsy were performed. Histopathological examination leads to an osseous hydatid cyst diagnosis. We decide to carry out a carcinological resection and reconstruction with a mega prosthesis. The clinical results were excellent and no recurrence for three years follow-up. DISCUSSION: Bone hydatidosis is challenging to diagnose at an early stage, mainly when it simulates a bone cyst. Moreover, the consequence of a late or misdiagnosed bone hydatidosis is devastating. Because of its diffuse and infiltrative character, it gradually invades the whole bone, which makes it more complicated to manage. CONCLUSION: Bone hydatidosis is a rare disease that can simulate other pathologies like a bone cyst in our case. In these situations, the anamnesis has a primordial place to guide the diagnosis and investigations.