Pathological fracture of femoral neck in a middle-aged woman: a rare presentation of primary hydatid cyst disease in humans.

Hydatid disease in humans is caused by Echinococcus granulosus. It most commonly involves the liver and, to a lesser extent, the lungs and spleen; however, it is known to involve other areas, too. Involvement of bone by hydatid cyst is rare. Here, we describe the case of a 37-year-old woman who presented with pain in the left groin and swelling in the left thigh. The radiological imaging showed a fracture of the femoral neck and cysts in the shaft of the femur. Diagnosis of hydatid cyst was confirmed on the basis of histopathology of biopsy specimens. The patient recovered after surgical excision of the cyst. This case illustrates the various sites and presentations of hydatid cyst disease, and the need to investigate for it if cystic bony lesions are encountered especially in endemic regions, as a delay in diagnosis can lead to long-term morbidity and even death.